StreamReader 建構函式

參考

定義

命名空間:: System.IO

組件:: System.IO.dll

組件:: System.Runtime.dll

組件:: System.Runtime.Extensions.dll

組件:: mscorlib.dll

組件:: netstandard.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

為指定的資料流，初始化 StreamReader 類別的新執行個體。

多載

StreamReader(Stream)	為指定的資料流，初始化 StreamReader 類別的新執行個體。
StreamReader(Stream, Encoding, Boolean, Int32, Boolean)	根據指定的字元編碼、位元順序標記偵測選項和緩衝區大小，為指定的資料流初始化 StreamReader 類別的新執行個體，並選擇性讓資料流保持開啟。
StreamReader(String, Encoding, Boolean, FileStreamOptions)	使用指定的字元編碼、位元組順序標記偵測選項，並使用指定的FileStreamOptions物件設定，初始化指定檔案路徑類別的新實例StreamReader。
StreamReader(String, Encoding, Boolean, Int32)	使用指定的字元編碼、位元組順序標記偵測選項和緩衝區大小，為指定的檔案名稱初始化 StreamReader 類別的新執行個體。
StreamReader(Stream, Encoding, Boolean, Int32)	使用指定的字元編碼、位元組順序標記偵測選項和緩衝區大小，為指定的資料流初始化 StreamReader 類別的新執行個體。
StreamReader(Stream, Encoding, Boolean)	使用指定的字元編碼和位元組順序標記偵測選項，為指定的資料流初始化 StreamReader 類別的新執行個體。
StreamReader(String, Encoding, Boolean)	使用指定的字元編碼和位元組順序標記偵測選項，為指定的檔案名稱初始化 StreamReader 類別的新執行個體。
StreamReader(String, FileStreamOptions)	使用預設編碼方式，針對指定的檔案路徑，初始化類別的新實例 StreamReader ，以在檔案開頭啟用位元組順序標記的偵測，並使用指定的 FileStreamOptions 對象進行設定。
StreamReader(String, Boolean)	使用指定的位元組順序標記偵測選項，為指定的檔案名稱初始化 StreamReader 類別的新執行個體。
StreamReader(Stream, Encoding)	使用指定的字元編碼，針對指定的資料流初始化 StreamReader 類別的新執行個體。
StreamReader(Stream, Boolean)	使用指定的位元組順序標記偵測選項，針對指定的資料流初始化 StreamReader 類別的新執行個體。
StreamReader(String)	為指定的檔名初始化 StreamReader 類別的新執行個體。
StreamReader(String, Encoding)	使用指定的字元編碼，針對指定的檔案名稱初始化 StreamReader 類別的新執行個體。

StreamReader(Stream)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

為指定的資料流，初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::IO::Stream ^ stream);

public StreamReader (System.IO.Stream stream);

new System.IO.StreamReader : System.IO.Stream -> System.IO.StreamReader

Public Sub New (stream As Stream)

參數

stream: Stream

要讀取的資料流。

例外狀況

ArgumentException

stream 不支援讀取。

ArgumentNullException

stream 為 null。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

using namespace System;
using namespace System::IO;
int main()
{
   String^ path = "c:\\temp\\MyTest.txt";
   try
   {
      if ( File::Exists( path ) )
      {
         File::Delete( path );
      }
      StreamWriter^ sw = gcnew StreamWriter( path );
      try
      {
         sw->WriteLine( "This" );
         sw->WriteLine( "is some text" );
         sw->WriteLine( "to test" );
         sw->WriteLine( "Reading" );
      }
      finally
      {
         delete sw;
      }

      FileStream^ fs = gcnew FileStream( path,FileMode::Open );
      try
      {
         StreamReader^ sr = gcnew StreamReader( fs );
         try
         {
            while ( sr->Peek() >= 0 )
            {
               Console::WriteLine( sr->ReadLine() );
            }
         }
         finally
         {
            delete sr;
         }
      }
      finally
      {
         delete fs;
      }
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "The process failed: {0}", e );
   }
}

using System;
using System.IO;

class Test
{
    public static void Main()
    {
        string path = @"c:\temp\MyTest.txt";

        try
        {
            if (File.Exists(path))
            {
                File.Delete(path);
            }

            using (StreamWriter sw = new StreamWriter(new FileStream(path, FileMode.CreateNew)))
            {
                sw.WriteLine("This");
                sw.WriteLine("is some text");
                sw.WriteLine("to test");
                sw.WriteLine("reading");
            }

            using (StreamReader sr = new StreamReader(new FileStream(path, FileMode.Open)))
            {
                while (sr.Peek() >= 0)
                {
                    Console.WriteLine(sr.ReadLine());
                }
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }
    }
}

Imports System.IO

Public Class Test

    Public Shared Sub Main()
        Dim path As String = "c:\temp\MyTest.txt"

        Try
            If File.Exists(path) Then
                File.Delete(path)
            End If

            Dim sw As StreamWriter = New StreamWriter(path)
            sw.WriteLine("This")
            sw.WriteLine("is some text")
            sw.WriteLine("to test")
            sw.WriteLine("Reading")
            sw.Close()

            Dim fs As FileStream = New FileStream(path, FileMode.Open)

            Dim sr As StreamReader = New StreamReader(fs)

            Do While sr.Peek() >= 0
                Console.WriteLine(sr.ReadLine())
            Loop
            sr.Close()
            fs.Close()
        Catch e As Exception
            Console.WriteLine("The process failed: {0}", e.ToString())
        End Try
    End Sub
End Class

備註

這個建構函式會將編碼初始化為 UTF8Encoding、 BaseStream 使用 stream 參數的屬性，並將內部緩衝區大小初始化為1024個字節。

StreamReader呼叫時StreamReader.Dispose，所提供Stream物件的物件會呼叫 Dispose() 。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法解譯，而且可能會導致擲回例外狀況。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(Stream, Encoding, Boolean, Int32, Boolean)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

根據指定的字元編碼、位元順序標記偵測選項和緩衝區大小，為指定的資料流初始化 StreamReader 類別的新執行個體，並選擇性讓資料流保持開啟。

public:
 StreamReader(System::IO::Stream ^ stream, System::Text::Encoding ^ encoding, bool detectEncodingFromByteOrderMarks, int bufferSize, bool leaveOpen);

public StreamReader (System.IO.Stream stream, System.Text.Encoding encoding, bool detectEncodingFromByteOrderMarks, int bufferSize, bool leaveOpen);

public StreamReader (System.IO.Stream stream, System.Text.Encoding? encoding = default, bool detectEncodingFromByteOrderMarks = true, int bufferSize = -1, bool leaveOpen = false);

new System.IO.StreamReader : System.IO.Stream * System.Text.Encoding * bool * int * bool -> System.IO.StreamReader

Public Sub New (stream As Stream, encoding As Encoding, detectEncodingFromByteOrderMarks As Boolean, bufferSize As Integer, leaveOpen As Boolean)

Public Sub New (stream As Stream, Optional encoding As Encoding = Nothing, Optional detectEncodingFromByteOrderMarks As Boolean = true, Optional bufferSize As Integer = -1, Optional leaveOpen As Boolean = false)

參數

stream: Stream

要讀取的資料流。

encoding: Encoding

要使用的字元編碼。

detectEncodingFromByteOrderMarks: Boolean

true 表示在檔案開頭尋找位元順序標記；否則為 false。

bufferSize: Int32

最小緩衝區大小。

leaveOpen: Boolean

true 表示在處置 StreamReader 物件之後，將資料流保持開啟；否則為 false。

備註

除非您將 leaveOpen 參數設定為 true，StreamReader否則呼叫時StreamReader.Dispose，所提供Stream物件的物件會呼叫 Dispose() 。

緩衝區大小，以16位字元數為單位，由 bufferSize 參數設定。如果 bufferSize 小於最小允許大小 (128 個字元) ，則會使用最小允許的大小。

這個建構函式可讓您在第一次從 StreamReader 物件讀取時變更編碼方式。 detectEncodingFromByteOrderMarks如果參數為 true，建構函式會查看數據流的前四個字節來偵測編碼。它會自動辨識 UTF-8、小端 UTF-16、big-endian UTF-16、small-endian UTF-32 和 big-endian UTF-32 文字，如果檔案以適當的位元組順序標記開頭。否則，會使用使用者提供的編碼方式。如需詳細資訊，請參閱 Encoding.GetPreamble 方法。

注意

從 Stream讀取時，使用大小與數據流內部緩衝區相同的緩衝區會更有效率。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法正確解譯，而且可能會導致擲回例外狀況。

適用於

StreamReader(String, Encoding, Boolean, FileStreamOptions)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的字元編碼、位元組順序標記偵測選項，並使用指定的FileStreamOptions物件設定，初始化指定檔案路徑類別的新實例StreamReader。

public:
 StreamReader(System::String ^ path, System::Text::Encoding ^ encoding, bool detectEncodingFromByteOrderMarks, System::IO::FileStreamOptions ^ options);

public StreamReader (string path, System.Text.Encoding encoding, bool detectEncodingFromByteOrderMarks, System.IO.FileStreamOptions options);

new System.IO.StreamReader : string * System.Text.Encoding * bool * System.IO.FileStreamOptions -> System.IO.StreamReader

Public Sub New (path As String, encoding As Encoding, detectEncodingFromByteOrderMarks As Boolean, options As FileStreamOptions)

參數

path: String

要讀取的完整檔案路徑。

encoding: Encoding

要使用的字元編碼。

detectEncodingFromByteOrderMarks: Boolean

表示是否在檔案開頭尋找位元組順序標記。

options: FileStreamOptions

物件，指定基礎 FileStream的組態選項。

例外狀況

ArgumentException

stream 不可讀取。

      -or-

path 為空字串 ("")。

ArgumentNullException

path、encoding 或 options 為 null。

FileNotFoundException

找不到檔案。

DirectoryNotFoundException

指定的路徑無效，例如位於未對應的磁碟機上。

NotSupportedException

path 包含不正確或無效的檔案名稱、目錄名稱或磁碟區標籤語法。

另請參閱

適用於

StreamReader(String, Encoding, Boolean, Int32)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的字元編碼、位元組順序標記偵測選項和緩衝區大小，為指定的檔案名稱初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::String ^ path, System::Text::Encoding ^ encoding, bool detectEncodingFromByteOrderMarks, int bufferSize);

public StreamReader (string path, System.Text.Encoding encoding, bool detectEncodingFromByteOrderMarks, int bufferSize);

new System.IO.StreamReader : string * System.Text.Encoding * bool * int -> System.IO.StreamReader

Public Sub New (path As String, encoding As Encoding, detectEncodingFromByteOrderMarks As Boolean, bufferSize As Integer)

參數

path: String

要讀取的完整檔案路徑。

encoding: Encoding

要使用的字元編碼。

detectEncodingFromByteOrderMarks: Boolean

表示是否在檔案開頭尋找位元組順序標記。

bufferSize: Int32

最小緩衝區大小，使用 16 位元字元的數字。

例外狀況

ArgumentException

path 為空字串 ("")。

ArgumentNullException

path 或 encoding 為 null。

FileNotFoundException

找不到檔案。

DirectoryNotFoundException

指定的路徑無效，例如位於未對應的磁碟機上。

NotSupportedException

path 包含不正確或無效的檔案名稱、目錄名稱或磁碟區標籤語法。

ArgumentOutOfRangeException

buffersize 小於或等於零。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

void getNewStreamReader()
{
   
   //Get a new StreamReader in ASCII format from a
   //file using a buffer and byte order mark detection
   StreamReader^ srAsciiFromFileFalse512 = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //file with byte order mark detection = false
   StreamReader^ srAsciiFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a file 
   StreamReader^ srAsciiFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //file with byte order mark detection = false
   StreamReader^ srFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",false );
   
   //Get a new StreamReader from a file
   StreamReader^ srFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt" );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false and a buffer
   StreamReader^ srAsciiFromStreamFalse512 = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false
   StreamReader^ srAsciiFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a FileStream
   StreamReader^ srAsciiFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //FileStream with byte order mark detection = false
   StreamReader^ srFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),false );
   
   //Get a new StreamReader from a FileStream
   StreamReader^ srFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ) );
}

private void getNewStreamReader()
{
    //Get a new StreamReader in ASCII format from a
    //file using a buffer and byte order mark detection
    StreamReader srAsciiFromFileFalse512 =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //file with byte order mark detection = false
    StreamReader srAsciiFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a file
    StreamReader srAsciiFromFile =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //file with byte order mark detection = false
    StreamReader srFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt", false);
    //Get a new StreamReader from a file
    StreamReader srFromFile =
        new StreamReader("C:\\Temp\\Test.txt");
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false and a buffer
    StreamReader srAsciiFromStreamFalse512 = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false
    StreamReader srAsciiFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a FileStream
    StreamReader srAsciiFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //FileStream with byte order mark detection = false
    StreamReader srFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        false);
    //Get a new StreamReader from a FileStream
    StreamReader srFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"));
}

Private Sub getNewStreamReader()
    Dim S As Stream = File.OpenRead("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'file using a buffer and byte order mark detection
    Dim SrAsciiFromFileFalse512 As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'file with byte order mark detection = false
    Dim SrAsciiFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a file 
    Dim SrAsciiFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'file with byte order mark detection = false        
    Dim SrFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", False)
    'Get a new StreamReader from a file
    Dim SrFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false and a buffer
    Dim SrAsciiFromStreamFalse512 As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false
    Dim SrAsciiFromStreamFalse = New StreamReader(S, _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a FileStream
    Dim SrAsciiFromStream As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'FileStream with byte order mark detection = false
    Dim SrFromStreamFalse As StreamReader = New StreamReader(S, False)
    'Get a new StreamReader from a FileStream
    Dim SrFromStream As StreamReader = New StreamReader(S)

End Sub

備註

這個建構函式會初始化參數所 encoding 指定的編碼方式。

這個建構函式可讓您第一次從 StreamReader 物件讀取時變更編碼方式。參數 detectEncodingFromByteOrderMarks 會藉由查看數據流的前四個字節來偵測編碼。它會自動辨識 UTF-8、小端 UTF-16、big-endian UTF-16、small-endian UTF-32 和 big-endian UTF-32 文字，如果檔案以適當的位元組順序標記開頭。否則，會使用使用者提供的編碼方式。如需詳細資訊，請參閱 Encoding.GetPreamble 方法。

緩衝區大小，以16位字元數為單位，由 bufferSize 參數設定。如果 bufferSize 小於最小允許大小 (128 個字元) ，則會使用最小允許的大小。

參數 path 可以是檔名，包括通用命名慣例上的檔案， (UNC) 共用。

參數 path 不需要是儲存在磁碟上的檔案;它可以是支援使用數據流存取之系統的任何部分。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法解譯，而且可能會導致擲回例外狀況。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(Stream, Encoding, Boolean, Int32)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的字元編碼、位元組順序標記偵測選項和緩衝區大小，為指定的資料流初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::IO::Stream ^ stream, System::Text::Encoding ^ encoding, bool detectEncodingFromByteOrderMarks, int bufferSize);

public StreamReader (System.IO.Stream stream, System.Text.Encoding encoding, bool detectEncodingFromByteOrderMarks, int bufferSize);

new System.IO.StreamReader : System.IO.Stream * System.Text.Encoding * bool * int -> System.IO.StreamReader

Public Sub New (stream As Stream, encoding As Encoding, detectEncodingFromByteOrderMarks As Boolean, bufferSize As Integer)

參數

stream: Stream

要讀取的資料流。

encoding: Encoding

要使用的字元編碼。

detectEncodingFromByteOrderMarks: Boolean

表示是否在檔案開頭尋找位元組順序標記。

bufferSize: Int32

最小緩衝區大小。

例外狀況

ArgumentException

資料流不支援讀取。

ArgumentNullException

stream 或 encoding 為 null。

ArgumentOutOfRangeException

bufferSize 小於或等於零。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

void getNewStreamReader()
{
   
   //Get a new StreamReader in ASCII format from a
   //file using a buffer and byte order mark detection
   StreamReader^ srAsciiFromFileFalse512 = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //file with byte order mark detection = false
   StreamReader^ srAsciiFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a file 
   StreamReader^ srAsciiFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //file with byte order mark detection = false
   StreamReader^ srFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",false );
   
   //Get a new StreamReader from a file
   StreamReader^ srFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt" );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false and a buffer
   StreamReader^ srAsciiFromStreamFalse512 = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false
   StreamReader^ srAsciiFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a FileStream
   StreamReader^ srAsciiFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //FileStream with byte order mark detection = false
   StreamReader^ srFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),false );
   
   //Get a new StreamReader from a FileStream
   StreamReader^ srFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ) );
}

private void getNewStreamReader()
{
    //Get a new StreamReader in ASCII format from a
    //file using a buffer and byte order mark detection
    StreamReader srAsciiFromFileFalse512 =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //file with byte order mark detection = false
    StreamReader srAsciiFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a file
    StreamReader srAsciiFromFile =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //file with byte order mark detection = false
    StreamReader srFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt", false);
    //Get a new StreamReader from a file
    StreamReader srFromFile =
        new StreamReader("C:\\Temp\\Test.txt");
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false and a buffer
    StreamReader srAsciiFromStreamFalse512 = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false
    StreamReader srAsciiFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a FileStream
    StreamReader srAsciiFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //FileStream with byte order mark detection = false
    StreamReader srFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        false);
    //Get a new StreamReader from a FileStream
    StreamReader srFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"));
}

Private Sub getNewStreamReader()
    Dim S As Stream = File.OpenRead("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'file using a buffer and byte order mark detection
    Dim SrAsciiFromFileFalse512 As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'file with byte order mark detection = false
    Dim SrAsciiFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a file 
    Dim SrAsciiFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'file with byte order mark detection = false        
    Dim SrFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", False)
    'Get a new StreamReader from a file
    Dim SrFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false and a buffer
    Dim SrAsciiFromStreamFalse512 As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false
    Dim SrAsciiFromStreamFalse = New StreamReader(S, _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a FileStream
    Dim SrAsciiFromStream As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'FileStream with byte order mark detection = false
    Dim SrFromStreamFalse As StreamReader = New StreamReader(S, False)
    'Get a new StreamReader from a FileStream
    Dim SrFromStream As StreamReader = New StreamReader(S)

End Sub

備註

緩衝區大小，以16位字元數為單位，由 bufferSize 參數設定。如果 bufferSize 小於最小允許大小 (128 個字元) ，則會使用最小允許的大小。

StreamReader呼叫時StreamReader.Dispose，所提供Stream物件的物件會呼叫 Dispose() 。

注意

從 Stream讀取時，使用大小與數據流內部緩衝區相同的緩衝區會更有效率。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法解譯，而且可能會導致擲回例外狀況。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(Stream, Encoding, Boolean)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的字元編碼和位元組順序標記偵測選項，為指定的資料流初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::IO::Stream ^ stream, System::Text::Encoding ^ encoding, bool detectEncodingFromByteOrderMarks);

public StreamReader (System.IO.Stream stream, System.Text.Encoding encoding, bool detectEncodingFromByteOrderMarks);

new System.IO.StreamReader : System.IO.Stream * System.Text.Encoding * bool -> System.IO.StreamReader

Public Sub New (stream As Stream, encoding As Encoding, detectEncodingFromByteOrderMarks As Boolean)

參數

stream: Stream

要讀取的資料流。

encoding: Encoding

要使用的字元編碼。

detectEncodingFromByteOrderMarks: Boolean

表示是否在檔案開頭尋找位元組順序標記。

例外狀況

ArgumentException

stream 不支援讀取。

ArgumentNullException

stream 或 encoding 為 null。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

void getNewStreamReader()
{
   
   //Get a new StreamReader in ASCII format from a
   //file using a buffer and byte order mark detection
   StreamReader^ srAsciiFromFileFalse512 = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //file with byte order mark detection = false
   StreamReader^ srAsciiFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a file 
   StreamReader^ srAsciiFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //file with byte order mark detection = false
   StreamReader^ srFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",false );
   
   //Get a new StreamReader from a file
   StreamReader^ srFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt" );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false and a buffer
   StreamReader^ srAsciiFromStreamFalse512 = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false
   StreamReader^ srAsciiFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a FileStream
   StreamReader^ srAsciiFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //FileStream with byte order mark detection = false
   StreamReader^ srFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),false );
   
   //Get a new StreamReader from a FileStream
   StreamReader^ srFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ) );
}

private void getNewStreamReader()
{
    //Get a new StreamReader in ASCII format from a
    //file using a buffer and byte order mark detection
    StreamReader srAsciiFromFileFalse512 =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //file with byte order mark detection = false
    StreamReader srAsciiFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a file
    StreamReader srAsciiFromFile =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //file with byte order mark detection = false
    StreamReader srFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt", false);
    //Get a new StreamReader from a file
    StreamReader srFromFile =
        new StreamReader("C:\\Temp\\Test.txt");
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false and a buffer
    StreamReader srAsciiFromStreamFalse512 = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false
    StreamReader srAsciiFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a FileStream
    StreamReader srAsciiFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //FileStream with byte order mark detection = false
    StreamReader srFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        false);
    //Get a new StreamReader from a FileStream
    StreamReader srFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"));
}

Private Sub getNewStreamReader()
    Dim S As Stream = File.OpenRead("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'file using a buffer and byte order mark detection
    Dim SrAsciiFromFileFalse512 As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'file with byte order mark detection = false
    Dim SrAsciiFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a file 
    Dim SrAsciiFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'file with byte order mark detection = false        
    Dim SrFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", False)
    'Get a new StreamReader from a file
    Dim SrFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false and a buffer
    Dim SrAsciiFromStreamFalse512 As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false
    Dim SrAsciiFromStreamFalse = New StreamReader(S, _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a FileStream
    Dim SrAsciiFromStream As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'FileStream with byte order mark detection = false
    Dim SrFromStreamFalse As StreamReader = New StreamReader(S, False)
    'Get a new StreamReader from a FileStream
    Dim SrFromStream As StreamReader = New StreamReader(S)

End Sub

備註

這個建構函式會初始化參數所 encoding 指定的編碼方式、 BaseStream 使用 stream 參數的屬性，並將內部緩衝區大小初始化為 1024 個字節。

參數 detectEncodingFromByteOrderMarks 會藉由查看數據流的前四個字節來偵測編碼。它會自動辨識 UTF-8、小端 UTF-16、big-endian UTF-16、small-endian UTF-32 和 big-endian UTF-32 文字，如果檔案以適當的位元組順序標記開頭。否則，會使用使用者提供的編碼方式。如需詳細資訊，請參閱 Encoding.GetPreamble 方法。

StreamReader呼叫時StreamReader.Dispose，所提供Stream物件的物件會呼叫 Dispose() 。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法解譯，而且可能會導致擲回例外狀況。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(String, Encoding, Boolean)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的字元編碼和位元組順序標記偵測選項，為指定的檔案名稱初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::String ^ path, System::Text::Encoding ^ encoding, bool detectEncodingFromByteOrderMarks);

public StreamReader (string path, System.Text.Encoding encoding, bool detectEncodingFromByteOrderMarks);

new System.IO.StreamReader : string * System.Text.Encoding * bool -> System.IO.StreamReader

Public Sub New (path As String, encoding As Encoding, detectEncodingFromByteOrderMarks As Boolean)

參數

path: String

要讀取的完整檔案路徑。

encoding: Encoding

要使用的字元編碼。

detectEncodingFromByteOrderMarks: Boolean

表示是否在檔案開頭尋找位元組順序標記。

例外狀況

ArgumentException

path 為空字串 ("")。

ArgumentNullException

path 或 encoding 為 null。

FileNotFoundException

找不到檔案。

DirectoryNotFoundException

指定的路徑無效，例如位於未對應的磁碟機上。

NotSupportedException

path 包含不正確或無效的檔案名稱、目錄名稱或磁碟區標籤語法。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

void getNewStreamReader()
{
   
   //Get a new StreamReader in ASCII format from a
   //file using a buffer and byte order mark detection
   StreamReader^ srAsciiFromFileFalse512 = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //file with byte order mark detection = false
   StreamReader^ srAsciiFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a file 
   StreamReader^ srAsciiFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //file with byte order mark detection = false
   StreamReader^ srFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",false );
   
   //Get a new StreamReader from a file
   StreamReader^ srFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt" );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false and a buffer
   StreamReader^ srAsciiFromStreamFalse512 = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false
   StreamReader^ srAsciiFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a FileStream
   StreamReader^ srAsciiFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //FileStream with byte order mark detection = false
   StreamReader^ srFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),false );
   
   //Get a new StreamReader from a FileStream
   StreamReader^ srFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ) );
}

private void getNewStreamReader()
{
    //Get a new StreamReader in ASCII format from a
    //file using a buffer and byte order mark detection
    StreamReader srAsciiFromFileFalse512 =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //file with byte order mark detection = false
    StreamReader srAsciiFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a file
    StreamReader srAsciiFromFile =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //file with byte order mark detection = false
    StreamReader srFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt", false);
    //Get a new StreamReader from a file
    StreamReader srFromFile =
        new StreamReader("C:\\Temp\\Test.txt");
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false and a buffer
    StreamReader srAsciiFromStreamFalse512 = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false
    StreamReader srAsciiFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a FileStream
    StreamReader srAsciiFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //FileStream with byte order mark detection = false
    StreamReader srFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        false);
    //Get a new StreamReader from a FileStream
    StreamReader srFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"));
}

Private Sub getNewStreamReader()
    Dim S As Stream = File.OpenRead("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'file using a buffer and byte order mark detection
    Dim SrAsciiFromFileFalse512 As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'file with byte order mark detection = false
    Dim SrAsciiFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a file 
    Dim SrAsciiFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'file with byte order mark detection = false        
    Dim SrFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", False)
    'Get a new StreamReader from a file
    Dim SrFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false and a buffer
    Dim SrAsciiFromStreamFalse512 As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false
    Dim SrAsciiFromStreamFalse = New StreamReader(S, _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a FileStream
    Dim SrAsciiFromStream As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'FileStream with byte order mark detection = false
    Dim SrFromStreamFalse As StreamReader = New StreamReader(S, False)
    'Get a new StreamReader from a FileStream
    Dim SrFromStream As StreamReader = New StreamReader(S)

End Sub

備註

這個建構函式會初始化參數所 encoding 指定的編碼方式，並將內部緩衝區大小初始化為 1024 個字節。

參數 path 可以是檔名，包括通用命名慣例上的檔案， (UNC) 共用。

參數 path 不需要是儲存在磁碟上的檔案;它可以是支援使用數據流存取之系統的任何部分。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法解譯，而且可能會導致擲回例外狀況。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(String, FileStreamOptions)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用預設編碼方式，針對指定的檔案路徑，初始化類別的新實例 StreamReader ，以在檔案開頭啟用位元組順序標記的偵測，並使用指定的 FileStreamOptions 對象進行設定。

public:
 StreamReader(System::String ^ path, System::IO::FileStreamOptions ^ options);

public StreamReader (string path, System.IO.FileStreamOptions options);

new System.IO.StreamReader : string * System.IO.FileStreamOptions -> System.IO.StreamReader

Public Sub New (path As String, options As FileStreamOptions)

參數

path: String

要讀取的完整檔案路徑。

options: FileStreamOptions

物件，指定基礎 FileStream的組態選項。

例外狀況

ArgumentException

stream 不可讀取。

-或-

      <code data-dev-comment-type="paramref">path</code> is an empty string ("").

ArgumentNullException

path 或 options 為 null。

FileNotFoundException

找不到檔案。

DirectoryNotFoundException

指定的路徑無效，例如位於未對應的磁碟機上。

IOException

path 包含不正確或無效的檔案名稱、目錄名稱或磁碟區標籤語法。

另請參閱

適用於

StreamReader(String, Boolean)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的位元組順序標記偵測選項，為指定的檔案名稱初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::String ^ path, bool detectEncodingFromByteOrderMarks);

public StreamReader (string path, bool detectEncodingFromByteOrderMarks);

new System.IO.StreamReader : string * bool -> System.IO.StreamReader

Public Sub New (path As String, detectEncodingFromByteOrderMarks As Boolean)

參數

path: String

要讀取的完整檔案路徑。

detectEncodingFromByteOrderMarks: Boolean

表示是否在檔案開頭尋找位元組順序標記。

例外狀況

ArgumentException

path 為空字串 ("")。

ArgumentNullException

path 為 null。

FileNotFoundException

找不到檔案。

DirectoryNotFoundException

指定的路徑無效，例如位於未對應的磁碟機上。

IOException

path 包含不正確或無效的檔案名稱、目錄名稱或磁碟區標籤語法。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

void getNewStreamReader()
{
   
   //Get a new StreamReader in ASCII format from a
   //file using a buffer and byte order mark detection
   StreamReader^ srAsciiFromFileFalse512 = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //file with byte order mark detection = false
   StreamReader^ srAsciiFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a file 
   StreamReader^ srAsciiFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //file with byte order mark detection = false
   StreamReader^ srFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",false );
   
   //Get a new StreamReader from a file
   StreamReader^ srFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt" );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false and a buffer
   StreamReader^ srAsciiFromStreamFalse512 = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false
   StreamReader^ srAsciiFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a FileStream
   StreamReader^ srAsciiFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //FileStream with byte order mark detection = false
   StreamReader^ srFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),false );
   
   //Get a new StreamReader from a FileStream
   StreamReader^ srFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ) );
}

private void getNewStreamReader()
{
    //Get a new StreamReader in ASCII format from a
    //file using a buffer and byte order mark detection
    StreamReader srAsciiFromFileFalse512 =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //file with byte order mark detection = false
    StreamReader srAsciiFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a file
    StreamReader srAsciiFromFile =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //file with byte order mark detection = false
    StreamReader srFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt", false);
    //Get a new StreamReader from a file
    StreamReader srFromFile =
        new StreamReader("C:\\Temp\\Test.txt");
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false and a buffer
    StreamReader srAsciiFromStreamFalse512 = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false
    StreamReader srAsciiFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a FileStream
    StreamReader srAsciiFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //FileStream with byte order mark detection = false
    StreamReader srFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        false);
    //Get a new StreamReader from a FileStream
    StreamReader srFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"));
}

Private Sub getNewStreamReader()
    Dim S As Stream = File.OpenRead("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'file using a buffer and byte order mark detection
    Dim SrAsciiFromFileFalse512 As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'file with byte order mark detection = false
    Dim SrAsciiFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a file 
    Dim SrAsciiFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'file with byte order mark detection = false        
    Dim SrFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", False)
    'Get a new StreamReader from a file
    Dim SrFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false and a buffer
    Dim SrAsciiFromStreamFalse512 As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false
    Dim SrAsciiFromStreamFalse = New StreamReader(S, _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a FileStream
    Dim SrAsciiFromStream As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'FileStream with byte order mark detection = false
    Dim SrFromStreamFalse As StreamReader = New StreamReader(S, False)
    'Get a new StreamReader from a FileStream
    Dim SrFromStream As StreamReader = New StreamReader(S)

End Sub

備註

這個建構函式會將編碼初始化為 UTF8Encoding、 BaseStream 使用 stream 參數的屬性，並將內部緩衝區大小初始化為1024個字節。

參數 path 可以是檔名，包括通用命名慣例上的檔案， (UNC) 共用。

參數 path 不需要是儲存在磁碟上的檔案;它可以是支援使用數據流存取之系統的任何部分。

參數 detectEncodingFromByteOrderMarks 會藉由查看數據流的前四個字節來偵測編碼。它會自動辨識 UTF-8、小端 UTF-16、big-endian UTF-16、small-endian UTF-32 和 big-endian UTF-32 文字，如果檔案以適當的位元組順序標記開頭。否則， UTF8Encoding 會使用。如需詳細資訊，請參閱 Encoding.GetPreamble 方法。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(Stream, Encoding)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的字元編碼，針對指定的資料流初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::IO::Stream ^ stream, System::Text::Encoding ^ encoding);

public StreamReader (System.IO.Stream stream, System.Text.Encoding encoding);

new System.IO.StreamReader : System.IO.Stream * System.Text.Encoding -> System.IO.StreamReader

Public Sub New (stream As Stream, encoding As Encoding)

參數

stream: Stream

要讀取的資料流。

encoding: Encoding

要使用的字元編碼。

例外狀況

ArgumentException

stream 不支援讀取。

ArgumentNullException

stream 或 encoding 為 null。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

void getNewStreamReader()
{
   
   //Get a new StreamReader in ASCII format from a
   //file using a buffer and byte order mark detection
   StreamReader^ srAsciiFromFileFalse512 = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //file with byte order mark detection = false
   StreamReader^ srAsciiFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a file 
   StreamReader^ srAsciiFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //file with byte order mark detection = false
   StreamReader^ srFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",false );
   
   //Get a new StreamReader from a file
   StreamReader^ srFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt" );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false and a buffer
   StreamReader^ srAsciiFromStreamFalse512 = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false
   StreamReader^ srAsciiFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a FileStream
   StreamReader^ srAsciiFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //FileStream with byte order mark detection = false
   StreamReader^ srFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),false );
   
   //Get a new StreamReader from a FileStream
   StreamReader^ srFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ) );
}

private void getNewStreamReader()
{
    //Get a new StreamReader in ASCII format from a
    //file using a buffer and byte order mark detection
    StreamReader srAsciiFromFileFalse512 =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //file with byte order mark detection = false
    StreamReader srAsciiFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a file
    StreamReader srAsciiFromFile =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //file with byte order mark detection = false
    StreamReader srFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt", false);
    //Get a new StreamReader from a file
    StreamReader srFromFile =
        new StreamReader("C:\\Temp\\Test.txt");
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false and a buffer
    StreamReader srAsciiFromStreamFalse512 = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false
    StreamReader srAsciiFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a FileStream
    StreamReader srAsciiFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //FileStream with byte order mark detection = false
    StreamReader srFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        false);
    //Get a new StreamReader from a FileStream
    StreamReader srFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"));
}

Private Sub getNewStreamReader()
    Dim S As Stream = File.OpenRead("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'file using a buffer and byte order mark detection
    Dim SrAsciiFromFileFalse512 As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'file with byte order mark detection = false
    Dim SrAsciiFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a file 
    Dim SrAsciiFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'file with byte order mark detection = false        
    Dim SrFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", False)
    'Get a new StreamReader from a file
    Dim SrFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false and a buffer
    Dim SrAsciiFromStreamFalse512 As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false
    Dim SrAsciiFromStreamFalse = New StreamReader(S, _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a FileStream
    Dim SrAsciiFromStream As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'FileStream with byte order mark detection = false
    Dim SrFromStreamFalse As StreamReader = New StreamReader(S, False)
    'Get a new StreamReader from a FileStream
    Dim SrFromStream As StreamReader = New StreamReader(S)

End Sub

備註

字元編碼是由 encoding 參數設定，而緩衝區大小會設定為 1024 個字節。對象 StreamReader 會嘗試藉由查看數據流的前四個字節來偵測編碼。它會自動辨識 UTF-8、小端 UTF-16、big-endian UTF-16、small-endian UTF-32 和 big-endian UTF-32 文字，如果檔案以適當的位元組順序標記開頭。否則，會使用使用者提供的編碼方式。如需詳細資訊，請參閱 Encoding.GetPreamble 方法。

StreamReader呼叫時StreamReader.Dispose，所提供Stream物件的物件會呼叫 Dispose() 。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法解譯，而且可能會導致擲回例外狀況。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(Stream, Boolean)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的位元組順序標記偵測選項，針對指定的資料流初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::IO::Stream ^ stream, bool detectEncodingFromByteOrderMarks);

public StreamReader (System.IO.Stream stream, bool detectEncodingFromByteOrderMarks);

new System.IO.StreamReader : System.IO.Stream * bool -> System.IO.StreamReader

Public Sub New (stream As Stream, detectEncodingFromByteOrderMarks As Boolean)

參數

stream: Stream

要讀取的資料流。

detectEncodingFromByteOrderMarks: Boolean

表示是否在檔案開頭尋找位元組順序標記。

例外狀況

ArgumentException

stream 不支援讀取。

ArgumentNullException

stream 為 null。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

void getNewStreamReader()
{
   
   //Get a new StreamReader in ASCII format from a
   //file using a buffer and byte order mark detection
   StreamReader^ srAsciiFromFileFalse512 = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //file with byte order mark detection = false
   StreamReader^ srAsciiFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a file 
   StreamReader^ srAsciiFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //file with byte order mark detection = false
   StreamReader^ srFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",false );
   
   //Get a new StreamReader from a file
   StreamReader^ srFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt" );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false and a buffer
   StreamReader^ srAsciiFromStreamFalse512 = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false
   StreamReader^ srAsciiFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a FileStream
   StreamReader^ srAsciiFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //FileStream with byte order mark detection = false
   StreamReader^ srFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),false );
   
   //Get a new StreamReader from a FileStream
   StreamReader^ srFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ) );
}

private void getNewStreamReader()
{
    //Get a new StreamReader in ASCII format from a
    //file using a buffer and byte order mark detection
    StreamReader srAsciiFromFileFalse512 =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //file with byte order mark detection = false
    StreamReader srAsciiFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a file
    StreamReader srAsciiFromFile =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //file with byte order mark detection = false
    StreamReader srFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt", false);
    //Get a new StreamReader from a file
    StreamReader srFromFile =
        new StreamReader("C:\\Temp\\Test.txt");
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false and a buffer
    StreamReader srAsciiFromStreamFalse512 = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false
    StreamReader srAsciiFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a FileStream
    StreamReader srAsciiFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //FileStream with byte order mark detection = false
    StreamReader srFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        false);
    //Get a new StreamReader from a FileStream
    StreamReader srFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"));
}

Private Sub getNewStreamReader()
    Dim S As Stream = File.OpenRead("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'file using a buffer and byte order mark detection
    Dim SrAsciiFromFileFalse512 As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'file with byte order mark detection = false
    Dim SrAsciiFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a file 
    Dim SrAsciiFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'file with byte order mark detection = false        
    Dim SrFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", False)
    'Get a new StreamReader from a file
    Dim SrFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false and a buffer
    Dim SrAsciiFromStreamFalse512 As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false
    Dim SrAsciiFromStreamFalse = New StreamReader(S, _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a FileStream
    Dim SrAsciiFromStream As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'FileStream with byte order mark detection = false
    Dim SrFromStreamFalse As StreamReader = New StreamReader(S, False)
    'Get a new StreamReader from a FileStream
    Dim SrFromStream As StreamReader = New StreamReader(S)

End Sub

備註

這個建構函式會將編碼初始化為 UTF8Encoding、 BaseStream 使用 stream 參數的屬性，並將內部緩衝區大小初始化為1024個字節。

參數 detectEncodingFromByteOrderMarks 會藉由查看數據流的前四個字節來偵測編碼。它會自動辨識 UTF-8、小端 UTF-16、big-endian UTF-16、small-endian UTF-32 和 big-endian UTF-32 文字，如果檔案以適當的位元組順序標記開頭。如需詳細資訊，請參閱 Encoding.GetPreamble 方法。

StreamReader呼叫時StreamReader.Dispose，所提供Stream物件的物件會呼叫 Dispose() 。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(String)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

為指定的檔名初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::String ^ path);

public StreamReader (string path);

new System.IO.StreamReader : string -> System.IO.StreamReader

Public Sub New (path As String)

參數

path: String

要讀取的完整檔案路徑。

例外狀況

ArgumentException

path 為空字串 ("")。

ArgumentNullException

path 為 null。

FileNotFoundException

找不到檔案。

DirectoryNotFoundException

指定的路徑無效，例如位於未對應的磁碟機上。

IOException

path 包含不正確或無效的檔案名稱、目錄名稱或磁碟區標籤語法。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

using namespace System;
using namespace System::IO;
int main()
{
   String^ path = "c:\\temp\\MyTest.txt";
   try
   {
      if ( File::Exists( path ) )
      {
         File::Delete( path );
      }
      StreamWriter^ sw = gcnew StreamWriter( path );
      try
      {
         sw->WriteLine( "This" );
         sw->WriteLine( "is some text" );
         sw->WriteLine( "to test" );
         sw->WriteLine( "Reading" );
      }
      finally
      {
         delete sw;
      }

      StreamReader^ sr = gcnew StreamReader( path );
      try
      {
         while ( sr->Peek() >= 0 )
         {
            Console::WriteLine( sr->ReadLine() );
         }
      }
      finally
      {
         delete sr;
      }
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "The process failed: {0}", e );
   }
}

using System;
using System.IO;

class Test
{
    
    public static void Main()
    {
        string path = @"c:\temp\MyTest.txt";

        try
        {
            if (File.Exists(path))
            {
                File.Delete(path);
            }

            using (StreamWriter sw = new StreamWriter(path))
            {
                sw.WriteLine("This");
                sw.WriteLine("is some text");
                sw.WriteLine("to test");
                sw.WriteLine("Reading");
            }

            using (StreamReader sr = new StreamReader(path))
            {
                while (sr.Peek() >= 0)
                {
                    Console.WriteLine(sr.ReadLine());
                }
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }
    }
}

Imports System.IO

Public Class Test

    Public Shared Sub Main()
        Dim path As String = "c:\temp\MyTest.txt"

        Try
            If File.Exists(path) Then
                File.Delete(path)
            End If

            Dim sw As StreamWriter = New StreamWriter(path)
            sw.WriteLine("This")
            sw.WriteLine("is some text")
            sw.WriteLine("to test")
            sw.WriteLine("Reading")
            sw.Close()

            Dim sr As StreamReader = New StreamReader(path)

            Do While sr.Peek() >= 0
                Console.WriteLine(sr.ReadLine())
            Loop
            sr.Close()
        Catch e As Exception
            Console.WriteLine("The process failed: {0}", e.ToString())
        End Try
    End Sub
End Class

備註

完整的檔案路徑是由 path 參數指定。這個建構函式會將編碼初始化為 UTF8Encoding ，並將緩衝區大小初始化為 1024 位元組。

參數 path 可以是檔名，包括通用命名慣例上的檔案， (UNC) 共用。

參數 path 不需要是儲存在磁碟上的檔案;它可以是支援使用數據流存取之系統的任何部分。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法解譯，而且可能會導致擲回例外狀況。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

StreamReader(String, Encoding)

來源:: StreamReader.cs

來源:: StreamReader.cs

來源:: StreamReader.cs

使用指定的字元編碼，針對指定的檔案名稱初始化 StreamReader 類別的新執行個體。

public:
 StreamReader(System::String ^ path, System::Text::Encoding ^ encoding);

public StreamReader (string path, System.Text.Encoding encoding);

new System.IO.StreamReader : string * System.Text.Encoding -> System.IO.StreamReader

Public Sub New (path As String, encoding As Encoding)

參數

path: String

要讀取的完整檔案路徑。

encoding: Encoding

要使用的字元編碼。

例外狀況

ArgumentException

path 為空字串 ("")。

ArgumentNullException

path 或 encoding 為 null。

FileNotFoundException

找不到檔案。

DirectoryNotFoundException

指定的路徑無效，例如位於未對應的磁碟機上。

NotSupportedException

path 包含不正確或無效的檔案名稱、目錄名稱或磁碟區標籤語法。

範例

下列程式代碼範例示範此 StreamReader 建構函式。

void getNewStreamReader()
{
   
   //Get a new StreamReader in ASCII format from a
   //file using a buffer and byte order mark detection
   StreamReader^ srAsciiFromFileFalse512 = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //file with byte order mark detection = false
   StreamReader^ srAsciiFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a file 
   StreamReader^ srAsciiFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt",System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //file with byte order mark detection = false
   StreamReader^ srFromFileFalse = gcnew StreamReader(  "C:\\Temp\\Test.txt",false );
   
   //Get a new StreamReader from a file
   StreamReader^ srFromFile = gcnew StreamReader(  "C:\\Temp\\Test.txt" );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false and a buffer
   StreamReader^ srAsciiFromStreamFalse512 = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false,512 );
   
   //Get a new StreamReader in ASCII format from a
   //FileStream with byte order mark detection = false
   StreamReader^ srAsciiFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII,false );
   
   //Get a new StreamReader in ASCII format from a FileStream
   StreamReader^ srAsciiFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),System::Text::Encoding::ASCII );
   
   //Get a new StreamReader from a
   //FileStream with byte order mark detection = false
   StreamReader^ srFromStreamFalse = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ),false );
   
   //Get a new StreamReader from a FileStream
   StreamReader^ srFromStream = gcnew StreamReader( File::OpenRead(  "C:\\Temp\\Test.txt" ) );
}

private void getNewStreamReader()
{
    //Get a new StreamReader in ASCII format from a
    //file using a buffer and byte order mark detection
    StreamReader srAsciiFromFileFalse512 =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //file with byte order mark detection = false
    StreamReader srAsciiFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a file
    StreamReader srAsciiFromFile =
        new StreamReader("C:\\Temp\\Test.txt",
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //file with byte order mark detection = false
    StreamReader srFromFileFalse =
        new StreamReader("C:\\Temp\\Test.txt", false);
    //Get a new StreamReader from a file
    StreamReader srFromFile =
        new StreamReader("C:\\Temp\\Test.txt");
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false and a buffer
    StreamReader srAsciiFromStreamFalse512 = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false, 512);
    //Get a new StreamReader in ASCII format from a
    //FileStream with byte order mark detection = false
    StreamReader srAsciiFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII, false);
    //Get a new StreamReader in ASCII format from a FileStream
    StreamReader srAsciiFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        System.Text.Encoding.ASCII);
    //Get a new StreamReader from a
    //FileStream with byte order mark detection = false
    StreamReader srFromStreamFalse = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"),
        false);
    //Get a new StreamReader from a FileStream
    StreamReader srFromStream = new StreamReader(
        (System.IO.Stream)File.OpenRead("C:\\Temp\\Test.txt"));
}

Private Sub getNewStreamReader()
    Dim S As Stream = File.OpenRead("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'file using a buffer and byte order mark detection
    Dim SrAsciiFromFileFalse512 As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'file with byte order mark detection = false
    Dim SrAsciiFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a file 
    Dim SrAsciiFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt", _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'file with byte order mark detection = false        
    Dim SrFromFileFalse As StreamReader = New StreamReader("C:\Temp\Test.txt", False)
    'Get a new StreamReader from a file
    Dim SrFromFile As StreamReader = New StreamReader("C:\Temp\Test.txt")
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false and a buffer
    Dim SrAsciiFromStreamFalse512 As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII, False, 512)
    'Get a new StreamReader in ASCII format from a
    'FileStream with byte order mark detection = false
    Dim SrAsciiFromStreamFalse = New StreamReader(S, _
        System.Text.Encoding.ASCII, False)
    'Get a new StreamReader in ASCII format from a FileStream
    Dim SrAsciiFromStream As StreamReader = New StreamReader(S, _
        System.Text.Encoding.ASCII)
    'Get a new StreamReader from a
    'FileStream with byte order mark detection = false
    Dim SrFromStreamFalse As StreamReader = New StreamReader(S, False)
    'Get a new StreamReader from a FileStream
    Dim SrFromStream As StreamReader = New StreamReader(S)

End Sub

備註

這個建構函式會初始化參數所 encoding 指定的編碼方式，並將內部緩衝區大小初始化為 1024 個字節。對象 StreamReader 會嘗試藉由查看數據流的前四個字節來偵測編碼。它會自動辨識 UTF-8、小端 UTF-16、big-endian UTF-16、small-endian UTF-32 和 big-endian UTF-32 文字，如果檔案以適當的位元組順序標記開頭。否則，會使用使用者提供的編碼方式。如需詳細資訊，請參閱 Encoding.GetPreamble 方法。

參數 path 可以是檔名，包括通用命名慣例上的檔案， (UNC) 共用。

參數 path 不需要是儲存在磁碟上的檔案;它可以是支援使用數據流存取之系統的任何部分。

警告

當您編譯具有特定文化設定的一組字元，並擷取具有不同文化設定的相同字元時，字元可能無法解譯，而且可能會導致擲回例外狀況。

如需一般 I/O 工作的清單，請參閱一般 I/O 工作。

另請參閱

適用於

共用方式為

StreamReader 建構函式

定義

多載

StreamReader(Stream)

參數

例外狀況

範例

備註

另請參閱

適用於

StreamReader(Stream, Encoding, Boolean, Int32, Boolean)

參數

備註

適用於

StreamReader(String, Encoding, Boolean, FileStreamOptions)

參數

例外狀況

另請參閱

適用於

StreamReader(String, Encoding, Boolean, Int32)

參數

例外狀況

範例

備註

另請參閱

適用於

StreamReader(Stream, Encoding, Boolean, Int32)

參數

例外狀況

範例

備註

另請參閱

適用於

StreamReader(Stream, Encoding, Boolean)

參數

例外狀況

範例

備註

另請參閱

適用於

StreamReader(String, Encoding, Boolean)

參數

例外狀況

範例

備註

另請參閱

適用於

StreamReader(String, FileStreamOptions)

參數

例外狀況

另請參閱

適用於

StreamReader(String, Boolean)

參數

例外狀況

範例

備註

另請參閱

適用於

StreamReader(Stream, Encoding)

參數

例外狀況

範例

備註

另請參閱

適用於

StreamReader(Stream, Boolean)

參數

例外狀況

範例

備註

另請參閱

適用於

StreamReader(String)

參數

例外狀況

範例

備註

另請參閱