Console.SetIn(TextReader) 方法

定义

命名空间:

System

程序集:

System.Console.dll

Source:

Console.cs

将 In 属性设置为指定的 TextReader 对象。

public:
 static void SetIn(System::IO::TextReader ^ newIn);

[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
[System.Runtime.Versioning.UnsupportedOSPlatform("android")]
[System.Runtime.Versioning.UnsupportedOSPlatform("ios")]
[System.Runtime.Versioning.UnsupportedOSPlatform("tvos")]
public static void SetIn (System.IO.TextReader newIn);

[<System.Runtime.Versioning.UnsupportedOSPlatform("browser")>]
[<System.Runtime.Versioning.UnsupportedOSPlatform("android")>]
[<System.Runtime.Versioning.UnsupportedOSPlatform("ios")>]
[<System.Runtime.Versioning.UnsupportedOSPlatform("tvos")>]
static member SetIn : System.IO.TextReader -> unit

Public Shared Sub SetIn (newIn As TextReader)

参数

newIn

TextReader

一个流，它是新的标准输入。

属性

UnsupportedOSPlatformAttribute

例外

ArgumentNullException

newIn 为 null。

SecurityException

调用方没有所要求的权限。

示例

下面的示例演示 SetIn 方法的用法。 它用制表符替换字符串中的四个连续空格字符。 若要运行它，必须提供两个命令行参数。 第一个是要将标准输入流重定向到的现有文本文件的名称。 第二个是要将标准输出流重定向到的文件的名称。 此文件不需要存在。 如果它这么做，其内容将被覆盖。

using namespace System;
using namespace System::IO;

int main()
{
   array<String^>^args = Environment::GetCommandLineArgs();
   const int tabSize = 4;
   String^ usageText = "Usage: INSERTTABS inputfile.txt outputfile.txt";
   StreamWriter^ writer = nullptr;
   if ( args->Length < 3 )
   {
      Console::WriteLine( usageText );
      return 1;
   }

   try
   {
      // Attempt to open output file.
      writer = gcnew StreamWriter( args[ 2 ] );
      // Redirect standard output from the console to the output file.
      Console::SetOut( writer );
      // Redirect standard input from the console to the input file.
      Console::SetIn( gcnew StreamReader( args[ 1 ] ) );
   }
   catch ( IOException^ e ) 
   {
      TextWriter^ errorWriter = Console::Error;
      errorWriter->WriteLine( e->Message );
      errorWriter->WriteLine( usageText );
      return 1;
   }

   String^ line;
   while ( (line = Console::ReadLine()) != nullptr )
   {
      String^ newLine = line->Replace( ((String^)"")->PadRight( tabSize, ' ' ), "\t" );
      Console::WriteLine( newLine );
   }

   writer->Close();
   
   // Recover the standard output stream so that a 
   // completion message can be displayed.
   StreamWriter^ standardOutput = gcnew StreamWriter( Console::OpenStandardOutput() );
   standardOutput->AutoFlush = true;
   Console::SetOut( standardOutput );
   Console::WriteLine( "INSERTTABS has completed the processing of {0}.", args[ 1 ] );
   return 0;
}

using System;
using System.IO;

public class InsertTabs
{
    private const int tabSize = 4;
    private const string usageText = "Usage: INSERTTABS inputfile.txt outputfile.txt";
    public static int Main(string[] args)
    {
        if (args.Length < 2)
        {
            Console.WriteLine(usageText);
            return 1;
        }

        try
        {
            // Attempt to open output file.
            using (var writer = new StreamWriter(args[1]))
            {
                using (var reader = new StreamReader(args[0]))
                {
                    // Redirect standard output from the console to the output file.
                    Console.SetOut(writer);
                    // Redirect standard input from the console to the input file.
                    Console.SetIn(reader);
                    string line;
                    while ((line = Console.ReadLine()) != null)
                    {
                        string newLine = line.Replace(("").PadRight(tabSize, ' '), "\t");
                        Console.WriteLine(newLine);
                    }
                }
            }
        }
        catch(IOException e)
        {
            TextWriter errorWriter = Console.Error;
            errorWriter.WriteLine(e.Message);
            errorWriter.WriteLine(usageText);
            return 1;
        }

        // Recover the standard output stream so that a
        // completion message can be displayed.
        var standardOutput = new StreamWriter(Console.OpenStandardOutput());
        standardOutput.AutoFlush = true;
        Console.SetOut(standardOutput);
        Console.WriteLine($"INSERTTABS has completed the processing of {args[0]}.");
        return 0;
    }
}

open System
open System.IO

let tabSize = 4
let usageText = "Usage: INSERTTABS inputfile.txt outputfile.txt"

[<EntryPoint>]
let main args =
    if args.Length < 2 then
        Console.WriteLine usageText
        1
    else
        try
            // Attempt to open output file.
            use reader = new StreamReader(args[0])
            use writer = new StreamWriter(args[1])
            
            // Redirect standard output from the console to the output file.
            Console.SetOut writer
            
            // Redirect standard input from the console to the input file.
            Console.SetIn reader
            
            let mutable line = Console.ReadLine()
            while line <> null do
                let newLine = line.Replace(("").PadRight(tabSize, ' '), "\t")
                Console.WriteLine newLine
                line <- Console.ReadLine()

            // Recover the standard output stream so that a
            // completion message can be displayed.
            let standardOutput = new StreamWriter(Console.OpenStandardOutput())
            standardOutput.AutoFlush <- true
            Console.SetOut standardOutput
            Console.WriteLine $"INSERTTABS has completed the processing of {args[0]}."
            0

        with :? IOException as e -> 
            let errorWriter = Console.Error
            errorWriter.WriteLine e.Message
            errorWriter.WriteLine usageText
            1

Imports System.IO

Public Module InsertTabs
    Private Const tabSize As Integer = 4
    Private Const usageText As String = "Usage: INSERTTABS inputfile.txt outputfile.txt"
   
    Public Function Main(args As String()) As Integer
        If args.Length < 2 Then
            Console.WriteLine(usageText)
            Return 1
        End If
      
        Try
            ' Attempt to open output file.
            Using writer As New StreamWriter(args(1))
                Using reader As New StreamReader(args(0))
                    ' Redirect standard output from the console to the output file.
                    Console.SetOut(writer)
                    ' Redirect standard input from the console to the input file.
                    Console.SetIn(reader)
                    Dim line As String = Console.ReadLine()
                    While line IsNot Nothing
                        Dim newLine As String = line.Replace("".PadRight(tabSize, " "c), ControlChars.Tab)
                        Console.WriteLine(newLine)
                        line = Console.ReadLine()
                    End While
                End Using
            End Using
        Catch e As IOException
            Dim errorWriter As TextWriter = Console.Error
            errorWriter.WriteLine(e.Message)
            errorWriter.WriteLine(usageText)
            Return 1
        End Try

        ' Recover the standard output stream so that a 
        ' completion message can be displayed.
        Dim standardOutput As New StreamWriter(Console.OpenStandardOutput())
        standardOutput.AutoFlush = True
        Console.SetOut(standardOutput)
        Console.WriteLine($"INSERTTABS has completed the processing of {args(0)}.")
        Return 0
    End Function 
End Module

注解

默认情况下， In 属性设置为标准输入流。

StreamReader封装 的 FileStream 可用于从文件接收输入。

另请参阅

• TextReader
• In