Path.IsPathRooted 方法

定義

命名空間:

System.IO

組件:

System.Runtime.dll

傳回值，指出檔案路徑是否包含根目錄。

多載

IsPathRooted(String)	傳回值，指出指定的路徑字串是否包含根目錄。
IsPathRooted(ReadOnlySpan<Char>)	傳回值，指出所指定字元範圍所表示的檔案路徑是否包含根目錄。

備註

根路徑是固定在特定磁碟驅動器或 UNC 路徑的檔案路徑;它與相對於目前磁碟驅動器或工作目錄的路徑對比。 例如，在 Windows 系統上，根路徑的開頭是反斜杠 (例如“\Documents”) 或驅動器號和冒號 (，例如“C：Documents”) 。

請注意，根路徑可以是絕對 (，也就是完整) 或相對路徑。 絕對根路徑是從磁碟驅動器的根目錄到特定目錄的完整路徑。 相對根路徑會指定磁碟驅動器，但其完整路徑會根據目前的目錄解析。 下列範例會說明其間的差異。

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string relative1 = "C:Documents"; 
        ShowPathInfo(relative1);

        string relative2 = "/Documents";
        ShowPathInfo(relative2);

        string absolute = "C:/Documents";
        ShowPathInfo(absolute);
    }

    private static void ShowPathInfo(string path)
    {
        Console.WriteLine($"Path: {path}");
        Console.WriteLine($"   Rooted: {Path.IsPathRooted(path)}");
        Console.WriteLine($"   Fully qualified: {Path.IsPathFullyQualified(path)}");
        Console.WriteLine($"   Full path: {Path.GetFullPath(path)}");
        Console.WriteLine();
    }
}
// The example displays the following output when run on a Windows system:
//    Path: C:Documents
//        Rooted: True
//        Fully qualified: False
//        Full path: c:\Users\user1\Documents\projects\path\ispathrooted\Documents
//
//    Path: /Documents
//       Rooted: True
//       Fully qualified: False
//       Full path: c:\Documents
//
//    Path: C:/Documents
//       Rooted: True
//       Fully qualified: True
//       Full path: C:\Documents

Imports System.IO

Module Program
    Public Sub Main()
        Dim relative1 As String = "C:Documents" 
        ShowPathInfo(relative1)

        Dim relative2 As String = "C:Documents" 
        ShowPathInfo(relative2)

        Dim absolute As String = "C:/Documents"
        ShowPathInfo(absolute)
    End Sub

    Private Sub ShowPathInfo(filepath As String)
        Console.WriteLine($"Path: {filepath}")
        Console.WriteLine($"   Rooted: {Path.IsPathRooted(filepath)}")
        Console.WriteLine($"   Fully qualified: {Path.IsPathFullyQualified(filepath)}")
        Console.WriteLine($"   Full path: {Path.GetFullPath(filepath)}")
        Console.WriteLine()
    End Sub
End Module
' The example displays the following output when run on a Windows system:
'    Path: C:Documents
'        Rooted: True
'        Fully qualified: False
'        Full path: c:\Users\user1\Documents\projects\path\ispathrooted\Documents
'
'    Path: /Documents
'       Rooted: True
'       Fully qualified: False
'       Full path: c:\Documents
'
'    Path: C:/Documents
'       Rooted: True
'       Fully qualified: True
'       Full path: C:\Documents

IsPathRooted(String)

來源:

Path.Unix.cs

傳回值，指出指定的路徑字串是否包含根目錄。

public:
 static bool IsPathRooted(System::String ^ path);

public static bool IsPathRooted (string? path);

static member IsPathRooted : string -> bool

Public Shared Function IsPathRooted (path As String) As Boolean

參數

path

String

要測試的路徑。

傳回

Boolean

如果 path 包含根目錄，則為 true；否則為 false。

例外狀況

ArgumentException

.NET Framework 和 2.1 之前的 .NET Core 版本：path包含 中GetInvalidPathChars()定義的一或多個無效字元。

範例

下列範例示範如何使用 IsPathRooted 方法來測試三個字元串。

String^ fileName = "C:\\mydir\\myfile.ext";
String^ UncPath = "\\\\myPc\\mydir\\myfile";
String^ relativePath = "mydir\\sudir\\";
bool result;
result = Path::IsPathRooted( fileName );
Console::WriteLine( "IsPathRooted('{0}') returns {1}", fileName, result.ToString() );
result = Path::IsPathRooted( UncPath );
Console::WriteLine( "IsPathRooted('{0}') returns {1}", UncPath, result.ToString() );
result = Path::IsPathRooted( relativePath );
Console::WriteLine( "IsPathRooted('{0}') returns {1}", relativePath, result.ToString() );

// This code produces output similar to the following:
//
// IsPathRooted('C:\mydir\myfile.ext') returns True
// IsPathRooted('\\myPc\mydir\myfile') returns True
// IsPathRooted('mydir\sudir\') returns False

string fileName = @"C:\mydir\myfile.ext";
string UncPath = @"\\myPc\mydir\myfile";
string relativePath = @"mydir\sudir\";
bool result;

result = Path.IsPathRooted(fileName);
Console.WriteLine("IsPathRooted('{0}') returns {1}",
    fileName, result);

result = Path.IsPathRooted(UncPath);
Console.WriteLine("IsPathRooted('{0}') returns {1}",
    UncPath, result);

result = Path.IsPathRooted(relativePath);
Console.WriteLine("IsPathRooted('{0}') returns {1}",
    relativePath, result);

// This code produces output similar to the following:
//
// IsPathRooted('C:\mydir\myfile.ext') returns True
// IsPathRooted('\\myPc\mydir\myfile') returns True
// IsPathRooted('mydir\sudir\') returns False

Dim fileName As String = "C:\mydir\myfile.ext"
Dim UncPath As String = "\\myPc\mydir\myfile"
Dim relativePath As String = "mydir\sudir\"
Dim result As Boolean

result = Path.IsPathRooted(fileName)
Console.WriteLine("IsPathRooted('{0}') returns {1}", fileName, result)

result = Path.IsPathRooted(UncPath)
Console.WriteLine("IsPathRooted('{0}') returns {1}", UncPath, result)

result = Path.IsPathRooted(relativePath)
Console.WriteLine("IsPathRooted('{0}') returns {1}", relativePath, result)

' This code produces output similar to the following:
'
' IsPathRooted('C:\mydir\myfile.ext') returns True
' IsPathRooted('\\myPc\mydir\myfile') returns True
' IsPathRooted('mydir\sudir\') returns False

備註

IsPathRooted如果第一個字元是目錄分隔符，例如 “\”，或者路徑開頭為驅動器號和冒號，則方法會傳回 true (：) 。 例如，它會針對 path 「\\MyDir\MyFile.txt」、“C：\MyDir” 或 “C：MyDir” 等字串傳回 true 。 它會針對 path 「MyDir」 之類的字串傳回 false 。

這個方法不會驗證路徑或檔名是否存在。

如需一般 I/O 工作的清單，請參閱 一般 I/O 工作。

另請參閱

• Windows 系統上的檔案路徑格式
• 檔案和資料流 I/O
• 作法：讀取檔案中的文字
• 作法：將文字寫入檔案

IsPathRooted(ReadOnlySpan<Char>)

來源:

Path.Unix.cs

傳回值，指出所指定字元範圍所表示的檔案路徑是否包含根目錄。

public:
 static bool IsPathRooted(ReadOnlySpan<char> path);

public static bool IsPathRooted (ReadOnlySpan<char> path);

static member IsPathRooted : ReadOnlySpan<char> -> bool

Public Shared Function IsPathRooted (path As ReadOnlySpan(Of Char)) As Boolean

參數

path

ReadOnlySpan<Char>

要測試的路徑。

傳回

Boolean

如果 path 包含根目錄，則為 true；否則為 false。

另請參閱

• Windows 系統上的檔案路徑格式