DirectoryInfo.Exists Egenskap

Definition

Namnområde:
System.IO
Sammansättningar:
mscorlib.dll, System.IO.FileSystem.dll
Sammansättningar:
netstandard.dll, System.Runtime.dll
Sammansättningar:
netstandard.dll, System.IO.FileSystem.dll
Sammansättningar:
netstandard.dll, System.IO.FileSystem.dll, System.Runtime.dll
Sammansättning:
System.IO.FileSystem.dll
Sammansättning:
mscorlib.dll
Sammansättning:
netstandard.dll
Källa:
DirectoryInfo.cs
Källa:
DirectoryInfo.cs
Källa:
DirectoryInfo.cs
Källa:
DirectoryInfo.cs

Hämtar ett värde som anger om katalogen finns.

public:
 virtual property bool Exists { bool get(); };
public override bool Exists { get; }
member this.Exists : bool
Public Overrides ReadOnly Property Exists As Boolean

Egenskapsvärde

Boolean

trueom katalogen finns; annars . false

Exempel

I följande exempel visas en användning av Exists egenskapen i samband med kopiering av en källkatalog till en målkatalog.

using System;
using System.IO;

namespace DirectoryInfoCS2
{
    class Class1
    {
        // Copy a source directory to a target directory.
        static public void CopyDirectory(string SourceDirectory, string TargetDirectory)
        {
            DirectoryInfo	source = new DirectoryInfo(SourceDirectory);
            DirectoryInfo	target = new DirectoryInfo(TargetDirectory);
            
            //Determine whether the source directory exists.
            if(!source.Exists)
                return;
            if(!target.Exists)
                target.Create();
            
            //Copy files.
            FileInfo[] sourceFiles = source.GetFiles();	
            for(int i = 0; i < sourceFiles.Length; ++i)
                File.Copy(sourceFiles[i].FullName, target.FullName + "\\" + sourceFiles[i].Name,true);
            
            //Copy directories.
            DirectoryInfo[] sourceDirectories = source.GetDirectories();	
            for(int j = 0; j < sourceDirectories.Length; ++j)
                CopyDirectory(sourceDirectories[j].FullName,target.FullName +"\\" + sourceDirectories[j].Name);
        }

        static void Main(string[] args)
        {
            CopyDirectory("D:\\Tools","D:\\NewTools");
        }
    }
}

open System.IO

// Copy a source directory to a target directory.
let rec copyDirectory sourceDirectory targetDirectory =
    let source = DirectoryInfo sourceDirectory
    let target = DirectoryInfo targetDirectory
    
    //Determine whether the source directory exists.
    if source.Exists then
        if target.Exists then
            target.Create()
        
        //Copy files.
        let sourceFiles = source.GetFiles()
        for file in sourceFiles do
            File.Copy(file.FullName, target.FullName + "\\" + file.Name,true)
        
        //Copy directories.
        let sourceDirectories = source.GetDirectories()
        for dir in sourceDirectories do
            copyDirectory dir.FullName (target.FullName + "\\" + dir.Name)

copyDirectory "D:\\Tools" "D:\\NewTools"

Imports System.IO

Module Module1
    Public Sub CopyDirectory(ByVal SourceDirectory As String, ByVal TargetDirectory As String)
        Dim source As DirectoryInfo = New DirectoryInfo(SourceDirectory)
        Dim target As DirectoryInfo = New DirectoryInfo(TargetDirectory)

        'Determine whether the source directory exists.
        If (source.Exists = False) Then
            Return
        End If
        If (target.Exists = False) Then
            target.Create()
        End If

        'Copy files.
        Dim sourceFiles As FileInfo() = source.GetFiles()
        Dim i, j As Integer
        For i = 0 To sourceFiles.Length - 1
            File.Copy(sourceFiles(i).FullName, target.FullName + "\\" + sourceFiles(i).Name, True)
        Next i

        'Copy directories.
        Dim sourceDirectories As DirectoryInfo() = source.GetDirectories()
        For j = 0 To sourceDirectories.Length - 1
            CopyDirectory(sourceDirectories(j).FullName, target.FullName + "\\" + sourceDirectories(j).Name)
        Next j
        source = Nothing
        target = Nothing
    End Sub
    Sub Main()
        CopyDirectory("D:\\Tools", "D:\\NewTools")
    End Sub
End Module

Kommentarer

Egenskapen Exists returnerar false om något fel inträffar när du försöker avgöra om den angivna filen finns. Detta kan inträffa i situationer som skapar undantag som att skicka ett filnamn med ogiltiga tecken eller för många tecken, en disk som misslyckas eller saknas eller om anroparen inte har behörighet att läsa filen.

Gäller för

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