FileSystemWatcher 构造函数

参考

定义

命名空间:: System.IO

程序集:: System.IO.FileSystem.Watcher.dll

程序集:: System.dll

程序集:: netstandard.dll

重要

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初始化 FileSystemWatcher 类的新实例。

重载

FileSystemWatcher()	初始化 FileSystemWatcher 类的新实例。
FileSystemWatcher(String)	在给定要监视的指定目录的情况下，初始化 FileSystemWatcher 类的新实例。
FileSystemWatcher(String, String)	在给定要监视的指定目录和文件类型的情况下，初始化 FileSystemWatcher 类的新实例。

FileSystemWatcher()

Source:: FileSystemWatcher.cs

Source:: FileSystemWatcher.cs

Source:: FileSystemWatcher.cs

初始化 FileSystemWatcher 类的新实例。

public:
 FileSystemWatcher();

public FileSystemWatcher ();

Public Sub New ()

示例

以下示例创建一个 FileSystemWatcher 对象，用于watch运行时指定的目录。对象FileSystemWatcher监视和LastAccess时间的变化LastWrite，以及目录中文本文件的创建、删除或重命名。如果文件已更改、创建或删除，则该文件的路径将显示在控制台中。重命名文件时，控制台将显示新旧路径。

此示例使用 System.Diagnostics 和 System.IO 命名空间。

#include "pch.h"

using namespace System;
using namespace System::IO;

class MyClassCPP
{
public:

    int static Run()
    {
        FileSystemWatcher^ watcher = gcnew FileSystemWatcher("C:\\path\\to\\folder");

        watcher->NotifyFilter = static_cast<NotifyFilters>(NotifyFilters::Attributes
                                                         | NotifyFilters::CreationTime
                                                         | NotifyFilters::DirectoryName
                                                         | NotifyFilters::FileName
                                                         | NotifyFilters::LastAccess
                                                         | NotifyFilters::LastWrite
                                                         | NotifyFilters::Security
                                                         | NotifyFilters::Size);

        watcher->Changed += gcnew FileSystemEventHandler(MyClassCPP::OnChanged);
        watcher->Created += gcnew FileSystemEventHandler(MyClassCPP::OnCreated);
        watcher->Deleted += gcnew FileSystemEventHandler(MyClassCPP::OnDeleted);
        watcher->Renamed += gcnew RenamedEventHandler(MyClassCPP::OnRenamed);
        watcher->Error   += gcnew ErrorEventHandler(MyClassCPP::OnError);

        watcher->Filter = "*.txt";
        watcher->IncludeSubdirectories = true;
        watcher->EnableRaisingEvents = true;

        Console::WriteLine("Press enter to exit.");
        Console::ReadLine();

        return 0;
    }

private:

    static void OnChanged(Object^ sender, FileSystemEventArgs^ e)
    {
        if (e->ChangeType != WatcherChangeTypes::Changed)
        {
            return;
        }
        Console::WriteLine("Changed: {0}", e->FullPath);
    }

    static void OnCreated(Object^ sender, FileSystemEventArgs^ e)
    {
        Console::WriteLine("Created: {0}", e->FullPath);
    }

    static void OnDeleted(Object^ sender, FileSystemEventArgs^ e)
    {
        Console::WriteLine("Deleted: {0}", e->FullPath);
    }

    static void OnRenamed(Object^ sender, RenamedEventArgs^ e)
    {
        Console::WriteLine("Renamed:");
        Console::WriteLine("    Old: {0}", e->OldFullPath);
        Console::WriteLine("    New: {0}", e->FullPath);
    }

    static void OnError(Object^ sender, ErrorEventArgs^ e)
    {
        PrintException(e->GetException());
    }

    static void PrintException(Exception^ ex)
    {
        if (ex != nullptr)
        {
            Console::WriteLine("Message: {0}", ex->Message);
            Console::WriteLine("Stacktrace:");
            Console::WriteLine(ex->StackTrace);
            Console::WriteLine();
            PrintException(ex->InnerException);
        }
    }
};


int main()
{
    MyClassCPP::Run();
}

using System;
using System.IO;

namespace MyNamespace
{
    class MyClassCS
    {
        static void Main()
        {
            using var watcher = new FileSystemWatcher(@"C:\path\to\folder");

            watcher.NotifyFilter = NotifyFilters.Attributes
                                 | NotifyFilters.CreationTime
                                 | NotifyFilters.DirectoryName
                                 | NotifyFilters.FileName
                                 | NotifyFilters.LastAccess
                                 | NotifyFilters.LastWrite
                                 | NotifyFilters.Security
                                 | NotifyFilters.Size;

            watcher.Changed += OnChanged;
            watcher.Created += OnCreated;
            watcher.Deleted += OnDeleted;
            watcher.Renamed += OnRenamed;
            watcher.Error += OnError;

            watcher.Filter = "*.txt";
            watcher.IncludeSubdirectories = true;
            watcher.EnableRaisingEvents = true;

            Console.WriteLine("Press enter to exit.");
            Console.ReadLine();
        }

        private static void OnChanged(object sender, FileSystemEventArgs e)
        {
            if (e.ChangeType != WatcherChangeTypes.Changed)
            {
                return;
            }
            Console.WriteLine($"Changed: {e.FullPath}");
        }

        private static void OnCreated(object sender, FileSystemEventArgs e)
        {
            string value = $"Created: {e.FullPath}";
            Console.WriteLine(value);
        }

        private static void OnDeleted(object sender, FileSystemEventArgs e) =>
            Console.WriteLine($"Deleted: {e.FullPath}");

        private static void OnRenamed(object sender, RenamedEventArgs e)
        {
            Console.WriteLine($"Renamed:");
            Console.WriteLine($"    Old: {e.OldFullPath}");
            Console.WriteLine($"    New: {e.FullPath}");
        }

        private static void OnError(object sender, ErrorEventArgs e) =>
            PrintException(e.GetException());

        private static void PrintException(Exception? ex)
        {
            if (ex != null)
            {
                Console.WriteLine($"Message: {ex.Message}");
                Console.WriteLine("Stacktrace:");
                Console.WriteLine(ex.StackTrace);
                Console.WriteLine();
                PrintException(ex.InnerException);
            }
        }
    }
}

Imports System.IO

Namespace MyNamespace

    Class MyClassVB

        Shared Sub Main()
            Using watcher = New FileSystemWatcher("C:\path\to\folder")
                watcher.NotifyFilter = NotifyFilters.Attributes Or
                                       NotifyFilters.CreationTime Or
                                       NotifyFilters.DirectoryName Or
                                       NotifyFilters.FileName Or
                                       NotifyFilters.LastAccess Or
                                       NotifyFilters.LastWrite Or
                                       NotifyFilters.Security Or
                                       NotifyFilters.Size

                AddHandler watcher.Changed, AddressOf OnChanged
                AddHandler watcher.Created, AddressOf OnCreated
                AddHandler watcher.Deleted, AddressOf OnDeleted
                AddHandler watcher.Renamed, AddressOf OnRenamed
                AddHandler watcher.Error, AddressOf OnError

                watcher.Filter = "*.txt"
                watcher.IncludeSubdirectories = True
                watcher.EnableRaisingEvents = True

                Console.WriteLine("Press enter to exit.")
                Console.ReadLine()
            End Using
        End Sub

        Private Shared Sub OnChanged(sender As Object, e As FileSystemEventArgs)
            If e.ChangeType <> WatcherChangeTypes.Changed Then
                Return
            End If
            Console.WriteLine($"Changed: {e.FullPath}")
        End Sub

        Private Shared Sub OnCreated(sender As Object, e As FileSystemEventArgs)
            Dim value As String = $"Created: {e.FullPath}"
            Console.WriteLine(value)
        End Sub

        Private Shared Sub OnDeleted(sender As Object, e As FileSystemEventArgs)
            Console.WriteLine($"Deleted: {e.FullPath}")
        End Sub

        Private Shared Sub OnRenamed(sender As Object, e As RenamedEventArgs)
            Console.WriteLine($"Renamed:")
            Console.WriteLine($"    Old: {e.OldFullPath}")
            Console.WriteLine($"    New: {e.FullPath}")
        End Sub

        Private Shared Sub OnError(sender As Object, e As ErrorEventArgs)
            PrintException(e.GetException())
        End Sub

        Private Shared Sub PrintException(ex As Exception)
            If ex IsNot Nothing Then
                Console.WriteLine($"Message: {ex.Message}")
                Console.WriteLine("Stacktrace:")
                Console.WriteLine(ex.StackTrace)
                Console.WriteLine()
                PrintException(ex.InnerException)
            End If
        End Sub

    End Class

End Namespace

注解

不能watch没有 Windows NT 或 Windows 2000 的远程计算机。无法从 Windows NT 4.0 计算机watch远程 Windows NT 4.0 计算机。

下表显示了实例 FileSystemWatcher的初始属性值。

属性	初始值
NotifyFilter	、`FileName`、和的`LastWrite`按位 OR 组合`DirectoryName`
EnableRaisingEvents	`false`
Filter	“.” (监视所有文件。)
IncludeSubdirectories	`false`
InternalBufferSize	8192
Path	空字符串 (“”)

注意

在设置并且为 true之前Path，EnableRaisingEvents组件不会watch指定的目录。

另请参阅

适用于

FileSystemWatcher(String)

Source:: FileSystemWatcher.cs

Source:: FileSystemWatcher.cs

Source:: FileSystemWatcher.cs

在给定要监视的指定目录的情况下，初始化 FileSystemWatcher 类的新实例。

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

public FileSystemWatcher (string path);

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

Public Sub New (path As String)

参数

path: String

要监视的目录，以标准表示法或通用命名约定 (UNC) 表示法表示。

例外

ArgumentNullException

path 参数为 null。

ArgumentException

path 参数为空字符串 ("")。

- 或 -

通过 path 参数指定的路径不存在。

PathTooLongException

path 过长。

注解

注意

在设置并且为 true之前Path，EnableRaisingEvents组件不会watch指定的目录。

该组件可以在个人计算机、网络驱动器或远程计算机上watch文件。

不能watch没有 Windows NT 或 Windows 2000 的远程计算机。无法从 Windows NT 4.0 计算机watch远程 Windows NT 4.0 计算机。默认情况下，属性Filter设置为watch所有文件。

另请参阅

适用于

FileSystemWatcher(String, String)

Source:: FileSystemWatcher.cs

Source:: FileSystemWatcher.cs

Source:: FileSystemWatcher.cs

在给定要监视的指定目录和文件类型的情况下，初始化 FileSystemWatcher 类的新实例。

public:
 FileSystemWatcher(System::String ^ path, System::String ^ filter);

public FileSystemWatcher (string path, string filter);

new System.IO.FileSystemWatcher : string * string -> System.IO.FileSystemWatcher

Public Sub New (path As String, filter As String)

参数

path: String

要监视的目录，以标准表示法或通用命名约定 (UNC) 表示法表示。

filter: String

要监视的文件的类型。例如，“*.txt”监视所有文本文件的更改。

例外

ArgumentNullException

path 参数为 null。

- 或 -

filter 参数为 null。

ArgumentException

path 参数为空字符串 ("")。

- 或 -

通过 path 参数指定的路径不存在。

PathTooLongException

path 过长。

注解

注意

在设置并且为 true之前Path，EnableRaisingEvents组件不会watch指定的目录。

该组件可以在个人计算机、网络驱动器或远程计算机上watch文件。

不能watch没有 Windows NT 或 Windows 2000 的远程计算机。无法从 Windows NT 4.0 计算机watch远程 Windows NT 4.0 计算机。

另请参阅

适用于

通过

FileSystemWatcher 构造函数

定义

重载

FileSystemWatcher()

示例

注解

另请参阅

适用于

FileSystemWatcher(String)

参数

例外

注解

另请参阅

适用于

FileSystemWatcher(String, String)

参数

例外

注解

另请参阅

适用于

其他资源