FileSystemWatcher.EnableRaisingEvents 属性
定义
获取或设置一个值,该值指示是否启用此组件。Gets or sets a value indicating whether the component is enabled.
public:
property bool EnableRaisingEvents { bool get(); void set(bool value); };
public bool EnableRaisingEvents { get; set; }
[System.IO.IODescription("FSW_Enabled")]
public bool EnableRaisingEvents { get; set; }
[System.IO.IODescription("Flag to indicate if this instance is active")]
public bool EnableRaisingEvents { get; set; }
member this.EnableRaisingEvents : bool with get, set
[<System.IO.IODescription("FSW_Enabled")>]
member this.EnableRaisingEvents : bool with get, set
[<System.IO.IODescription("Flag to indicate if this instance is active")>]
member this.EnableRaisingEvents : bool with get, set
Public Property EnableRaisingEvents As Boolean
属性值
如果启用此组件,则为 true;否则为 false。true if the component is enabled; otherwise, false. 默认值为 false。The default is false. 如果要在 Visual Studio 2005 的设计器中使用该组件,则默认值为 true 。If you are using the component on a designer in Visual Studio 2005, the default is true.
- 属性
例外
FileSystemWatcher 对象已释放。The FileSystemWatcher object has been disposed.
当前操作系统不是 Microsoft Windows NT 或更高版本。The current operating system is not Microsoft Windows NT or later.
示例
下面的示例创建一个 FileSystemWatcher 来监视运行时指定的目录。The following example creates a FileSystemWatcher to watch the directory specified at run time. 组件设置为监视和时间中的更改 LastWrite LastAccess 、创建、删除或重命名目录中的文本文件。The component is set to watch for changes in LastWrite and LastAccess time, the creation, deletion, or renaming of text files in the directory. 如果更改、创建或删除了某个文件,则该文件的路径将打印到控制台。If a file is changed, created, or deleted, the path to the file prints to the console. 重命名文件后,旧路径和新路径将打印到控制台。When a file is renamed, the old and new paths print to the console.
#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
除非将设置为,否则组件将不会引发事件 EnableRaisingEvents true 。The component will not raise events unless you set EnableRaisingEvents to true.
备注
只有在 Path 设置了属性且该属性为之后,组件才会监视指定的目录 EnableRaisingEvents true 。The component will not watch the specified directory until the Path property has been set and EnableRaisingEvents is true.
WaitForChanged方法允许调用事件处理程序以响应文件更改,即使此属性设置为也是如此 false 。The WaitForChanged method allows event handlers to be invoked to respond to file changes even if this property is set to false.