FileSystemWatcher.EnableRaisingEvents 屬性
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
取得或設定數值，表示是否啟用元件。
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; }member this.EnableRaisingEvents : bool with get, set[<System.IO.IODescription("FSW_Enabled")>]
member this.EnableRaisingEvents : bool with get, setPublic Property EnableRaisingEvents As Boolean屬性值
如果啟用元件，則為 true；否則為 false。 預設為 false。 如果您在 Visual Studio 2005 中的設計工具上使用元件，則預設值為 true。
- 屬性
例外狀況
目前的作業系統不是 Microsoft Windows NT 或更新版本。
找不到在 Path 中指定的目錄。
Path 尚未設定或無效。
範例
下列範例會FileSystemWatcher建立 ，以 watch 運行時間指定的目錄。 元件會設定為 watch，以便LastWrite變更和LastAccess時間、建立、刪除或重新命名目錄中的文本檔。 如果檔案已變更、建立或刪除，則檔案的路徑會列印至主控台。 重新命名檔案時，舊路徑和新路徑會列印到主控台。
#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
備註
除非您將 設定 EnableRaisingEvents 為 true，否則元件不會引發事件。
注意
在設定 屬性且 為 true之前PathEnableRaisingEvents，元件不會 watch 指定的目錄。
方法 WaitForChanged 允許叫用事件處理程式來回應檔案變更，即使此屬性設定為 false也一樣。
