ErrorEventArgs ErrorEventArgs ErrorEventArgs ErrorEventArgs Class

定義

提供 Error 事件的資料。Provides data for the Error event.

public ref class ErrorEventArgs : EventArgs
public class ErrorEventArgs : EventArgs
type ErrorEventArgs = class
    inherit EventArgs
Public Class ErrorEventArgs
Inherits EventArgs
繼承
ErrorEventArgsErrorEventArgsErrorEventArgsErrorEventArgs

範例

下列範例會建立的新實例, ErrorEventArgsException使用來初始化它。The following example creates a new instance of ErrorEventArgs and initializes it with an Exception. 然後, 範例會GetException呼叫來Exception取出並顯示錯誤訊息。Then the example calls GetException to retrieve the Exception and display the error message. 沒有與此程式碼相關聯的表單。There is no form associated with this code.

int main()
{
   
   // Creates an exception with an error message.
   Exception^ myException = gcnew Exception( "This is an exception test" );
   
   // Creates an ErrorEventArgs with the exception.
   ErrorEventArgs^ myErrorEventArgs = gcnew ErrorEventArgs( myException );
   
   // Extracts the exception from the ErrorEventArgs and display it.
   Exception^ myReturnedException = myErrorEventArgs->GetException();
   MessageBox::Show( String::Concat( "The returned exception is: ", myReturnedException->Message ) );
}

public static void Main(string[] args) {
    // Creates an exception with an error message.
    Exception myException= new Exception("This is an exception test");
 
    // Creates an ErrorEventArgs with the exception.
    ErrorEventArgs myErrorEventArgs = new ErrorEventArgs(myException);
 
    // Extracts the exception from the ErrorEventArgs and display it.
    Exception myReturnedException = myErrorEventArgs.GetException();
    MessageBox.Show("The returned exception is: " + myReturnedException.Message);
 }
    
Overloads Public Shared Sub Main(args() As String)
    ' Creates an exception with an error message.
    Dim myException As New Exception("This is an exception test")
    
    ' Creates an ErrorEventArgs with the exception.
    Dim myErrorEventArgs As New ErrorEventArgs(myException)
    
    ' Extracts the exception from the ErrorEventArgs and display it.
    Dim myReturnedException As Exception = myErrorEventArgs.GetException()
    MessageBox.Show(("The returned exception is: " & myReturnedException.Message))
End Sub 'Main

下列範例顯示如何建立 FileSystemWatcher, 以監視磁片磁碟機上發生的檔案變更 (建立、刪除、重新命名、變更)。The following example shows how to create a FileSystemWatcher to monitor file changes (creates, deletes, renames, changes) occurring on a disk drive. 此範例也會顯示如何正確地接收錯誤通知。The example also shows how to properly receive error notifications.

using System;
using System.IO;

class Program
{
    static void Main(string[] args)
    {
        //  Create a FileSystemWatcher to monitor all files on drive C.
        FileSystemWatcher fsw = new FileSystemWatcher("C:\\");

        //  Watch for changes in LastAccess and LastWrite times, and
        //  the renaming of files or directories. 
        fsw.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite
            | NotifyFilters.FileName |NotifyFilters.DirectoryName;

        //  Register a handler that gets called when a 
        //  file is created, changed, or deleted.
        fsw.Changed += new FileSystemEventHandler(OnChanged);

        fsw.Created += new FileSystemEventHandler(OnChanged);

        fsw.Deleted += new FileSystemEventHandler(OnChanged);

        //  Register a handler that gets called when a file is renamed.
        fsw.Renamed += new RenamedEventHandler(OnRenamed);

        //  Register a handler that gets called if the 
        //  FileSystemWatcher needs to report an error.
        fsw.Error += new ErrorEventHandler(OnError);

        //  Begin watching.
        fsw.EnableRaisingEvents = true;

        Console.WriteLine("Press \'Enter\' to quit the sample.");
        Console.ReadLine();


    }

    //  This method is called when a file is created, changed, or deleted.
    private static void OnChanged(object source, FileSystemEventArgs e)
    {
        //  Show that a file has been created, changed, or deleted.
        WatcherChangeTypes wct = e.ChangeType;
        Console.WriteLine("File {0} {1}", e.FullPath, wct.ToString());
    }

    //  This method is called when a file is renamed.
    private static void OnRenamed(object source, RenamedEventArgs e)
    {
        //  Show that a file has been renamed.
        WatcherChangeTypes wct = e.ChangeType;
        Console.WriteLine("File {0} {2} to {1}", e.OldFullPath, e.FullPath, wct.ToString());
    }

    //  This method is called when the FileSystemWatcher detects an error.
    private static void OnError(object source, ErrorEventArgs e)
    {
        //  Show that an error has been detected.
        Console.WriteLine("The FileSystemWatcher has detected an error");
        //  Give more information if the error is due to an internal buffer overflow.
        if (e.GetException().GetType() == typeof(InternalBufferOverflowException))
        {
            //  This can happen if Windows is reporting many file system events quickly 
            //  and internal buffer of the  FileSystemWatcher is not large enough to handle this
            //  rate of events. The InternalBufferOverflowException error informs the application
            //  that some of the file system events are being lost.
            Console.WriteLine(("The file system watcher experienced an internal buffer overflow: " + e.GetException().Message));
        }
    }

}
Imports System.IO

Module Module1
    Sub Main()
        ' Create a FileSystemWatcher to monitor all files on drive C.
        Dim fsw As New FileSystemWatcher("C:\")

        ' Watch for changes in LastAccess and LastWrite times, and
        ' the renaming of files or directories. 
        fsw.NotifyFilter = (NotifyFilters.LastAccess Or NotifyFilters.LastWrite _ 
            Or NotifyFilters.FileName Or NotifyFilters.DirectoryName)

        ' Register a handler that gets called when a 
        ' file is created, changed, or deleted.
        AddHandler fsw.Changed, New FileSystemEventHandler(AddressOf OnChanged)

        ' The commented line of code below is a shorthand of the above line.
        ' AddHandler fsw.Changed, AddressOf OnChanged

        ' NOTE: The shorthand version is used in the remainder of this code.
        ' FileSystemEventHandler
        AddHandler fsw.Created, AddressOf OnChanged 
        ' FileSystemEventHandler
        AddHandler fsw.Deleted, AddressOf OnChanged

        ' Register a handler that gets called when a file is renamed.
        ' RenamedEventHandler
        AddHandler fsw.Renamed, AddressOf OnRenamed

        ' Register a handler that gets called if the 
        ' FileSystemWatcher needs to report an error.
        ' ErrorEventHandler
        AddHandler fsw.Error, AddressOf OnError

        ' Begin watching.
        fsw.EnableRaisingEvents = True

        ' Wait for the user to quit the program.
        Console.WriteLine("Press 'Enter' to quit the sample.")
        Console.ReadLine()
    End Sub

    ' This method is called when a file is created, changed, or deleted.
    Private Sub OnChanged(ByVal source As Object, ByVal e As FileSystemEventArgs)

        ' Show that a file has been created, changed, or deleted.
        Dim wct As WatcherChangeTypes = e.ChangeType
        Console.WriteLine("File {0} {1}", e.FullPath, wct.ToString())
    End Sub

    ' This method is called when a file is renamed.
    Private Sub OnRenamed(ByVal source As Object, ByVal e As RenamedEventArgs)

        ' Show that a file has been renamed.
        Dim wct As WatcherChangeTypes = e.ChangeType
        Console.WriteLine("File {0} {2} to {1}", e.OldFullPath, e.FullPath, wct.ToString())
    End Sub

    ' This method is called when the FileSystemWatcher detects an error.
    Private Sub OnError(ByVal source As Object, ByVal e As ErrorEventArgs)

        ' Show that an error has been detected.
        Console.WriteLine("The FileSystemWatcher has detected an error")

        ' Give more information if the error is due to an internal buffer overflow.
        If TypeOf e.GetException Is InternalBufferOverflowException Then
            ' This can happen if Windows is reporting many file system events quickly 
            ' and internal buffer of the  FileSystemWatcher is not large enough to handle this
            ' rate of events. The InternalBufferOverflowException error informs the application
            ' that some of the file system events are being lost.
            Console.WriteLine( _
                "The file system watcher experienced an internal buffer overflow: " _
                + e.GetException.Message)
        End If
    End Sub
End Module

備註

ErrorEventArgsException 包含FileSystemWatcher.Error造成事件的。ErrorEventArgs contains the Exception that caused the FileSystemWatcher.Error event. 這個類別會提供GetException方法來取得例外狀況。This class provides the GetException method to retrieve the exception.

建構函式

ErrorEventArgs(Exception) ErrorEventArgs(Exception) ErrorEventArgs(Exception) ErrorEventArgs(Exception)

初始化 ErrorEventArgs 類別的新執行個體。Initializes a new instance of the ErrorEventArgs class.

方法

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

判斷指定的物件是否等於目前的物件。Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetException() GetException() GetException() GetException()

取得 Exception,表示發生的錯誤。Gets the Exception that represents the error that occurred.

GetHashCode() GetHashCode() GetHashCode() GetHashCode()

做為預設雜湊函式。Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

取得目前執行個體的 TypeGets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

建立目前 Object 的淺層複本 (Shallow Copy)。Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

傳回代表目前物件的字串。Returns a string that represents the current object.

(Inherited from Object)

適用於

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