InternalBufferOverflowException 類別

定義

命名空間:

System.IO

組件:

System.IO.FileSystem.Watcher.dll

來源:

InternalBufferOverflowException.cs

內部緩衝區溢位時，所擲回的例外狀況。

public ref class InternalBufferOverflowException : SystemException

public class InternalBufferOverflowException : SystemException

type InternalBufferOverflowException = class
    inherit SystemException

Public Class InternalBufferOverflowException
Inherits SystemException

繼承

Object

Exception

SystemException

InternalBufferOverflowException

範例

下列範例示範如何建立 FileSystemWatcher，以監視磁碟驅動器上 (建立、刪除、重新命名、變更) 的檔案變更。 此範例也會示範如何正確接收錯誤通知。

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

FileSystemWatcher在 中，當您收到檔案變更的通知時，系統會將這些變更儲存在元件建立的緩衝區中，並傳遞至應用程式程序設計介面 (API) 。 如果短時間內有許多變更，緩衝區可能會輕易溢位，導致擲回例外狀況，這基本上會遺失所有變更。 若要讓緩衝區無法溢位，請使用 FileSystemWatcher.NotifyFilter 和 FileSystemWatcher.IncludeSubdirectories 屬性來篩選出不必要的變更通知。 您也可以透過 FileSystemWatcher.InternalBufferSize 屬性增加內部緩衝區的大小。 不過，增加緩衝區的大小很昂貴，因此盡可能讓緩衝區保持小。

建構函式

InternalBufferOverflowException()	初始化 InternalBufferOverflowException 類別預設的新執行個體。
InternalBufferOverflowException(SerializationInfo, StreamingContext)	已淘汰. 初始化 InternalBufferOverflowException 類別的空白新執行個體，這個執行個體可序列化，並使用指定的 SerializationInfo 和 StreamingContext 物件。
InternalBufferOverflowException(String)	使用指定要顯示的錯誤訊息來初始化 InternalBufferOverflowException 類別的新執行個體。
InternalBufferOverflowException(String, Exception)	使用指定要顯示的訊息和指定產生的內部例外狀況，初始化 InternalBufferOverflowException 類別的新執行個體。

屬性

Data	取得鍵值組的集合，這些鍵值組會提供關於例外狀況的其他使用者定義資訊。 (繼承來源 Exception)
HelpLink	取得或設定與這個例外狀況相關聯的說明檔連結。 (繼承來源 Exception)
HResult	取得或設定 HRESULT，它是指派給特定例外狀況的編碼數值。 (繼承來源 Exception)
InnerException	取得造成目前例外狀況的 Exception 執行個體。 (繼承來源 Exception)
Message	取得描述目前例外狀況的訊息。 (繼承來源 Exception)
Source	取得或設定造成錯誤的應用程式或物件的名稱。 (繼承來源 Exception)
StackTrace	取得呼叫堆疊上即時運算框架的字串表示。 (繼承來源 Exception)
TargetSite	取得擲回目前例外狀況的方法。 (繼承來源 Exception)

方法

Equals(Object)	判斷指定的物件是否等於目前的物件。 (繼承來源 Object)
GetBaseException()	在衍生類別中覆寫時，傳回一或多個後續的例外狀況的根本原因 Exception。 (繼承來源 Exception)
GetHashCode()	做為預設雜湊函式。 (繼承來源 Object)
GetObjectData(SerializationInfo, StreamingContext)	已淘汰. 在衍生類別中覆寫時，使用例外狀況的資訊設定 SerializationInfo。 (繼承來源 Exception)
GetType()	取得目前執行個體的執行階段類型。 (繼承來源 Exception)
MemberwiseClone()	建立目前 Object 的淺層複製。 (繼承來源 Object)
ToString()	建立並傳回目前例外狀況的字串表示。 (繼承來源 Exception)

事件

SerializeObjectState

已淘汰. 當例外狀況序列化，以建立包含例外狀況相關序列化資料的例外狀況狀態物件時，就會發生此事件。 (繼承來源 Exception)

另請參閱

• FileSystemEventArgs
• FileSystemEventHandler
• FileSystemWatcher
• IncludeSubdirectories
• InternalBufferSize
• NotifyFilter
• NotifyFilters
• RenamedEventArgs
• RenamedEventHandler
• WaitForChangedResult
• WatcherChangeTypes