InternalBufferOverflowException Classe

Definição

A exceção gerada quando o buffer interno estoura.The exception thrown when the internal buffer overflows.

public ref class InternalBufferOverflowException : SystemException
[System.Serializable]
public class InternalBufferOverflowException : SystemException
type InternalBufferOverflowException = class
    inherit SystemException
Public Class InternalBufferOverflowException
Inherits SystemException
Herança
InternalBufferOverflowException
Atributos

Exemplos

O exemplo a seguir mostra como criar um FileSystemWatcher para monitorar alterações de arquivo (cria, exclui, renomeia, alterações) que ocorrem em uma unidade de disco.The following example shows how to create a FileSystemWatcher to monitor file changes (creates, deletes, renames, changes) occurring on a disk drive. O exemplo também mostra como receber notificações de erro corretamente.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

Comentários

Em um FileSystemWatcher, quando você é notificado sobre alterações de arquivo, o sistema armazena essas alterações em um buffer que o componente cria e passa para as APIs (interfaces de programação de aplicativo).In a FileSystemWatcher, when you are notified of file changes, the system stores those changes in a buffer the component creates and passes to the Application Programming Interfaces (APIs). Se houver muitas alterações em um curto período de tempo, o buffer poderá ser facilmente estouro, resultando em uma exceção sendo gerada, o que, basicamente, perderá todas as alterações.If there are many changes in a short time, the buffer can easily overflow, resulting in an exception being thrown, which essentially loses all changes. Para manter o buffer do estouro, use as FileSystemWatcher.NotifyFilter Propriedades e FileSystemWatcher.IncludeSubdirectories para filtrar suas notificações de alteração indesejadas.To keep the buffer from overflowing, use the FileSystemWatcher.NotifyFilter and FileSystemWatcher.IncludeSubdirectories properties to filter out your unwanted change notifications. Você também pode aumentar o tamanho do buffer interno por meio da propriedade FileSystemWatcher.InternalBufferSize.You can also increase the size of the internal buffer through the FileSystemWatcher.InternalBufferSize property. No entanto, aumentar o tamanho do buffer é caro, portanto, mantenha o buffer o mais pequeno possível.However, increasing the size of the buffer is expensive, so keep the buffer as small as possible.

Construtores

InternalBufferOverflowException()

Inicializa uma nova instância padrão da classe InternalBufferOverflowException.Initializes a new default instance of the InternalBufferOverflowException class.

InternalBufferOverflowException(SerializationInfo, StreamingContext)

Inicializa uma nova instância vazia da classe InternalBufferOverflowException que pode ser serializada usando os objetos SerializationInfo e StreamingContext especificados.Initializes a new, empty instance of the InternalBufferOverflowException class that is serializable using the specified SerializationInfo and StreamingContext objects.

InternalBufferOverflowException(String)

Inicializa uma nova instância da classe InternalBufferOverflowException com a mensagem de erro para exibição especificada.Initializes a new instance of the InternalBufferOverflowException class with the error message to be displayed specified.

InternalBufferOverflowException(String, Exception)

Inicializa uma nova instância da classe InternalBufferOverflowException com a mensagem a ser exibida e a exceção interna gerada especificada.Initializes a new instance of the InternalBufferOverflowException class with the message to be displayed and the generated inner exception specified.

Propriedades

Data

Obtém uma coleção de pares de chave/valor que fornecem informações adicionais definidas pelo usuário sobre a exceção.Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(Herdado de Exception)
HelpLink

Obtém ou define um link para o arquivo de ajuda associado a essa exceção.Gets or sets a link to the help file associated with this exception.

(Herdado de Exception)
HResult

Obtém ou define HRESULT, um valor numérico codificado que é atribuído a uma exceção específica.Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

(Herdado de Exception)
InnerException

Obtém a instância Exception que causou a exceção atual.Gets the Exception instance that caused the current exception.

(Herdado de Exception)
Message

Obtém uma mensagem que descreve a exceção atual.Gets a message that describes the current exception.

(Herdado de Exception)
Source

Obtém ou define o nome do aplicativo ou objeto que causa o erro.Gets or sets the name of the application or the object that causes the error.

(Herdado de Exception)
StackTrace

Obtém uma representação de cadeia de caracteres de quadros imediatos na pilha de chamadas.Gets a string representation of the immediate frames on the call stack.

(Herdado de Exception)
TargetSite

Obtém o método que gerou a exceção atual.Gets the method that throws the current exception.

(Herdado de Exception)

Métodos

Equals(Object)

Determina se o objeto especificado é igual ao objeto atual.Determines whether the specified object is equal to the current object.

(Herdado de Object)
GetBaseException()

Quando substituído em uma classe derivada, retorna a Exception que é a causa raiz de uma ou mais exceções subsequentes.When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

(Herdado de Exception)
GetHashCode()

Serve como a função de hash padrão.Serves as the default hash function.

(Herdado de Object)
GetObjectData(SerializationInfo, StreamingContext)

Quando substituído em uma classe derivada, define o SerializationInfo com informações sobre a exceção.When overridden in a derived class, sets the SerializationInfo with information about the exception.

(Herdado de Exception)
GetType()

Obtém o tipo de tempo de execução da instância atual.Gets the runtime type of the current instance.

(Herdado de Exception)
MemberwiseClone()

Cria uma cópia superficial do Object atual.Creates a shallow copy of the current Object.

(Herdado de Object)
ToString()

Cria e retorna uma representação de cadeia de caracteres da exceção atual.Creates and returns a string representation of the current exception.

(Herdado de Exception)

Eventos

SerializeObjectState

Ocorre quando uma exceção é serializada para criar um objeto de estado de exceção que contém dados serializados sobre a exceção.Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.

(Herdado de Exception)

Aplica-se a

Veja também