InternalBufferOverflowException Class

Definition

Исключение, которое создается при переполнении внутреннего буфера.The exception thrown when the internal buffer overflows.

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

Examples

В следующем примере показано, как создать FileSystemWatcher для отслеживания изменений в файле (создание, удаление, переименование, изменение), происходящих на диске.The following example shows how to create a FileSystemWatcher to monitor file changes (creates, deletes, renames, changes) occurring on a disk drive. В примере также показано, как правильно получать уведомления об ошибках.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

Remarks

В FileSystemWatcherпри получении уведомления об изменениях файла система сохраняет эти изменения в буфере, который создается компонентом и передается в интерфейсы программирования приложений (API).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). Если в течение короткого промежутка времени произошло много изменений, буфер может легко переполниться, что приведет к возникновению исключения, которое, по сути, теряет все изменения.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. Чтобы предотвратить переполнение буфера, используйте свойства FileSystemWatcher.NotifyFilter и FileSystemWatcher.IncludeSubdirectories, чтобы отфильтровать ненужные уведомления об изменениях.To keep the buffer from overflowing, use the FileSystemWatcher.NotifyFilter and FileSystemWatcher.IncludeSubdirectories properties to filter out your unwanted change notifications. С помощью свойства FileSystemWatcher.InternalBufferSize можно также увеличить размер внутреннего буфера.You can also increase the size of the internal buffer through the FileSystemWatcher.InternalBufferSize property. Однако увеличение размера буфера занимает много ресурсов, поэтому буфер следует по возможности увеличивать как можно меньше.However, increasing the size of the buffer is expensive, so keep the buffer as small as possible.

Constructors

InternalBufferOverflowException()

Инициализирует новый экземпляр по умолчанию для класса InternalBufferOverflowException.Initializes a new default instance of the InternalBufferOverflowException class.

InternalBufferOverflowException(SerializationInfo, StreamingContext)

Инициализирует новый пустой экземпляр класса InternalBufferOverflowException, который может быть сериализован с помощью объектов SerializationInfo и StreamingContext.Initializes a new, empty instance of the InternalBufferOverflowException class that is serializable using the specified SerializationInfo and StreamingContext objects.

InternalBufferOverflowException(String)

Инициализирует новый экземпляр класса InternalBufferOverflowException с заданным сообщением об ошибке для отображения.Initializes a new instance of the InternalBufferOverflowException class with the error message to be displayed specified.

InternalBufferOverflowException(String, Exception)

Инициализирует новый экземпляр класса InternalBufferOverflowException с заданным сообщением для отображения и созданным внутренним исключением.Initializes a new instance of the InternalBufferOverflowException class with the message to be displayed and the generated inner exception specified.

Properties

Data

Возвращает коллекцию пар «ключ-значение», предоставляющую дополнительные сведения об исключении.Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(Inherited from Exception)
HelpLink

Получает или задает ссылку на файл справки, связанный с этим исключением.Gets or sets a link to the help file associated with this exception.

(Inherited from Exception)
HResult

Возвращает или задает HRESULT — кодированное числовое значение, присвоенное определенному исключению.Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

(Inherited from Exception)
InnerException

Возвращает экземпляр класса Exception, который вызвал текущее исключение.Gets the Exception instance that caused the current exception.

(Inherited from Exception)
Message

Возвращает сообщение, описывающее текущее исключение.Gets a message that describes the current exception.

(Inherited from Exception)
Source

Возвращает или задает имя приложения или объекта, вызывавшего ошибку.Gets or sets the name of the application or the object that causes the error.

(Inherited from Exception)
StackTrace

Получает строковое представление непосредственных кадров в стеке вызова.Gets a string representation of the immediate frames on the call stack.

(Inherited from Exception)
TargetSite

Возвращает метод, создавший текущее исключение.Gets the method that throws the current exception.

(Inherited from Exception)

Methods

Equals(Object)

Определяет, равен ли заданный объект текущему объекту.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetBaseException()

При переопределении в производном классе возвращает исключение Exception, которое является первопричиной одного или нескольких последующих исключений.When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

(Inherited from Exception)
GetHashCode()

Служит хэш-функцией по умолчанию.Serves as the default hash function.

(Inherited from Object)
GetObjectData(SerializationInfo, StreamingContext)

При переопределении в производном классе задает объект SerializationInfo со сведениями об исключении.When overridden in a derived class, sets the SerializationInfo with information about the exception.

(Inherited from Exception)
GetType()

Возвращает тип среды выполнения текущего экземпляра.Gets the runtime type of the current instance.

(Inherited from Exception)
MemberwiseClone()

Создает неполную копию текущего объекта Object.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString()

Создает и возвращает строковое представление текущего исключения.Creates and returns a string representation of the current exception.

(Inherited from Exception)

Events

SerializeObjectState

Возникает, когда исключение сериализовано для создания объекта состояния исключения, содержащего сериализованные данные об исключении.Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.

(Inherited from Exception)

Applies to

See also