FileStream.BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) 方法

定義

開始非同步的讀取作業。 請考慮改用 ReadAsync(Byte[], Int32, Int32, CancellationToken)

public:
 override IAsyncResult ^ BeginRead(cli::array <System::Byte> ^ array, int offset, int numBytes, AsyncCallback ^ callback, System::Object ^ state);
public:
 override IAsyncResult ^ BeginRead(cli::array <System::Byte> ^ buffer, int offset, int count, AsyncCallback ^ callback, System::Object ^ state);
public:
 override IAsyncResult ^ BeginRead(cli::array <System::Byte> ^ array, int offset, int numBytes, AsyncCallback ^ userCallback, System::Object ^ stateObject);
public override IAsyncResult BeginRead (byte[] array, int offset, int numBytes, AsyncCallback? callback, object? state);
public override IAsyncResult BeginRead (byte[] buffer, int offset, int count, AsyncCallback? callback, object? state);
public override IAsyncResult BeginRead (byte[] buffer, int offset, int count, AsyncCallback callback, object state);
public override IAsyncResult BeginRead (byte[] array, int offset, int numBytes, AsyncCallback callback, object state);
public override IAsyncResult BeginRead (byte[] array, int offset, int numBytes, AsyncCallback callback, object? state);
public override IAsyncResult BeginRead (byte[] array, int offset, int numBytes, AsyncCallback userCallback, object stateObject);
override this.BeginRead : byte[] * int * int * AsyncCallback * obj -> IAsyncResult
override this.BeginRead : byte[] * int * int * AsyncCallback * obj -> IAsyncResult
override this.BeginRead : byte[] * int * int * AsyncCallback * obj -> IAsyncResult
Public Overrides Function BeginRead (array As Byte(), offset As Integer, numBytes As Integer, callback As AsyncCallback, state As Object) As IAsyncResult
Public Overrides Function BeginRead (buffer As Byte(), offset As Integer, count As Integer, callback As AsyncCallback, state As Object) As IAsyncResult
Public Overrides Function BeginRead (array As Byte(), offset As Integer, numBytes As Integer, userCallback As AsyncCallback, stateObject As Object) As IAsyncResult

參數

arraybuffer
Byte[]

要讀取資料的緩衝區。

offset
Int32

array 中要開始讀取的位元組位移。

numBytescount
Int32

要讀取的最大位元組數。

callbackuserCallback
AsyncCallback

在非同步讀取作業完成時所呼叫的方法。

statestateObject
Object

使用者所提供的物件,其可以從其他要求中區分出這個特定非同步讀取的要求。

傳回

IAsyncResult

物件,參考非同步讀取。

例外狀況

陣列長度減去 offset 會小於 numBytes

arraynull

offsetnumBytes 為負。

在超過檔案結尾處嘗試了非同步讀取。

適用於