FileStream.BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) 方法
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
開始異步讀取作業。 請考慮改用 ReadAsync(Byte[], Int32, Int32, CancellationToken)。
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 ^ 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[] 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[] 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 (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, 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[]
用來讀取資料的緩衝區。
- offset
- Int32
開始讀取的位元組偏移 array 。
- numBytescount
- Int32
最大可讀取的位元組數。
- callbackuserCallback
- AsyncCallback
非同步讀取操作完成後,將呼叫的方法。
- statestateObject
- Object
一個使用者提供的物件,用來區分此特定非同步讀取請求與其他請求。
傳回
一個參考非同步讀取的物件。
例外狀況
陣列長度減 offset 去 小於 numBytes。
array 是 null。
offset 或 numBytes 是陰性。
嘗試在檔案末尾以非同步讀取。