當內部緩衝區已滿時,方法 BufferedStream.WriteByte(Byte) 不再執行隱含排清。 這項變更會讓 的BufferedStream.WriteByte行為與類別中的Write其他BufferedStream方法保持一致,例如 BufferedStream.Write(Byte[], Int32, Int32) 和 BufferedStream.WriteAsync(Byte[], Int32, Int32, CancellationToken),這些方法不會執行隱含排清。
推出的版本
.NET 10
先前的行為
先前,當 BufferedStream 的內部緩衝區已滿時,呼叫 WriteByte 會自動將緩衝區清空至底層資料流。 此行為與Write中的其他BufferedStream方法不一致。
下列範例示範先前的行為:
StreamWithFlush streamWithFlush = new();
BufferedStream bufferedStream = new(streamWithFlush, bufferSize: 4);
// Write 4 bytes to fill the buffer
bufferedStream.WriteByte(1);
bufferedStream.WriteByte(2);
bufferedStream.WriteByte(3);
bufferedStream.WriteByte(4); // In .NET 9 and earlier, this caused an implicit flush
class StreamWithFlush : MemoryStream
{
public override void Flush()
{
Console.WriteLine("Flush was called.");
base.Flush();
}
}
Module PreviousBehaviorExample
Sub Example()
Dim streamWithFlush As New StreamWithFlush()
Dim bufferedStream As New BufferedStream(streamWithFlush, bufferSize:=4)
' Write 4 bytes to fill the buffer
bufferedStream.WriteByte(1)
bufferedStream.WriteByte(2)
bufferedStream.WriteByte(3)
bufferedStream.WriteByte(4) ' In .NET 9 and earlier, this caused an implicit flush
End Sub
Class StreamWithFlush
Inherits MemoryStream
Public Overrides Sub Flush()
Console.WriteLine("Flush was called.")
MyBase.Flush()
End Sub
End Class
End Module
新行為
從 .NET 10 開始,當內部緩衝區已滿時,方法 WriteByte 不再執行隱含排清。 只有在明確呼叫BufferedStream.Flush()方法或BufferedStream被處置時,才會清空緩衝區。
破壞性變更的類型
此變更為行為變更。
變更的原因
BufferedStream.WriteByte(Byte) 函數的隱含刷新行為與 Write 類別中的其他方法,例如 BufferedStream 和 Write,不一致。 這種不一致可能會在使用對排清作業敏感的串流時,導致非預期的效能問題或非預期的副作用。 移除隱含的 flush 可以確保Write中的所有BufferedStream方法行為一致。
建議的動作
如果您的應用程式依賴於BufferedStream.WriteByte的隱含排清行為,請更新程式碼,以便在需要時明確呼叫Flush方法。 例如:
Before:
BufferedStream bufferedStream = new(new MemoryStream(), bufferSize: 4);
bufferedStream.WriteByte(1);
bufferedStream.WriteByte(2);
bufferedStream.WriteByte(3);
bufferedStream.WriteByte(4); // Implicit flush occurred here in .NET 9 and earlier
Dim bufferedStream As New BufferedStream(New MemoryStream(), bufferSize:=4)
bufferedStream.WriteByte(1)
bufferedStream.WriteByte(2)
bufferedStream.WriteByte(3)
bufferedStream.WriteByte(4) ' Implicit flush occurred here in .NET 9 and earlier
After:
BufferedStream bufferedStream = new(new MemoryStream(), bufferSize: 4);
bufferedStream.WriteByte(1);
bufferedStream.WriteByte(2);
bufferedStream.WriteByte(3);
bufferedStream.WriteByte(4);
bufferedStream.Flush(); // Explicit flush
Dim bufferedStream As New BufferedStream(New MemoryStream(), bufferSize:=4)
bufferedStream.WriteByte(1)
bufferedStream.WriteByte(2)
bufferedStream.WriteByte(3)
bufferedStream.WriteByte(4)
bufferedStream.Flush() ' Explicit flush