c# - 需要双冲吗？

Question

是否需要在刷新 StreamWriter 之后刷新 Stream？

public static async Task WriteStringAsync(this Stream stream, string messageString)
{
        var encoding = new UTF8Encoding(false); //no BOM
        using (var streamWriter = new StreamWriter(stream, encoding))
        {
            await streamWriter.WriteAsync(messageString);
            await streamWriter.FlushAsync();
        }
        await stream.FlushAsync(); //is this necessary?
}

Answer 1

根据 MSDN 文档，这可以被原谅为“只是确保”...

StreamWriter.Flush():

Clears all buffers for the current writer and causes any buffered data to be written to the underlying stream.

流.Flush():

When overridden in a derived class, clears all buffers for this stream and causes any buffered data to be written to the underlying device.

...但是，仔细查看 TypeDescriptor 中的代码会发现 StreamWriter.Flush()(我假设它的异步对应物 FlushAsync)是调用主函数的重载，传递两个指示 StreamWriter 的 bool 参数刷新 Stream 和 Unicode 编码器。因此，调用 StreamWriter.FlushAsync() 并结合 await 关键字以确保异步操作已完全发生，应该没问题。