NetworkStream.Write立即返回 - 如何判断它何时完成数据发送？

socket.SendBufferSize = buffer.Length;
networkStream.Write(buffer, 0, buffer.Length);

while (socket.Poll(1000, SelectMode.SelectWrite))
{
    if (socket.Available == 0)
    {
        // 数据已经被完全发送
        break;
    }
}

using System.Net.Sockets;

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
SocketAsyncEventArgs socketAsyncEventArgs = new SocketAsyncEventArgs();
socketAsyncEventArgs.SetBuffer(buffer, 0, buffer.Length);

socket.Connect(remoteEndPoint);
socket.SendAsync(socketAsyncEventArgs);

socketAsyncEventArgs.Completed += (sender, e) =>
{
    if (e.SocketError == SocketError.Success)
    {
        // 数据已经被完全发送
    }
};