应为具有IAsyncResult BeginSend的方法

Question

嗨，我正在尝试创建一个水龙头包装器。ConnectTaskAsync很好，但是我在使用SendTaskAsync时遇到了一些问题。

public static Task ConnectTaskAsync(this Socket socket, EndPoint endpoint)
        {
            return Task.Factory.FromAsync(socket.BeginConnect, socket.EndConnect, endpoint, null);
        }

    public static Task<int> SendTaskAsync(this Socket socket, byte[] buffer, int offset, int size, SocketFlags flags)
    {
        return Task<int>.Factory.FromAsync(socket.BeginSend, buffer, offset, size, flags, socket.EndSend, null);
    }

我收到的错误是在BeginSend下面有一个红色下划线，并显示消息Expected a method with IAsyncResult BeginSend

我哪里错了？

Answer 1

您的FromAsync定义不正确。不幸的是，没有一个可以接受4个独立参数的overload of FromAsync (这对于BeginSend是必需的)，所以您需要use a different overload

public static Task<int> SendTaskAsync(this Socket socket, byte[] buffer, int offset, int size, SocketFlags flags)
{
    AsyncCallback nullOp = (i) => {};
    IAsyncResult result = socket.BeginSend(buffer, offset, size, flags, nullOp, socket);
    // Use overload that takes an IAsyncResult directly
    return Task.Factory.FromAsync(result, socket.EndSend);
}