“Timer”上的错误是“System.Windows.Forms.Timer”和“System.Threading.Timer”之间的引用不明确

我遇到过这个.NET编译时错误，如下所示：

'Timer' is an ambiguous reference between 
'System.Windows.Forms.Timer' and 'System.Threading.Timer' 
  

它是在我为时钟添加此代码块后发生的：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Threading;
using System.Security.Cryptography;


namespace SocketClient
{

    public partial class SocketClient : Form
    {
        System.Net.Sockets.TcpClient clientSocket = new System.Net.Sockets.TcpClient();
        NetworkStream serverStream = default(NetworkStream);
        string readData = null;


        public SocketClient()
        {
            InitializeComponent();
            Timer timer = new Timer();
            timer.Tick += new EventHandler(TimerOnTick);
            timer.Interval = 1000;
            timer.Start();
        }

         

        private void TimerOnTick(object sender, EventArgs ea)
        {
            Invalidate();
        }

        protected override void OnPaint(PaintEventArgs pea)
        {
            StringFormat strfmt = new StringFormat();
            strfmt.Alignment = StringAlignment.Far;
            strfmt.LineAlignment = StringAlignment.Far;

            pea.Graphics.DrawString(DateTime.Now.ToString("F"),
            Font, new SolidBrush(ForeColor),
            ClientRectangle, strfmt);

        }

        private void getMessage()
        {
            while (true)
            {
                serverStream = clientSocket.GetStream();
                int buffSize = 0;
                byte[] inStream = new byte[10025];
                buffSize = clientSocket.ReceiveBufferSize;
                serverStream.Read(inStream, 0, buffSize);
                string returndata = System.Text.Encoding.ASCII.GetString(inStream);
                readData = "" + returndata;
                msg();
            }
        }


        private void msg()
        {
            if (this.InvokeRequired)
                this.Invoke(new MethodInvoker(msg));
            else
                textDisplay.Text = textDisplay.Text + Environment.NewLine + " >> " + readData;
        }


        private void buttonConnect_Click(object sender, EventArgs e)
        {
      

            // show the message if no input is enter.
            if (string.IsNullOrEmpty(textName.Text) || string.IsNullOrEmpty(textPort.Text) || string.IsNullOrEmpty(textIP.Text))
            {
                MessageBox.Show("Please enter Name, IP Address & Port #");
            }
            else
            {
                //connect to the server if all 3 input is enter
                readData = "Conected to NYP Server ...";
                msg();
              
                clientSocket.Connect(textIP.Text, Convert.ToInt32(textPort.Text));
                serverStream = clientSocket.GetStream();

                byte[] outStream = System.Text.Encoding.ASCII.GetBytes(textName.Text + "$");
                serverStream.Write(outStream, 0, outStream.Length);
                serverStream.Flush();

                Thread ctThread = new Thread(getMessage);
                ctThread.Start();

             
            }
        }

        private void buttonSend_Click(object sender, EventArgs e)
        {
            // Show msg box if no server is connected
            if (serverStream == null)
            {
                MessageBox.Show("Please connect to a server first!");
                return;
            }

            // Send text
            byte[] outStream = System.Text.Encoding.ASCII.GetBytes(textSend.Text + "$");
            serverStream.Write(outStream, 0, outStream.Length);
            serverStream.Flush();

            // Clear text
            textSend.Text = "";

        }

        private void textDisplay_TextChanged(object sender, EventArgs e)
        {
            textDisplay.SelectionStart = textDisplay.Text.Length;
            textDisplay.ScrollToCaret();
            textDisplay.Refresh();
        }

        private void textSend_TextChanged(object sender, EventArgs e)
        {
            buttonSend.Enabled = !string.IsNullOrEmpty(textSend.Text);
        }
    }
}

如果我想避免这个错误，我有什么选择？

这里有多种选择：

• 使用别名：

  using UITimer = System.Windows.Forms.Timer;
  
  ...
  UITimer timer = new UITimer();
  

• 使用完全限定名称：

  System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();
  

• 使用命名空间别名：

  using WinForms = System.Windows.Forms;
  ...
  WinForms::Timer timer = new WinForms::Timer();
  

然而，我个人建议将用户界面代码与网络代码分开——此时它不太可能成为问题。

我还要指出的是，您当前正在从流中读取数据，而没有考虑返回值 - 这是一个坏主意，因为您不知道缓冲区实际上包含多少新数据。