关于多线程和异步

 

计算密集型工作，采用多线程。

IO密集型工作，采用异步机制。

 

/// <summary>
      /// 多线程 新开一个线程执行程序
      /// </summary>
      private void btnMutilthread_Click(object sender, EventArgs e)
      {
          var thread = new Thread(DoSomething);
          thread.Start();
      }

      public void DoSomething()
      {
          var request = HttpWebRequest.Create("http://www.cnblogs.com/jx270");
          var response = request.GetResponse();
          var stream = response.GetResponseStream();
          using (StreamReader reader = new StreamReader(stream))
          {
              var content = reader.ReadToEnd();
              //textBox1.Text = content;
              SetText(content);
          }
      }

      /// <summary>
      /// 异步执行程序 减少占有CPU (DMA中断方式)
      /// </summary>
      private void btnAsyc_Click(object sender, EventArgs e)
      {
          var request = HttpWebRequest.Create("http://www.cnblogs.com/jx270");
          request.BeginGetResponse(this.AsyncCallbackImp, request);
      }

      public void AsyncCallbackImp(IAsyncResult ar)
      {
          WebRequest request = ar.AsyncState as WebRequest;
          var response = request.EndGetResponse(ar);
          var stream = response.GetResponseStream();
          using (StreamReader reader = new StreamReader(stream))
          {
              var content = reader.ReadToEnd();
              //textBox1.Text = content;
              SetText(content);
          }
      }

      void SetText(string argText)
      {
          if (textBox1.InvokeRequired)
          {
              var callBack = new DelegateMethod(SetText);
              textBox1.Invoke(callBack, new[] { argText });
          }
          else
          {
              textBox1.Text = argText;
          }
      }

      delegate void DelegateMethod(string argText);