多线程与异步机制-优快云博客

本文介绍了在计算密集型任务中使用多线程技术，以及在IO密集型任务中运用异步机制的方法。通过具体的C#代码示例，展示了如何实现这两种技术，包括创建新的线程来执行特定任务以及通过异步方式获取网页内容。

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);