在学Handler

HandlerTest.java

public class HandlerTest extends Activity{
  private Button button ;
  private TextView view;
  private Handler handler;

  protected void onCreat(Bundle savedInstanceState){
     super.onCreate(savedInstanceState);
        setContentView(R.layout.testView);
    
      button = (Button) findViewById(R.id.btn);
      view = (TextView) findViewById(R.id.tv);
      handler = new myHandler();
      
      button.setOnClickListener(new btnListener());
      
  }
  
  class buttonListener implements View.OnClickListener{
    public void onClick(View v) {
            Thread thread = new networkThread();
            thread.start();
    }
  }
  
  
  class networkThread extends Thread{
    public void run(){
      
      System.out.println("network---->" + Thread.currentThread().getName());
      
      try {
                Thread.sleep(20);

            } catch (Exception e) {

                e.printStackTrace();
            }
            
            String s = "从网络当中读取数据";
      
            Message msg = handler.obtainMessage();
            msg.obj = s;
            handler.sendMessage(msg);
    }
  }
  
  
  class myHandler extends Handler{
    public void handleMessage(Message msg) {

            System.out.println("Handler----->" + Thread.currentThread().getName());
            
            String s = (String) msg.obj;
            
            view.setText(s);
    }
  }
  
  
  
  
  

}

testView.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}">


    <TextView
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="数据"
        />

    <Button
        android:id="@+id/btn"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="发送数据"
        />
</LinearLayout>