Runnable

前文線程(Thread)展示了如何通過擴展線程(extends Thread)實現一個新類並重寫其的run()方法來創建一個線程.

現在來看看創建線程的另一種方法: 實現一個線程類(Thread class)的對象, 並在實現時提供一個Runnable對象.

main.xml跟前文線程(Thread)的一樣.

AndroidThread.java

package com.AndroidThread;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidThread extends Activity {

String strRunning = "-";
TextView tvMarkingrunning;
Button buttonNewThread, buttonStopRunning, buttonJoin, buttonGetState;

Thread myThread;
private boolean running = false;

   Handler myHandler = new Handler(){

 @Override
 public void handleMessage(Message msg) {
  // TODO Auto-generated method stub
  strRunning = rotateMarking(strRunning);
  tvMarkingrunning.setText("running: " + strRunning);
 }
   };
  
   private String rotateMarking(String marking){
    if (marking=="-"){
     return("\\");
    }
    else if (marking=="\\"){
     return("|");
    }
    else if (marking=="|"){
     return("/");
    }
    else{
     return("-");
    }
   }
  
   private void setButtonsEnable(boolean enableNewThread,
     boolean enableStopRunning,
     boolean enableJoin){
   
       buttonNewThread.setEnabled(enableNewThread);
       buttonStopRunning.setEnabled(enableStopRunning);
       buttonJoin.setEnabled(enableJoin);
   
   }
  
/** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
      
       tvMarkingrunning = (TextView)findViewById(R.id.markingrunning);
       buttonNewThread = (Button)findViewById(R.id.newthread);
       buttonStopRunning = (Button)findViewById(R.id.stoprunning);
       buttonJoin = (Button)findViewById(R.id.join);
       buttonGetState = (Button)findViewById(R.id.getstate);
      
       buttonNewThread.setOnClickListener(buttonNewThreadOnClickListener);
       buttonStopRunning.setOnClickListener(buttonStopRunningOnClickListener);
       buttonJoin.setOnClickListener(buttonJoinOnClickListener);
       buttonGetState.setOnClickListener(buttonGetStateOnClickListener);
      
       setButtonsEnable(true, false, false);
   }
  
   private Button.OnClickListener buttonGetStateOnClickListener =
    new Button.OnClickListener(){

  @Override
  public void onClick(View v) {
   // TODO Auto-generated method stub
   Toast.makeText(getBaseContext(), myThread.getState().toString(), Toast.LENGTH_LONG).show();
  }
   };
  
   private Button.OnClickListener buttonNewThreadOnClickListener =
    new Button.OnClickListener(){

  @Override
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
  
   myThread = new Thread(new Runnable(){

    public void run() {
     // TODO Auto-generated method stub
     while(running){
      try {
       Thread.sleep(500);
       myHandler.sendMessage(myHandler.obtainMessage());
      } catch (InterruptedException e) {
       // TODO Auto-generated catch block
       e.printStackTrace();
      }
     }
    }
      });
  
   setRunning(true);
   myThread.start();
   Toast.makeText(getBaseContext(), myThread.getState().toString(), Toast.LENGTH_LONG).show();
   setButtonsEnable(false, true, true);
  }
   };
  
   private void setRunning(boolean b){
 running = b;
}

   private Button.OnClickListener buttonStopRunningOnClickListener =
    new Button.OnClickListener(){

  @Override
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
   setRunning(false);
   Toast.makeText(getBaseContext(), myThread.getState().toString(), Toast.LENGTH_LONG).show();
   setButtonsEnable(true, false, false);
  }
   };
  
   private Button.OnClickListener buttonJoinOnClickListener =
    new Button.OnClickListener(){

  @Override
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
   boolean retry = true;
   setRunning(false);
   while(retry){
    try {
     myThread.join();
     retry = false;
    } catch (InterruptedException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
   Toast.makeText(getBaseContext(), myThread.getState().toString(), Toast.LENGTH_LONG).show();
   setButtonsEnable(true, false, false);

  }
   };
}

相關文章:
- 線程(Thread)
- 異步任務(AsyncTask)