Android的Handler使用

Android的Handler使用

如何每隔一段时间进行一些操作呢，Handler就可以做到。 下面的Demo的功能为每隔3秒显示MyItems数组中的不同数据。

public class MainActivity extends Activity {
	private int count = 0;
	private static final String[] MyItems = {
    	"Here is a Item1", "Here is a Item2", "Here is a Item3", "Here is a Item4" };
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		Timer timer = new Timer();
		timer.scheduleAtFixedRate(new Newtask(), 10, 3000);
	}		
	private Handler hand = new Handler(){
		public void handleMessage(Message msg){
			switch(msg.what)
			{
			case 1:				
				Toast.makeText(MainActivity.this, MyItems[count], Toast.LENGTH_SHORT).show();
				if(count == 3)
					count = 0;
				else
					count++;
				break;
			}
		};
	};

	private class Newtask extends TimerTask
	{
		@Override
		public void run() {
			// TODO Auto-generated method stub
			Message msg = new Message();
			msg.what = 1;
			hand.sendMessage(msg);	
		}	
	}
}

 

下面的文章讲解的比较详细：

Android之Handler用法总结