android handler机制和Timer的使用

Timer主要用于创建每隔一段时间就执行的任务。

创建继承Task的任务类，也就是每段时间执行的任务。

private class MyTask extends TimerTask
	{
		@Override
		public void run() {
			Message msg = new Message();
			msg.what = 1;
			handler.sendMessage(msg);
		}
	}
}

Timer timer = new Timer();
timer.schedule(new MyTask(), 1, 2000);

方法接受参数。根据msg.what进行操作判断，进行相应的操作。

整体代码：

package com.example.androidtest;
import java.util.Timer;
import java.util.TimerTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {
	TextView show;
	@SuppressLint("HandlerLeak")
	Handler handler = new Handler()
	{
		@Override
		public void handleMessage(Message msg)
		{
			switch(msg.what)
			{
			case 1:
				show.setText("标题为：" + title);
				title ++;
				break;
			}
			super.handleMessage(msg);
		}
	};
	int title = 0;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		show = (TextView)findViewById(R.id.show);
		Timer timer = new Timer();
		timer.schedule(new MyTask(), 1, 2000);
	}
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
	private class MyTask extends TimerTask
	{
		@Override
		public void run() {
			Message msg = new Message();
			msg.what = 1;
			handler.sendMessage(msg);
		}
	}
}