android handler机制和Timer采用

Timer主要用于创建一个任务来定期运行。

创建继承Task该任务等级。即任务每次跑。

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);

也能够直接使用线程简历耗时操作。这里也就做一个Timer和Thread的差别使用吧。

private class MyTread extends Thread
{
	int i = 0;
	@Override
	public void run()
	{
		while(true)
		{
			system.out.println();
			i++:
			try
			{
				sleep(1000);
			}
			catch(InterruptedException e)
			{
				e.printStackTrace();
			}
		}
	}
}

方法接受參数。依据msg.what进行操作推断，进行对应的操作。

总体代码：

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);
		}
	}
}