Android常用的3种定时刷新UI的方法和子线程能否刷新UI那些事

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import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
TextView text1,text2, text3;
Button button;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text1 = (TextView) findViewById(R.id.info1);
text2 = (TextView) findViewById(R.id.info2);
text3 = (TextView) findViewById(R.id.info3);
button = (Button)findViewById(R.id.button1);
//第一种刷新Timer，TimerTask
timer.schedule(new TimerTask() {
@Override
public void run() {
handler.sendEmptyMessage(0);
}
}, 0, 1000);//延时0秒后每隔1秒刷新一次。
//结束timer调用：
//timer.cancel();
//第二种mHandler.postDelayed(runnable, 1000);
mHandler.removeCallbacks(runnable);
mHandler.postDelayed(runnable, 1000);
//结束mHandler调用
//mHandler.removeCallbacks(runnable);
//第三种调用2次showHandler.sendMessageDelayed(message, 1000);形成循环。
startShowUI();
//取消startShowUI()的调用
//showHandler.removeMessages(0);
}
//第一种方法
Timer timer = new Timer();
private int temp1 = 0;
private Handler handler = new Handler(){
public void handleMessage(Message msg) {
text1.setText("count temp1 = " + temp1);
temp1++;
};
};
//第二种方法
private int temp2 = 0;
private Handler mHandler = new Handler();
private Runnable runnable = new Runnable() {
@Override
public void run() {
text2.setText("count temp2 = " + temp2);
temp2++;
mHandler.postDelayed(runnable, 1000);
}
};
//第三种方法
private Handler showHandler;
private int temp3 = 0;
private void startShowUI(){
showHandler = new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
text3.setText("count temp3 = " + temp3);
temp3++;
Message message = handler.obtainMessage(0);
showHandler.sendMessageDelayed(message, 1000);
}
};
Message message = handler.obtainMessage(0);
showHandler.sendMessageDelayed(message, 1000);
}
}

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