Android技术精髓-Timing Activity
Timing Activity
顾名思义,在activity中实时通过线程通信显示当前时间,也是主要用到线程通信的知识,
package com.example.text_1;
import java.util.Calendar;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.widget.TextView;
public class TimeingActivity extends Activity {
TextView mClock;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mClock = new TextView(this);
setContentView(mClock);
}
private Handler mHandler = new Handler();
private Runnable timerTask = new Runnable() {
@Override
public void run() {
Calendar now = Calendar.getInstance();
mClock.setText(String.format("%02d:%02d:%02d",
now.get(Calendar.HOUR), now.get(Calendar.MINUTE),
now.get(Calendar.SECOND)));
mHandler.postDelayed(timerTask, 1000);
}
};
@Override
public void onResume() {
super.onResume();
mHandler.post(timerTask);
}
@Override
public void onPause() {
super.onPause();
mHandler.removeCallbacks(timerTask);
}
}
运行结果,实时显示目前时间。
当然的,你也可以实时显示任何变化的东西,时间、倒计时、等等。
关于多线程之Handler 可以看下之前这篇博客:http://blog.csdn.net/zhangtengyuan23/article/details/8862039
Calendar