本文实例讲述了Android编程之基于Log演示一个activity生命周期。分享给大家供大家参考,具体如下:
利用Android的Log 演示一个activity的生命周期
代码:
//DemoActivity.java
package uni.activity;
/*
@author octobershiner
2011 7 22
SE.HIT
*/
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
public class ActivityDemoActivity extends Activity {
/** Called when the activity is first created. */
private static final String TAG = "demo";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Log.d("demo", "this is a test string ");
}
protected void onStart(){
super.onStart();
Log.i(TAG, "The activity state---->onStart");
}
protected void onRestart(){
super.onRestart();
Log.i(TAG, "The activity state---->onReatart");
}
protected void onResume(){
super.onResume();
Log.i(TAG, "The activity state---->onResume");
}
protected void onPause(){
super.onPause();
Log.i(TAG, "The activity state---->onPause");
}
protected void onStop(){
super.onStop();
Log.i(TAG, "The activity state---->onStop");
}
protected void onDestroy(){
super.onDestroy();
Log.i(TAG, "The activity state---->onDestroy");
}
}
这是演示的结果
利用LOG展示activity的生命周期
注释表示 中间执行的操作 为方便的观察数据,可以在LOGCAT窗口(没有的话可以在window菜单中的show view中调出)的右侧单击加号创建一个过滤器,我的例子中过滤的是demo
//开始运行demo 07-22 11:18:19.311: INFO/demo(281): The activity state---->onStart 07-22 11:18:19.311: INFO/demo(281): The activity state---->onResume //按下了back键 返回 activity从stack中弹出 07-22 11:18:34.821: INFO/demo(281): The activity state---->onPause 07-22 11:18:35.090: INFO/demo(281): The activity state---->onStop 07-22 11:18:35.090: INFO/demo(281): The activity state---->onDestroy //再次启动demo 07-22 11:18:45.550: INFO/demo(281): The activity state---->onStart 07-22 11:18:45.550: INFO/demo(281): The activity state---->onResume //按下了HOME键 当前TASK 处于后台转态,系统保存状态 07-22 11:18:53.750: INFO/demo(281): The activity state---->onPause 07-22 11:18:54.820: INFO/demo(281): The activity state---->onStop //再次启动demo 回复原来的TASK activity在栈顶 07-22 11:19:03.550: INFO/demo(281): The activity state---->onReatart 07-22 11:19:03.550: INFO/demo(281): The activity state---->onStart 07-22 11:19:03.550: INFO/demo(281): The activity state---->onResume
另外过滤查看log的方法:
实例

五个圆圈分别可以过滤五种不同的log
注意右边的绿色加号,单击可以自定义自己的过滤器,名字随便起就好了

by Log Tag栏目中 选择你要创建的过滤规则,比如你要过滤出所遇TAG标记为“yourDemo”的log,就可以在里面输入yourDemo了
希望本文所述对大家Android程序设计有所帮助。