//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");
  }
}

//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