014_01关于Activity的生命周期

 1 package com.example.day14_01activitylifecycle;
 2 
 3 import android.app.Activity;
 4 import android.content.Intent;
 5 import android.os.Bundle;
 6 import android.util.Log;
 7 import android.view.View;
 8 
 9 public class MainActivity extends Activity {
10     public static final  String TAG = "day14_01activitylifecycle";
11     public void click(View v){
12         Intent intent = new Intent();
13         intent.setClass(this, SecondActivity.class);
14         startActivity(intent);
15     }
16     @Override
17     protected void onCreate(Bundle savedInstanceState) {
18         super.onCreate(savedInstanceState);
19         setContentView(R.layout.activity_main);
20         Log.i(TAG, "onCreate()");
21     }
22     @Override
23     protected void onStart() {
24         // TODO Auto-generated method stub
25         super.onStart();
26         Log.i(TAG, "onStart()");
27     }
28     @Override
29     protected void onResume() {
30         // TODO Auto-generated method stub
31         super.onResume();
32         Log.i(TAG, "onResume()");
33 
34     }
35     @Override
36     protected void onRestart() {
37         // TODO Auto-generated method stub
38         super.onRestart();
39         Log.i(TAG, "onRestart()");
40 
41     }
42     @Override
43     protected void onPause() {
44         // TODO Auto-generated method stub
45         super.onPause();
46         Log.i(TAG, "onPause()");
47     }
48     @Override
49     protected void onStop() {
50         // TODO Auto-generated method stub
51         super.onStop();
52         Log.i(TAG, "onStop()");
53     }
54     @Override
55     protected void onDestroy() {
56         // TODO Auto-generated method stub
57         super.onDestroy();
58         Log.i(TAG, "onDestroy()");
59     }
60 }

 1 package com.example.day14_01activitylifecycle;
 2 
 3 import android.app.Activity;
 4 import android.os.Bundle;
 5 
 6 public class SecondActivity extends Activity {
 7 
 8     @Override
 9     protected void onCreate(Bundle savedInstanceState) {
10         // TODO Auto-generated method stub
11         super.onCreate(savedInstanceState);
12         setContentView(R.layout.activity_main);    
13     }
14 }

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:paddingBottom="@dimen/activity_vertical_margin"
 6     android:paddingLeft="@dimen/activity_horizontal_margin"
 7     android:paddingRight="@dimen/activity_horizontal_margin"
 8     android:paddingTop="@dimen/activity_vertical_margin"
 9     tools:context="com.example.day14_01activitylifecycle.MainActivity" >
10 
11     <TextView
12         android:layout_width="wrap_content"
13         android:layout_height="wrap_content"
14         android:text="@string/hello_world" />
15     
16     
17     <Button
18         android:id="@+id/bt"
19         android:onClick="click"
20         android:layout_width="wrap_content"
21         android:layout_height="wrap_content"
22         android:text="click me " 
23         android:layout_centerHorizontal="true"/>
24 
25       <EditText
26            android:id="@+id/et"
27         android:layout_width="fill_parent"
28         android:layout_height="wrap_content"
29         android:layout_centerHorizontal="true"
30         android:layout_below="@id/bt"/>
31 </RelativeLayout>