安卓开发_深入理解Activity和Fragment的关系

时间:2022-05-16
本文章向大家介绍安卓开发_深入理解Activity和Fragment的关系,主要内容包括其使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

Fragment(碎片)是必须嵌入在 Activity(活动) 中使用的。Fragment的生命周期随着Activity的生命周期的变化而变化

一、首先让我们看下Activity和Fragment的生命周期对比

二、通过代码来看一下

 1 package com.xqx_life;
 2 
 3 import android.os.Bundle;
 4 import android.app.Activity;
 5 import android.app.FragmentManager;
 6 import android.app.FragmentTransaction;
 7 import android.view.Menu;
 8 
 9 public class MainActivity extends Activity {
10 
11     
12     @Override
13     protected void onCreate(Bundle savedInstanceState) {
14         super.onCreate(savedInstanceState);
15         setContentView(R.layout.activity_main);
16         MyFragment fragment = new MyFragment();
17         FragmentManager manager = getFragmentManager();
18         FragmentTransaction action = manager.beginTransaction();
19         action.add(R.id.show_fragment,fragment );
20         action.commit();
21         
22         System.out.println("现在执行Activity的  onCreate()方法");
23     }
24 
25     @Override
26     protected void onStart() {
27         // TODO Auto-generated method stub
28         super.onStart();
29         System.out.println("现在执行Activity的  onStart()方法");
30     }
31     
32     @Override
33     protected void onResume() {
34         // TODO Auto-generated method stub
35         super.onResume();
36         System.out.println("现在执行Activity的  onResume()方法");
37     }
38     
39     @Override
40     protected void onRestart() {
41         // TODO Auto-generated method stub
42         super.onRestart();
43         System.out.println("现在执行Activity的  onRestart()方法");
44     }
45     
46     @Override
47     protected void onPause() {
48         // TODO Auto-generated method stub
49         super.onPause();
50         System.out.println("现在执行Activity的  onPause()方法");
51     }
52     
53     @Override
54     protected void onStop() {
55         // TODO Auto-generated method stub
56         super.onStop();
57         System.out.println("现在执行Activity的  onStop()方法");
58     }
59     
60     @Override
61     protected void onDestroy() {
62         // TODO Auto-generated method stub
63         super.onDestroy();
64         System.out.println("现在执行Activity的  onDestroy()方法");
65     }
66     
67     
68 
69 }
 1 package com.xqx_life;
 2 
 3 import android.app.Activity;
 4 import android.app.Fragment;
 5 import android.os.Bundle;
 6 import android.view.LayoutInflater;
 7 import android.view.View;
 8 import android.view.ViewGroup;
 9 
10 public class MyFragment extends Fragment{
11     @Override
12     public View onCreateView(LayoutInflater inflater, ViewGroup container,
13             Bundle savedInstanceState) {
14         // TODO Auto-generated method stub
15         System.out.println("现在执行Fragment的  onCreateView()方法");
16         View view = inflater.inflate(R.layout.layout_fragment, container, false);
17         return view;
18     }
19     
20     @Override
21     public void onAttach(Activity activity) {
22         // TODO Auto-generated method stub
23         System.out.println("现在执行Fragment的  onAttach()方法");
24         super.onAttach(activity);
25     }
26     
27     @Override
28     public void onCreate(Bundle savedInstanceState) {
29         // TODO Auto-generated method stub
30         System.out.println("现在执行Fragment的  onCreate()方法");
31         super.onCreate(savedInstanceState);
32     }
33     
34     @Override
35     public void onActivityCreated(Bundle savedInstanceState) {
36         // TODO Auto-generated method stub
37         System.out.println("现在执行Fragment的  onActivityCreated()方法");
38         super.onActivityCreated(savedInstanceState);
39     }
40     
41     @Override
42     public void onStart() {
43         // TODO Auto-generated method stub
44         System.out.println("现在执行Fragment的  onStart()方法");
45         super.onStart();
46     }
47     
48     @Override
49     public void onResume() {
50         // TODO Auto-generated method stub
51         System.out.println("现在执行Fragment的  onResume()方法");
52         super.onResume();
53     }
54     
55     @Override
56     public void onPause() {
57         // TODO Auto-generated method stub
58         System.out.println("现在执行Fragment的  onPause()方法");
59         super.onPause();
60     }
61     
62     @Override
63     public void onStop() {
64         // TODO Auto-generated method stub
65         System.out.println("现在执行Fragment的  onStop()方法");
66         super.onStop();
67     }
68     
69     @Override
70     public void onDestroyView() {
71         // TODO Auto-generated method stub
72         System.out.println("现在执行Fragment的  onDestroyView()方法");
73         super.onDestroyView();
74     }
75     
76     @Override
77     public void onDestroy() {
78         // TODO Auto-generated method stub
79         System.out.println("现在执行Fragment的  onDestroy()方法");
80         super.onDestroy();
81         
82     }
83     
84     @Override
85     public void onDetach() {
86         // TODO Auto-generated method stub
87         System.out.println("现在执行Fragment的  onDetach()方法");
88         super.onDetach();
89     }
90     
91     
92 
93 }
1 <?xml version="1.0" encoding="utf-8"?>
2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3     android:layout_width="match_parent"
4     android:layout_height="match_parent"
5     android:orientation="vertical" >
6     
7 
8 </LinearLayout>

注意清单文件最低SDK版本要设置为11

1 <uses-sdk
2         android:minSdkVersion="11"
3         android:targetSdkVersion="21" />

看一下效果:

启动activity之后的生命

关闭activity 结束之前的生命