安卓开发_深入理解Activity和Fragment的关系

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

package com.xqx_life;

import android.os.Bundle;
import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.view.Menu;

public class MainActivity extends Activity {

    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        MyFragment fragment = new MyFragment();
        FragmentManager manager = getFragmentManager();
        FragmentTransaction action = manager.beginTransaction();
        action.add(R.id.show_fragment,fragment );
        action.commit();
        
        System.out.println("现在执行Activity的  onCreate()方法");
    }

    @Override
    protected void onStart() {
        // TODO Auto-generated method stub
        super.onStart();
        System.out.println("现在执行Activity的  onStart()方法");
    }
    
    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        System.out.println("现在执行Activity的  onResume()方法");
    }
    
    @Override
    protected void onRestart() {
        // TODO Auto-generated method stub
        super.onRestart();
        System.out.println("现在执行Activity的  onRestart()方法");
    }
    
    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        System.out.println("现在执行Activity的  onPause()方法");
    }
    
    @Override
    protected void onStop() {
        // TODO Auto-generated method stub
        super.onStop();
        System.out.println("现在执行Activity的  onStop()方法");
    }
    
    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        System.out.println("现在执行Activity的  onDestroy()方法");
    }
    
    

}

package com.xqx_life;

import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MyFragment extends Fragment{
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onCreateView()方法");
        View view = inflater.inflate(R.layout.layout_fragment, container, false);
        return view;
    }
    
    @Override
    public void onAttach(Activity activity) {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onAttach()方法");
        super.onAttach(activity);
    }
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onCreate()方法");
        super.onCreate(savedInstanceState);
    }
    
    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onActivityCreated()方法");
        super.onActivityCreated(savedInstanceState);
    }
    
    @Override
    public void onStart() {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onStart()方法");
        super.onStart();
    }
    
    @Override
    public void onResume() {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onResume()方法");
        super.onResume();
    }
    
    @Override
    public void onPause() {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onPause()方法");
        super.onPause();
    }
    
    @Override
    public void onStop() {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onStop()方法");
        super.onStop();
    }
    
    @Override
    public void onDestroyView() {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onDestroyView()方法");
        super.onDestroyView();
    }
    
    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onDestroy()方法");
        super.onDestroy();
        
    }
    
    @Override
    public void onDetach() {
        // TODO Auto-generated method stub
        System.out.println("现在执行Fragment的  onDetach()方法");
        super.onDetach();
    }
    
    

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    

</LinearLayout>

注意清单文件最低SDK版本要设置为11

<uses-sdk
        android:minSdkVersion="11"
        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