学习fragment的生命周期

fragment作用：用于多屏显示，可以把activity里面的逻辑进行分离。3.0的时候就开始有的(平板)，4.0被加载到手机中。

fragment也可以看成一个view，依附于activity之上，fragment的生命周期可以说是由activity来控制的。

fragment上面必须有view才能被显示。

fragment：在布局中必须指定id和全类名 如下：

    <fragment
        android:id="@+id/fragment"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        class="com.android.hzy.fragment.MyFragment" />

 

具体代码

布局代码：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <fragment
        android:id="@+id/fragment"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        class="com.android.hzy.fragment.MyFragment" />

</LinearLayout>

fragment

package com.android.hzy.fragment;

import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MyFragment extends Fragment {

    @Override
    public void onAttach(Activity activity) {
        // TODO Auto-generated method stub
        super.onAttach(activity);
        
        Log.i("i", "  MyFragment onAttach() ");
    }
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        
        Log.i("i", "  MyFragment onCreate() ");
    }
    
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        Log.i("i", "  MyFragment onCreateView() ");
        
        TextView tv = new TextView(getActivity());
        tv.setText("我的fragment");
        
        return tv;
    }
    
    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onActivityCreated(savedInstanceState);
        Log.i("i", "  MyFragment onActivityCreated() ");
    }
    
    @Override
    public void onStart() {
        // TODO Auto-generated method stub
        super.onStart();
        Log.i("i", "  MyFragment onStart() ");
    }
    
    @Override
    public void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        Log.i("i", "  MyFragment onResume() ");
    }
    
    @Override
    public void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        Log.i("i", "  MyFragment onPause() ");
    }
    
    @Override
    public void onStop() {
        // TODO Auto-generated method stub
        super.onStop();
        Log.i("i", "  MyFragment onStop() ");
    }
    
    @Override
    public void onDestroyView() {
        // TODO Auto-generated method stub
        super.onDestroyView();
        Log.i("i", "  MyFragment onDestroyView() ");
    }
    
    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        Log.i("i", "  MyFragment onDestroy() ");
    }
    
    @Override
    public void onDetach() {
        // TODO Auto-generated method stub
        super.onDetach();
        Log.i("i", "  MyFragment onDetach() ");
    }
    
}

MainActivity

package com.android.hzy.fragment;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        Log.i("i", "                    MainActivity     onCreate()               ");
    }

    @Override
    protected void onStart() {
        // TODO Auto-generated method stub
        super.onStart();
        Log.i("i", "                    MainActivity     onStart()               ");
    }
    
    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        Log.i("i", "                    MainActivity     onResume()               ");
    }
    
    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        Log.i("i", "                    MainActivity     onPause()               ");
    }
    
    @Override
    protected void onStop() {
        // TODO Auto-generated method stub
        super.onStop();
        Log.i("i", "                    MainActivity     onStop()               ");
    }
    
    @Override
    protected void onRestart() {
        // TODO Auto-generated method stub
        super.onRestart();
        Log.i("i", "                    MainActivity     onRestart()               ");
        
    }
    
    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        Log.i("i", "                    MainActivity     onDestroy()               ");
    }
    
    
}

***********************************总结*******************************************　　　　　　　　　

*                                             显示到前台：
*                                            MyFragment onAttach() 粘贴到activity上
*                                            MyFragment onCreate() fragment创建
*                                            MyFragment onCreateView() fragment创建自己的视图

*                                            MainActivity onCreate()
*                                            MyFragment onActivityCreated() 可以处理fragment数据的初始化

*                                            MainActivity onStart()
*                                            MyFragment onStart()

*                                            MainActivity onResume()
*                                            MyFragment onResume()

*                                            按后退键
*                                            MyFragment onPause()
*                                            MainActivity onPause()

*                                            MyFragment onStop()
*                                            MainActivity onStop()

*                                            MyFragment onDestoryView() 销毁掉自己的视图
*                                            MyFragment onDestory()
*                                            MyFragment onDetach() 解除和activity的关系

*                                            MainActivity onDestory()