使用 Fragment&&Fragment的生命周期&&带侧边栏的 Activity&&Tabbed Activity

1、使用 Fragment

• fragment作为界面切换的代价比Activity小。切换很方便。是可以理解为一个Activity的模版。
• 跳转fragment：

  • public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            rootView.findViewById(R.id.ShowAnotherFragment).setOnClickListener(new View.OnClickListener() {    
                @Override
                public void onClick(View v) {
                    getFragmentManager().
                    beginTransaction().
                    addToBackStack(null).
                    replace(R.id.container, new anotherfragment()).
                    commit();
                }
            });
            return rootView;
        }

• • public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootview = inflater.inflate(R.layout.fragment_another, container,false);
            
            rootview.findViewById(R.id.Back).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    getFragmentManager().popBackStack();
                }
            });
            
            return rootview;
        }

2、Fragment的生命周期

• Fragment的生命周 

            

• 与Activity生命周期的对比

       

  场景演示 : 切换到该Fragment

  11-29 14:26:35.095: D/AppListFragment(7649): onAttach
  11-29 14:26:35.095: D/AppListFragment(7649): onCreate
  11-29 14:26:35.095: D/AppListFragment(7649): onCreateView
  11-29 14:26:35.100: D/AppListFragment(7649): onActivityCreated
  11-29 14:26:35.120: D/AppListFragment(7649): onStart
  11-29 14:26:35.120: D/AppListFragment(7649): onResume

  屏幕灭掉：

  11-29 14:27:35.185: D/AppListFragment(7649): onPause
  11-29 14:27:35.205: D/AppListFragment(7649): onSaveInstanceState
  11-29 14:27:35.205: D/AppListFragment(7649): onStop

  屏幕解锁

  11-29 14:33:13.240: D/AppListFragment(7649): onStart
  11-29 14:33:13.275: D/AppListFragment(7649): onResume

  切换到其他Fragment:
  11-29 14:33:33.655: D/AppListFragment(7649): onPause
  11-29 14:33:33.655: D/AppListFragment(7649): onStop
  11-29 14:33:33.660: D/AppListFragment(7649): onDestroyView

  切换回本身的Fragment:

  11-29 14:33:55.820: D/AppListFragment(7649): onCreateView
  11-29 14:33:55.825: D/AppListFragment(7649): onActivityCreated
  11-29 14:33:55.825: D/AppListFragment(7649): onStart
  11-29 14:33:55.825: D/AppListFragment(7649): onResume

  回到桌面

  11-29 14:34:26.590: D/AppListFragment(7649): onPause
  11-29 14:34:26.880: D/AppListFragment(7649): onSaveInstanceState
  11-29 14:34:26.880: D/AppListFragment(7649): onStop

  回到应用

  11-29 14:36:51.940: D/AppListFragment(7649): onStart
  11-29 14:36:51.940: D/AppListFragment(7649): onResume

  退出应用

  11-29 14:37:03.020: D/AppListFragment(7649): onPause
  11-29 14:37:03.155: D/AppListFragment(7649): onStop
  11-29 14:37:03.155: D/AppListFragment(7649): onDestroyView
  11-29 14:37:03.165: D/AppListFragment(7649): onDestroy
  11-29 14:37:03.165: D/AppListFragment(7649): onDetach

3、带侧边栏的Activity：

• 这个接口是Activity与侧边栏之间的关键：

• public static interface NavigationDrawerCallbacks {
          /**
           * Called when an item in the navigation drawer is selected.
           */
          void onNavigationDrawerItemSelected(int position);
          
          void onGoLiyang();
      }

• 侧边栏获得Activity：

  • @Override
        public void onAttach(Activity activity) {
            super.onAttach(activity);
            try {
                mCallbacks = (NavigationDrawerCallbacks) activity;
            } catch (ClassCastException e) {
                throw new ClassCastException(
                        "Activity must implement NavigationDrawerCallbacks.");
            }
        }

• 侧边栏调用接口函数达到切换fragment目的：

  • public class SliderActivity extends Activity implements
            NavigationDrawerFragment.NavigationDrawerCallbacks {
    
        。。。。
    
        @Override
        public void onGoLiyang() {
            getFragmentManager()
            .beginTransaction()
            .replace(R.id.container, new WebLiyang())
            .commit();
        }
            。。。。
    
    }

4、Tabbed Activity使用

• @Override
          public Fragment getItem(int position) {
              // getItem is called to instantiate the fragment for the given page.
              // Return a PlaceholderFragment (defined as a static inner class
              // below).
              //return PlaceholderFragment.newInstance(position + 1);
              switch (position) {
              case 0:
                  return new Image1Fm();
              case 1:
                  return new Image2Fm();
              case 2:
                  return new Image3Fm();
              }
              return null;
          }