Fragment + viewpager Optimization

Fragment + viewpager Optimization

 

 

The last time I wrote a Q & A project, I used the fragment + viewpager architecture. Later I found that after a few strokes, I would drag them back and reload the layout and obtain data again, in this way, the entire program and card occupy too much network resources.

At that time, the solution was to rewrite the view and use the basic Basepageradapder to solve the problem elegantly.

At that time, I knew it was the reason for calling the onCreateView method again, but there was no good solution. Now I know it. here we will record it.

 

I tested viewpager to load four fragment:

The first entry:

 

03-01 13:50:16.151  22667-22667/com.graypn.modelproject I/onCreate1﹕ onCreate03-01 13:50:16.151  22667-22667/com.graypn.modelproject I/onCreateView1﹕ onCreateView03-01 13:50:16.161  22667-22667/com.graypn.modelproject I/onActivityCreated1﹕ onActivityCreated03-01 13:50:16.161  22667-22667/com.graypn.modelproject I/onCreate2﹕ onCreate03-01 13:50:16.161  22667-22667/com.graypn.modelproject I/onCreateView2﹕ onCreateView03-01 13:50:16.161  22667-22667/com.graypn.modelproject I/onActivityCreated2﹕ onActivityCreated

Slide right to the second interface:

 

 

03-01 13:51:22.391  22667-22667/com.graypn.modelproject I/onCreate3﹕ onCreate03-01 13:51:22.391  22667-22667/com.graypn.modelproject I/onCreateView3﹕ onCreateView03-01 13:51:22.401  22667-22667/com.graypn.modelproject I/onActivityCreated3﹕ onActivityCreated

Slide right to the third interface:

03-01 13:55:24.351  24165-24165/com.graypn.modelproject I/onDestroyView1﹕ onDestroyView03-01 13:55:24.351  24165-24165/com.graypn.modelproject I/onCreate4﹕ onCreate03-01 13:55:24.351  24165-24165/com.graypn.modelproject I/onCreateView4﹕ onCreateView03-01 13:55:24.361  24165-24165/com.graypn.modelproject I/onActivityCreated4﹕ onActivityCreated

Slide right to the fourth page:

03-01 13:56:22.021  24165-24165/com.graypn.modelproject I/onDestroyView2﹕ onDestroyView

Draw the third interface to the left:

03-01 13:58:09.541  24165-24165/com.graypn.modelproject I/onCreateView2﹕ onCreateView03-01 13:58:09.541  24165-24165/com.graypn.modelproject I/onActivityCreated2﹕ onActivityCreated

 

Conclusion: viewpager loads two fragment links to the current page, destroys the view of the third adjacent page, and CALLS oncreateview and onactivityreate again.

We need to optimize our fragment, as shown below:

 

/*** Provides the encapsulated post-base class of fragment, and provides the context to the sub-class using ** @ author Graypn */public abstract class basefrfragment extends Fragment {// Root view private View rootView; protected Context context; private Boolean hasInitData = false; @ Override public void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); context = getActivity () ;}@ Override public View onCreateView (LayoutInflater inflater, ViewGrou P container, Bundle savedInstanceState) {if (rootView = null) {rootView = initView (inflater);} return rootView;} @ Override public void onActivityCreated (Bundle savedInstanceState) {super. onActivityCreated (savedInstanceState); if (! HasInitData) {initData (); hasInitData = true ;}}@ Override public void onDestroyView () {super. onDestroyView (); (ViewGroup) rootView. getParent ()). removeView (rootView);}/*** sub-class implements initialization View operation */protected abstract View initView (LayoutInflater inflater);/*** sub-class implements initialization data operation (called by the sub-class itself) */public abstract void initData ();/*** encapsulate download data from the Network */protected void loadData (HttpRequest. httpMethod method, String url, RequestParams params, RequestCallBack
 
  
Callback) {if (0 = NetUtils. isNetworkAvailable (getActivity () {new CustomToast (getActivity (), no network, check the network connection !, 0). show () ;}else {NetUtils. loadData (method, url, params, callback );}}}
 

Add rootView to cache the loaded view. If yes, data is not reloaded.

 

Add a variable to identify whether the data has been loaded. If the data has been loaded, the data will not be reloaded.

It is an elegant solution to the optimization problem, hoping to help students with the same problem.