ViewStub ne se gonfle pas et la mise en page reste vide - Android

Question

Je travaille sur l'exemple de code généré lorsque vous démarrez un Navigation Drawer Activity dans Android Studio. Ce que j'essaye de faire est de changer une vue incluse par programme et ma recherche a montré que ViewStub est la meilleure manière de faire ceci. Cependant, je ne peux pas le faire fonctionner. Pour la mise en page principale en question, il y a 3 fichiers impliqués:

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?> 
<android.support.v4.widget.DrawerLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:id="@+id/drawer_layout" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:fitsSystemWindows="true" 
    tools:openDrawer="start"> 

    <include 
     layout="@layout/app_bar_main" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" /> 

    <android.support.design.widget.NavigationView 
     android:id="@+id/nav_view" 
     android:layout_width="wrap_content" 
     android:layout_height="match_parent" 
     android:layout_gravity="start" 
     android:fitsSystemWindows="true" 
     app:headerLayout="@layout/nav_header_main" 
     app:menu="@menu/activity_main_drawer" /> 

</android.support.v4.widget.DrawerLayout> 

app_bar_main.xml:

<?xml version="1.0" encoding="utf-8"?> 
<android.support.design.widget.CoordinatorLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:fitsSystemWindows="true" 
    tools:context="com.MY_APP.android.MainActivity"> 

    <android.support.design.widget.AppBarLayout 
     android:layout_height="wrap_content" 
     android:layout_width="match_parent" 
     android:theme="@style/AppTheme.AppBarOverlay"> 

     <android.support.v7.widget.Toolbar 
      android:id="@+id/toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="?attr/actionBarSize" 
      android:background="?attr/colorPrimary" 
      app:popupTheme="@style/AppTheme.PopupOverlay" /> 

    </android.support.design.widget.AppBarLayout> 

    <ViewStub 
     android:id="@+id/main_content" 
     android:inflatedId="@id/main_content" 
     android:layout="@layout/content_main" 
     android:layout_height="match_parent" 
     android:layout_width="match_parent"/> 

    <android.support.design.widget.FloatingActionButton 
     android:id="@+id/fab" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_gravity="bottom|end" 
     android:layout_margin="@dimen/fab_margin" 
     android:src="@android:drawable/ic_dialog_email" /> 

</android.support.design.widget.CoordinatorLayout> 

content_main.xml:

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    app:layout_behavior="@string/appbar_scrolling_view_behavior" 
    tools:showIn="@layout/app_bar_main" 
    tools:context="com.MY_APP.android.MainActivity"> 

    <TextView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:id="@+id/content_textview" 
     android:text="//TODO Main Feed"/> 
</RelativeLayout> 

Voici mon MainActivity.java. Rien ne semble se passer et content_main ne semble jamais apparaître. Serait-ce un problème de visibilité?

package com.myapp.android; 


import android.app.Dialog; 
import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.support.design.widget.NavigationView; 
import android.support.v4.view.GravityCompat; 
import android.support.v4.widget.DrawerLayout; 
import android.support.v7.app.ActionBarDrawerToggle; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.Toolbar; 
import android.view.MenuItem; 
import android.view.ViewStub; 
import android.widget.Toast; 

import com.facebook.FacebookSdk; 
import com.facebook.login.LoginManager; 
import com.google.android.gms.common.ConnectionResult; 
import com.google.android.gms.common.GooglePlayServicesUtil; 

import org.json.JSONException; 
import org.json.JSONObject; 

import java.util.ArrayList; 

public class MainActivity 
     extends AppCompatActivity 
     implements NavigationView.OnNavigationItemSelectedListener { 


    NetworkHelpers NetworkHelper = new NetworkHelpers(); 
    SharedPreferences sharedpreferences; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 

     //Check if user is connected 
     if(!NetworkHelper.checkConnectivity(this)){ 
      NetworkHelper.showNotConnectedAlert(this); 
     } 

     //Check for Google Play Services 
     checkGooglePlayServicesAvailable(); 

     //Get User Info From Database 
     sharedpreferences = getSharedPreferences("com.myapp.android.prefs", Context.MODE_PRIVATE); 
     String login_token = sharedpreferences.getString("login_token", ""); 
     String first_name = sharedpreferences.getString("first_name", ""); 
     String last_name = sharedpreferences.getString("last_name", ""); 
     String email = sharedpreferences.getString("email", ""); 


     if (login_token.isEmpty()){ 
      //Start LoginActivity 
      Intent intent = new Intent(this, LoginActivity.class); 
      intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION); 
      finish(); 
      startActivity(intent); 
     }else{ 
      //Update user info 
      ArrayList<String> params = new ArrayList<String>(); 
      params.add(login_token); 
      new getUserInfo().execute(params); 
     } 

     //Create View 
     super.onCreate(savedInstanceState); 
     setContentView(com.myapp.android.R.layout.activity_main); 

     //Set Toolbar and Navigation Drawer 
     Toolbar toolbar = (Toolbar) findViewById(com.myapp.android.R.id.toolbar); 
     setSupportActionBar(toolbar); 
     DrawerLayout drawer = (DrawerLayout) findViewById(com.myapp.android.R.id.drawer_layout); 
     ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
      this, drawer, toolbar, com.myapp.android.R.string.navigation_drawer_open, com.myapp.android.R.string.navigation_drawer_close); 
     drawer.setDrawerListener(toggle); 
     toggle.syncState(); 
     NavigationView navigationView = (NavigationView) findViewById(com.myapp.android.R.id.nav_view); 
     navigationView.setNavigationItemSelectedListener(this); 

     ViewStub stub = (ViewStub) findViewById(R.id.main_content); 
     stub.setLayoutResource(R.layout.content_main); 
     stub.inflate(); 

    } 

    @Override 
    public void onBackPressed() { 
     DrawerLayout drawer = (DrawerLayout) findViewById(com.myapp.android.R.id.drawer_layout); 
     if (drawer.isDrawerOpen(GravityCompat.START)) { 
      drawer.closeDrawer(GravityCompat.START); 
     } else { 
      super.onBackPressed(); 
     } 
    } 

    @SuppressWarnings("StatementWithEmptyBody") 
    @Override 
    public boolean onNavigationItemSelected(MenuItem item) { 
     int id = item.getItemId(); 

     if (id == R.id.nav_home) { 
      // Start Home Screen 
     } else if (id == R.id.nav_videos) { 
      // Start Videos Screen 
     } else if (id == R.id.nav_photos) { 
      // Start Photos Screen 
     } else if (id == R.id.nav_galleries) { 
      // Start Galleries Screen 
     } else if (id == R.id.nav_map) { 
      // Start Map Screen 
     } else if (id == com.myapp.android.R.id.nav_share) { 
      //Open share app dialog 
      Intent intent = new Intent(Intent.ACTION_SEND); 
      intent.setType("text/plain"); 
      intent.putExtra(Intent.EXTRA_SUBJECT, "My App"); 
      intent.putExtra(Intent.EXTRA_TEXT, "Check out My App: http://myapp.com/app"); 
      Intent chooser = Intent.createChooser(intent, "Tell a friend about My App"); 
      startActivity(chooser); 
     } else if (id == com.myapp.android.R.id.nav_logout){ 
      logout(); 
     } 

     DrawerLayout drawer = (DrawerLayout) findViewById(com.myapp.android.R.id.drawer_layout); 
     drawer.closeDrawer(GravityCompat.START); 
     return true; 
    } 

    //AsyncTask to get user info from api 
    class getUserInfo extends AsyncTask<ArrayList<String>, Void, String> { 
     @Override 
     protected String doInBackground(ArrayList<String>... params) { 
      String token = params[0].get(0); 
      String response = HttpRequest.post("http://api.myapp.com/users/get-info/").send("api_key=API_KEY&token="+token).body(); 
      return response; 
     } 

     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 
     } 

     @Override 
     protected void onPostExecute(String result) { 
      try { 
       // Do JSON Stuff 
       JSONObject jsonobject = new JSONObject(result); 
       String status = jsonobject.get("status").toString(); 
       String message = jsonobject.get("message").toString(); 
       JSONObject userinfo = jsonobject.getJSONObject("user_info"); 

       //Set up user variables 
       String first_name = userinfo.get("first_name").toString(); 
       String last_name = userinfo.get("last_name").toString(); 
       String email = userinfo.get("email").toString(); 
       String display_name = userinfo.get("display_name").toString(); 
       String about = userinfo.get("about").toString(); 
       String newsletter = userinfo.get("newsletter").toString(); 


       if (status.equals("success")){ 
        updateSharedPreferences(first_name, last_name, email, display_name, about, newsletter); 
       }else if (status.equals("error")){ 
        logout(); 
       } else{ 
        logout(); 
       } 

      } catch (JSONException e) { 
       Toast.makeText(getApplicationContext(),"An unknown error occurred.", Toast.LENGTH_SHORT).show(); 
       logout(); 
      } 
     } 
    } 

    private boolean checkGooglePlayServicesAvailable() { 
     final int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getApplicationContext()); 
     if (status == ConnectionResult.SUCCESS) { 
      return true; 
     } 

     if (GooglePlayServicesUtil.isUserRecoverableError(status)) { 
      final Dialog errorDialog = GooglePlayServicesUtil.getErrorDialog(status, this, 1); 
      if (errorDialog != null) 
      { 
       errorDialog.show(); 
      } 
     } 
     return false; 
    } 

    private void updateSharedPreferences(String first_name, String last_name, String email, String display_name, String about, String newsletter){ 
     //Put user info into sharedpreferences 
     SharedPreferences sharedpreferences = getSharedPreferences("com.myapp.android.prefs", Context.MODE_PRIVATE); 
     SharedPreferences.Editor editor = sharedpreferences.edit(); 
     editor.putString("first_name", first_name); 
     editor.putString("last_name", last_name); 
     editor.putString("email", email); 
     editor.putString("display_name", display_name); 
     editor.putString("about", about); 
     editor.putString("newsletter", newsletter); 
     editor.commit(); 
    } 

    private void logout(){ 
     //Logout of Facebook 
     FacebookSdk.sdkInitialize(this); 
     LoginManager.getInstance().logOut(); 

     //Unset shared preferences login token 
     SharedPreferences sharedpreferences = getSharedPreferences("com.myapp.android.prefs", Context.MODE_PRIVATE); 
     SharedPreferences.Editor editor = sharedpreferences.edit(); 
     editor.putString("login_token", ""); 
     editor.putString("facebook_token", ""); 
     editor.putString("google_token", ""); 
     editor.commit(); 

     //Open login screen 
     Intent intent = new Intent(getApplicationContext(), LoginActivity.class); 
     finish(); 
     startActivity(intent); 
    } 
} 

Answer 1

J'ai rencontré le même problème. Il semble que lorsque vous gonflez dynamiquement le StubView, le comportement est différent que lorsque vous utilisez simplement la balise <include> pour inclure une autre mise en page XML. Dans ce cas, après avoir été gonflé le contenu qui remplace le StubView n'est pas placé en dessous de la disposition AppBar, mais est positionné exactement derrière lui. Une façon de résoudre ce problème consiste à déplacer le RelativeLayout afin qu'il enveloppe le StubView. Ainsi, les changements ci-dessous sont nécessaires:

app_bar_main.xml:

<?xml version="1.0" encoding="utf-8"?> 
<android.support.design.widget.CoordinatorLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:fitsSystemWindows="true" 
    tools:context="com.MY_APP.android.MainActivity"> 

    <android.support.design.widget.AppBarLayout 
     android:layout_height="wrap_content" 
     android:layout_width="match_parent" 
     android:theme="@style/AppTheme.AppBarOverlay"> 

     <android.support.v7.widget.Toolbar 
      android:id="@+id/toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="?attr/actionBarSize" 
      android:background="?attr/colorPrimary" 
      app:popupTheme="@style/AppTheme.PopupOverlay" /> 

    </android.support.design.widget.AppBarLayout> 

    <!-- Changed Content --> 

    <RelativeLayout 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:paddingLeft="@dimen/activity_horizontal_margin" 
     android:paddingRight="@dimen/activity_horizontal_margin" 
     android:paddingTop="@dimen/activity_vertical_margin" 
     android:paddingBottom="@dimen/activity_vertical_margin" 
     app:layout_behavior="@string/appbar_scrolling_view_behavior" 
     tools:showIn="@layout/app_bar_main" 
     tools:context="com.MY_APP.android.MainActivity"> 

     <ViewStub 
      android:id="@+id/main_content" 
      android:inflatedId="@id/main_content" 
      android:layout="@layout/content_main" 
      android:layout_height="match_parent" 
      android:layout_width="match_parent"/> 

    </RelativeLayout> 

    <!-- Changed Content --> 

    <android.support.design.widget.FloatingActionButton 
     android:id="@+id/fab" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_gravity="bottom|end" 
     android:layout_margin="@dimen/fab_margin" 
     android:src="@android:drawable/ic_dialog_email" /> 

</android.support.design.widget.CoordinatorLayout> 

content_main.xml:

<?xml version="1.0" encoding="utf-8"?> 
<TextView 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:id="@+id/content_textview" 
    android:text="//TODO Main Feed"/>