L'application développée avec le menu de navigation, il montre "malheureusement le nom de l'application a arrêté" même avant l'ouverture de l'application

Question

J'ai développé l'application avec menu de navigation coulissant. il ne contient aucune erreur dans le projet. J'ai réussi à construire apk signé, mais après l'avoir installé sur le téléphone, il montre "malheureusement Appname s'est arrêté" avant même l'ouverture de l'application.

Manifest:

<?xml version="1.1" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.wAashiqeRasool.HamareNabi" > 

<uses-permission android:name="android.permission.INTERNET" /> 
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
<uses-permission android:name="android.permission.GET_ACCOUNTS" /> 
<uses-permission android:name="android.permission.READ_PROFILE" /> 
<uses-permission android:name="android.permission.READ_CONTACTS" /> 
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> 
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/> 
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/> 
android:hardwareAccelerated="true" 

<application 
    android:allowBackup="true" 
    android:icon="@mipmap/ic_launcher" 
    android:label="@string/app_name" 
    android:supportsRtl="true" 
    android:theme="@style/AppTheme" > 
    <activity 
     android:name="com.wAashiqeRasool.HamareNabi.MainActivity" 
     android:label="@string/app_name" 
     android:theme="@style/AppTheme.NoActionBar" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
    </application> 

</manifest> 

MainActivity:

package com.wAashiqeRasool.HamareNabi; 

import android.app.ProgressDialog; 
import android.content.Intent; 
import android.graphics.Bitmap; 
import android.net.Uri; 
import android.os.Bundle; 
import android.support.design.widget.FloatingActionButton; 
import android.support.design.widget.Snackbar; 
import android.view.KeyEvent; 
import android.view.View; 
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.Menu; 
import android.view.MenuItem; 
import android.webkit.WebSettings; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 

public class MainActivity extends AppCompatActivity 
    implements NavigationView.OnNavigationItemSelectedListener { 

//initializing WebView 
private WebView mwebView; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 

    FloatingActionButton fab = (FloatingActionButton) 
    findViewById(R.id.fab); 
    fab.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Snackbar.make(view, "Replace with your own action", 
Snackbar.LENGTH_LONG) 
        .setAction("Action", null).show(); 
     } 
    }); 

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
      this, drawer, toolbar, R.string.navigation_drawer_open, 
R.string.navigation_drawer_close); 
    drawer.setDrawerListener(toggle); 
    toggle.syncState(); 

    NavigationView navigationView = (NavigationView) 
findViewById(R.id.nav_view); 
    navigationView.setNavigationItemSelectedListener(this); 

    //WebView 
    mwebView = (WebView) findViewById(R.id.myWebView); 
    WebSettings webSettings = mwebView.getSettings(); 
    webSettings.setJavaScriptEnabled(true); 
    //improve webView performance 

mwebView.getSettings().setRenderPriority(WebSettings.RenderPriority.HIGH); 

mwebView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK); 
    mwebView.getSettings().setAppCacheEnabled(true); 
    mwebView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY); 
    webSettings.setDomStorageEnabled(true); 

webSettings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NARROW_COLUMNS); 
    webSettings.setUseWideViewPort(true); 
    webSettings.setSavePassword(true); 
    webSettings.setSaveFormData(true); 
    webSettings.setEnableSmoothTransition(true); 


    mwebView.loadUrl("www.hamarenabi.in?m=1"); 
    //force links open in webview only 
    mwebView.setWebViewClient(new MyWebviewClient()); 

} 

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

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 

    //noinspection SimplifiableIfStatement 
    if (id == R.id.action_settings) { 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 
} 

@SuppressWarnings("StatementWithEmptyBody") 
@Override 
public boolean onNavigationItemSelected(MenuItem item) { 
    // Handle navigation view item clicks here. 
    int id = item.getItemId(); 

    if (id == R.id.nav_us) { 
     // Handle the camera action 
     mwebView.loadUrl("http://www.hamarenabi.in/search/label/Asma-E- 
Husna?m=1"); 
    } else if (id == R.id.nav_world) { 
     mwebView.loadUrl("http://www.hamarenabi.in/p/nikah-in-islam- 
assalamu-alaikum-wa.html?m=1"); 
    } else if (id == R.id.nav_tech) { 
     mwebView.loadUrl("http://www.hamarenabi.in/search/label/aqaid-e- 
ahle%20sunnat?m=1"); 
    } else if (id == R.id.nav_sports) { 
     mwebView.loadUrl("http://www.hamarenabi.in/p/ramzan.html?m=1"); 
    } else if (id == R.id.nav_share) { 
     mwebView.loadUrl("http://www.hamarenabi.in/p/contact.html?m=1"); 
    } else if (id == R.id.nav_send) { 
     mwebView.loadUrl("http://www.hamarenabi.in/p/contact-us.html?m=1"); 
    } 

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

private class MyWebviewClient extends WebViewClient { 
    @Override 
    public boolean shouldOverrideUrlLoading(WebView view, String url) { 
     if (Uri.parse(url).getHost().equals("www.hamarenabi.in?m=1")) { 
      //open url contents in webview 
      return false; 
     } else { 
      //here open external links in external browser or app 
      Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url)); 
      startActivity(intent); 
      return true; 
     } 

    } 
    //ProgressDialogue 
    ProgressDialog pd = null; 

    @Override 
    public void onPageStarted(WebView view, String url, Bitmap favicon) { 
     pd=new ProgressDialog(MainActivity.this); 
     pd.setTitle("Please Wait.."); 
     pd.setMessage("Website is Loading.."); 
     pd.show(); 
     super.onPageStarted(view, url, favicon); 
    } 

    @Override 
    public void onPageFinished(WebView view, String url) { 
     pd.dismiss(); 
     super.onPageFinished(view, url); 
    } 
} 
//goto previous page when pressing back button 

@Override 
public boolean onKeyDown(int keyCode, KeyEvent event) { 
    if (event.getAction() == KeyEvent.ACTION_DOWN) { 
     switch (keyCode) { 
      case KeyEvent.KEYCODE_BACK: 
       if (mwebView.canGoBack()) { 
        mwebView.goBack(); 
       } else { 
        finish(); 
       } 
       return true; 
     } 
    } 
    return super.onKeyDown(keyCode, event); 
} 
} 

build.gradle (App modulaire):

apply plugin: 'com.android.application' 

android { 
compileSdkVersion 23 
buildToolsVersion '25.0.0' 

defaultConfig { 
    applicationId "com.wAashiqeRasool.HamareNabi" 
    minSdkVersion 21 
    targetSdkVersion 23 
    versionCode 1 
    versionName "1.1" 
} 
buildTypes { 
    release { 
     minifyEnabled false 
     proguardFiles getDefaultProguardFile('proguard-android.txt'), 
'proguard-rules.pro' 
    } 
} 
} 

dependencies { 
compile fileTree(dir: 'libs', include: ['*.jar']) 
testCompile 'junit:junit:4.12' 
compile 'com.android.support:appcompat-v7:23.0.0' 
compile 'com.android.support:design:23.0.0' 
} 

Answer 1

Le crash est parce que la variable 'pd' est nul dans votre OnPageFinished() appel. Ajoutez une vérification null comme indiqué ci-dessous et vous ne verrez aucun crash dans onPageFinished().

@Override 
    public void onPageFinished(WebView view, String url) { 
     if(pd != null) 
      pd.dismiss(); 
     super.onPageFinished(view, url); 
    }