异常 android.support.multidex.MultiDexApplication 不能强制转换类

Question

我有一个问题，我的应用程序生成了这个异常，我不明白。 我在 build.gradle 中实现了 multiDexEnabled

  Caused by: java.lang.ClassCastException: android.support.multidex.MultiDexApplication cannot be cast to com.example.AnalyticsApplication

我的 Java 课堂

public class Splash extends Activity {

 private Tracker mTracker;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
  requestWindowFeature(Window.FEATURE_NO_TITLE);
  setContentView(R.layout.activity_splash);

  //Analitycs
  AnalyticsApplication application = (AnalyticsApplication) getApplication();
  mTracker = application.getDefaultTracker();
  mTracker.setScreenName("Splash");
  mTracker.send(new HitBuilders.ScreenViewBuilder().build());

}

文件 Gradle

 defaultConfig {
    multiDexEnabled true
}

Manifest.xml

<uses-permissionandroid:name="android.permission.INTERNET"/>
<uses-permissionandroid:name="android.permission.ACCESS_NETWORK_STATE"/>

<application
android:name="android.support.multidex.MultiDexApplication"
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activityandroid:name=".Splash">
<intent-filter>
<actionandroid:name="android.intent.action.MAIN"/>
<categoryandroid:name="android.intent.category.LAUNCHER"/>
</intent-filter></activity>
</application>

Answer 1

我认为您应该将AnalyticsApplication 类扩展为您自己的类，如下所示：

public class YourApplicationName extends AnalyticsApplication {

     @Override
     protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);

          setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
          requestWindowFeature(Window.FEATURE_NO_TITLE);
          setContentView(R.layout.activity_splash);

          //Analitycs
          AnalyticsApplication application = (AnalyticsApplication) getApplication();
          mTracker = application.getDefaultTracker();
          mTracker.setScreenName("Splash");
          mTracker.send(new HitBuilders.ScreenViewBuilder().build());
     }

     // Here you will enable Multidex
     @Override
     protected void attachBaseContext(Context base) {
          super.attachBaseContext(base);
          MultiDex.install(getBaseContext());
     }

}

在此之后，您必须将您的 AndroidManifest.xml 文件更改为：

<application
     android:name="path.to.YourApplicationName"
     ...

请查看此链接以获取更多信息：http://developer.android.com/reference/android/support/multidex/MultiDex.html

Answer 2

我有同样的问题，因为你在清单中设置了android:name="android.support.multidex.MultiDexApplication"，所以你的应用程序调用类型为MultiDexApplication

<application
android:name="android.support.multidex.MultiDexApplication"
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activityandroid:name=".Splash">
<intent-filter>
<actionandroid:name="android.intent.action.MAIN"/>
<categoryandroid:name="android.intent.category.LAUNCHER"/>
</intent-filter></activity>
</application>

我的应用类

public class MyApplication extends Application {


    public enum TrackerName {
        APP_TRACKER, // tracker used only in this app
        GLOBAL_TRACKER, // tracker used by all the apps from a company . eg: roll-up tracking.
        ECOMMERCE_TRACKER, // tracker used by all ecommerce transactions from a company .
    }

    public HashMap<TrackerName, Tracker> mTrackers = new HashMap<>();

    public synchronized Tracker getTracker(TrackerName trackerId) {
        if (!mTrackers.containsKey(trackerId)) {
            GoogleAnalytics analytics = GoogleAnalytics.getInstance(this);
            Tracker tracker = (trackerId == TrackerName.APP_TRACKER)?analytics.newTracker(Property_ID)
                    : (trackerId == TrackerName.GLOBAL_TRACKER) ? analytics.newTracker(R.xml.global_tracker)
                    : analytics.newTracker(R.xml.ecommerce_tracker);
            mTrackers.put(trackerId , tracker);
        }
        return  mTrackers.get(trackerId);
    }


    private Activity mCurrentActivity = null;

    public void setCurrentActivity(Activity mCurrectActivity) {
        this.mCurrentActivity = mCurrectActivity;
    }

    public Activity getCurrentActivity() {
        return mCurrentActivity;
    }

    private static Context mAppContext;

    private static MyApplication mInstance;

    @Override
    public void onCreate() {
        super.onCreate();
        MultiDex.install(this);
        mInstance = this;
        this.setAppContext(getApplicationContext());
    }

    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
        MultiDex.install(this);
    }

    public static MyApplication getInstance() {
        return mInstance;
    }

    public static Context getAppContext() {
        return mAppContext;
    }

    public void setAppContext(Context mAppContext) {
        this.mAppContext = mAppContext;
    }

}

这就是为什么当我调用这个方法（初始化应用程序实例）它崩溃时，它尝试将MultiDexApplication 转换为MyApplication

MyApplication application = (MyApplication)getApplication();

所以要解决这个问题，只需将清单属性名称更改为 MyApplication

<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        android:name=".MyApplication"> // add path to your application class here 

Answer 3

您应该从MultidexApplication 扩展您的Application 类并在清单中使用它，而不是直接使用android.support.multidex.MultiDexApplication。

Answer 4

这里有几个正确的解决方案。但是，如果您使用的是 react-native >= 0.60 或者您使用的是 androidx，那么这就是解决方案：

// MainApplication

...
import androidx.multidex.MultiDexApplication;

...    

public class MainApplication extends MultiDexApplication implements ReactApplication {

    ...
}

Answer 5

删除那一行

 android:name="android.support.multidex.MultiDexApplication"  

从清单文件中输入您的应用程序名称。即

 android:name="com.yourAppNamae.activity.YourApplicationName"

这对我有用

Answer 6

React Native：

// MainApplication

...

import android.content.Context;
import android.support.multidex.MultiDex;

...    

public class MainApplication extends Application implements ReactApplication {

    ...

    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
        MultiDex.install(getBaseContext());
    }
}

Answer 7

添加到@Chandan 的答案，真正保持您的原始应用程序 android:name 在 AndroidManifest.xml 使它工作（至少在我的情况下，RN > 0.60 并使用 Androidx）。