I just experienced an awkward bug in my App.
On my Nexus 5/7, running android 5.0.1/5.0.2, everything works just fine. However if i try running the exact same code on a device with an earlier version (tested 4.4.4 and 4.3) I get the following error:
03-13 13:49:41.140 21714-21714/? E/dalvikvm﹕ Could not find class 'com.default.package.application.model.Appcomponent', referenced from method com.default.package.application.controller.DatabaseHandler.getScreenComponents
03-13 13:49:41.140 21714-21714/? E/dalvikvm﹕ Could not find class 'android.support.v7.app.ActionBarActivityDelegate$1', referenced from method android.support.v7.app.ActionBarActivityDelegate.<init>
03-13 13:49:41.140 21714-21714/? E/dalvikvm﹕ Could not find class 'android.support.v7.app.ActionBarActivityDelegateHC', referenced from method android.support.v7.app.ActionBarActivityDelegate.createDelegate
03-13 13:49:41.140 21714-21714/? E/dalvikvm﹕ Could not find class 'android.support.v7.app.ActionBarActivityDelegateBase', referenced from method android.support.v7.app.ActionBarActivityDelegate.createDelegate
03-13 13:49:41.150 21714-21714/? E/dalvikvm﹕ Could not find class 'android.support.v7.app.ActionBarActivityDelegate$ActionBarDrawableToggleImpl', referenced from method android.support.v7.app.ActionBarActivityDelegate.getDrawerToggleDelegate
03-13 13:49:41.150 21714-21714/? E/dalvikvm﹕ Could not find class 'android.support.v7.internal.view.SupportMenuInflater', referenced from method android.support.v7.app.ActionBarActivityDelegate.getMenuInflater
03-13 13:49:41.150 21714-21714/? E/dalvikvm﹕ Could not find class 'android.support.v7.app.ActionBarActivityDelegate$ActionBarDrawableToggleImpl', referenced from method android.support.v7.app.ActionBarActivityDelegate.getV7DrawerToggleDelegate
03-13 13:49:41.150 21714-21714/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.default.package, PID: 21714
java.lang.NoClassDefFoundError: android.support.v7.app.ActionBarActivityDelegateHC
I've already tried adding the support.v7 library as jar, but makes no difference. But since it works on Lollipop devices this wouldn't make sense anyway.
Could it be that there's some issue concerning the Dalvik/Art change? Or maybe the fact that I had to use com.android.support:multidex:1.0.0 since it's a rather large app.
Update: I tried removing some dependencies to get under the 65k method limit. After that the app ran on 4.4.4 and 4.3 devices. All I did for enabling multidex support was setting
multiDexEnabled true
in the defaultConfig section and adding
compile 'com.android.support:multidex:1.0.0'
below in the dependencies section of my build.gradle.
Any idea why this causes these issues on the older android versions?
I resolved the issue by adding this to my Application Class.
@Override
protected void attachBaseContext(Context base) {
super.attachBaseContext(base);
MultiDex.install(this);
}
Seems to be neccessary for android versions prior 5.
There are three ways how this is going to work.
- As @FireZenk noted you can declare this class as the application in your AndroidManifest.xml.
<application android:name="android.support.multidex.MultiDexApplication">
And actually with the android grade plugin version 0.14.0 and build tools version 21.1.0 when you specify the multiDexEnabled true in the defaultConfig, ProductFlavor, or BuildTypethen it automatically includes dependence to the com.android.support:multidex:1.0.0. You can check that with the androidDependencie task or you run ./gradlew -q android:dependencies command (android: is my android module). So there is no need to explicitly add the
compile 'com.android.support:multidex:1.0.0'
If you have extended Application class in your app:
- Define that your Application extends MultiDexApplication class, like:
public class MyApplication extends MultiDexApplication {
...
}
or like @user2700475 posted
- Have your Application override attachBaseContext:
public class MyApplication extends Application {
@Override
protected void attachBaseContext(Context base) {
super.attachBaseContext(base);
MultiDex.install(this);}
}
With the help of previous answers I manage to find the solution to this problem. I just want to put all this together.
If you don't have/use Application class, you can put this:
android:name="android.support.multidex.MultiDexApplication"
Into your tag on AndroidManifest.xml
If you already have implemented an Application class, @user2700475 + @sirvon responses are your best choice.
Also obviously, you need to add the Gradle dependency:
compile 'com.android.support:multidex:1.0.0'
More info about 65k methods problem: https://developer.android.com/tools/building/multidex.html
来源：https://stackoverflow.com/questions/29033800/noclassdeffounderror-below-sdk-21