java.lang.ClassNotFoundException: android.graphics.drawable.RippleDrawable

Question:

In short my situation: I have a code that using the old Qt 5.3.2 was able to run into android. Same code, once moved to latest Qt 5.4 ( and latest version of Qt Creator too) doesn't work anymore. I tried all the possible combination but without success.
Before report the error please note I'm still using Ant for apk packaging since if I select Gradle the tool attept to download the gradle zip file but I'm through a proxy and the download fail.Currently the target of my app is android-15 but when I execute
the following error show up in the console:

@W/System.err( 1330): java.lang.ClassNotFoundException:
android.graphics.drawable.RippleDrawable

W/System.err( 1330): at java.lang.Class.classForName(Native Method)

W/System.err( 1330): at java.lang.Class.forName(Class.java:217)

W/System.err( 1330): at java.lang.Class.forName(Class.java:172)

W/System.err( 1330): at org.qtproject.qt5.android.ExtractStyle.getClass(ExtractStyle.java:396)

W/System.err( 1330): at org.qtproject.qt5.android.ExtractStyle.<init>(ExtractStyle.java:100)

W/System.err( 1330): at org.qtproject.qt5.android.QtActivityDelegate.loadApplication(QtActivityDelegate.java:438)

W/System.err( 1330): at java.lang.reflect.Method.invokeNative(Native Method)

W/System.err( 1330): at java.lang.reflect.Method.invoke(Method.java:511)

W/System.err( 1330): at org.qtproject.qt5.android.bindings.QtActivity.loadApplication(QtActivity.java:245)

W/System.err( 1330): at org.qtproject.qt5.android.bindings.QtActivity.startApp(QtActivity.java:655)

W/System.err( 1330): at org.qtproject.qt5.android.bindings.QtActivity.onCreate(QtActivity.java:895)

W/System.err( 1330): at android.app.Activity.performCreate(Activity.java:4465)

W/System.err( 1330): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)

W/System.err( 1330): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)

W/System.err( 1330): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)

W/System.err( 1330): at android.app.ActivityThread.access$600(ActivityThread.java:123)

W/System.err( 1330): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)

W/System.err( 1330): at android.os.Handler.dispatchMessage(Handler.java:99)

W/System.err( 1330): at android.os.Looper.loop(Looper.java:137)

W/System.err( 1330): at android.app.ActivityThread.main(ActivityThread.java:4424)

W/System.err( 1330): at java.lang.reflect.Method.invokeNative(Native Method)

W/System.err( 1330): at java.lang.reflect.Method.invoke(Method.java:511)

W/System.err( 1330): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)

W/System.err( 1330): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)

W/System.err( 1330): at dalvik.system.NativeStart.main(Native Method)

W/System.err( 1330): Caused by: java.lang.NoClassDefFoundError: android/graphics/drawable/RippleDrawable

W/System.err( 1330): ... 25 more

W/System.err( 1330): Caused by: java.lang.ClassNotFoundException: android.graphics.drawable.RippleDrawable

W/System.err( 1330): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)

W/System.err( 1330): at java.lang.ClassLoader.loadClass(ClassLoader.java:501)

W/System.err( 1330): at java.lang.ClassLoader.loadClass(ClassLoader.java:461)

W/System.err( 1330): ... 25 more

.......

the component "RippleDrawable" has been introduced into latest android-21 but is not my target.Someone can help?Thank you

Answer1:

Forget it, I just tested one of the examples provided witht the Qt package and this error was showed same mode but the app start. This mean there is something other making the app crash using version 5.4. Looking for the problem...

Answer2:

As you can read from my first posts here this error (java.lang.ClassNotFoundException: android.graphics.drawable.RippleDrawable) it isn't critical since it happen using standard Qt examples too. Basically RippleDrawableis a class introduced in android 5,
in all older version this error came up but the app start equally than is not the problem.

原文地址：https://forum.qt.io/topic/49282/solved-unable-to-run-on-android-using-qt-5-4