当我尝试在Android4.4.2上运行我的应用程序时，它会给我一个错误：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: my.package, PID: 24775
java.lang.NoClassDefFoundError: my/package/models/Transaction
at java.lang.Class.getDeclaredFields(Native Method)
at java.lang.Class.getDeclaredFields(Class.java:610)
at com.activeandroid.util.ReflectionUtils.getDeclaredColumnFields(ReflectionUtils.java:73)
at com.activeandroid.TableInfo.<init>(TableInfo.java:66)
at com.activeandroid.ModelInfo.loadModelFromMetaData(ModelInfo.java:101)
at com.activeandroid.ModelInfo.<init>(ModelInfo.java:61)
at com.activeandroid.Cache.initialize(Cache.java:66)
at com.activeandroid.ActiveAndroid.initialize(ActiveAndroid.java:44)
at com.activeandroid.ActiveAndroid.initialize(ActiveAndroid.java:34)
at com.activeandroid.content.ContentProvider.onCreate(ContentProvider.java:39)
at android.content.ContentProvider.attachInfo(ContentProvider.java:1591)
at android.content.ContentProvider.attachInfo(ContentProvider.java:1562)
at android.app.ActivityThread.installProvider(ActivityThread.java:5233)
at android.app.ActivityThread.installContentProviders(ActivityThread.java:4827)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4710)
at android.app.ActivityThread.access$1600(ActivityThread.java:174)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1367)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5593)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: Didn't find class "my.package.models.Transaction" on path: DexPathList[[zip file "/data/app/my.package-1.apk"],nativeLibraryDirectories=[/data/app-lib/my.package-1, /vendor/lib, /system/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:67)
at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
然而，对于android 5.0及更高版本来说，它工作正常，没有任何错误。
原因是什么？我该怎么解决？
注意：stackoverflow上有一个类似的问题，但没有任何答案。
最佳答案
你可以在这里找到这个问题的答案：
NoClassDefFoundError with Android Studio on Android 4
https://developer.android.com/studio/build/multidex