我终于设法解决了这个问题.原来，当我使用

I finally managed to solve the problem. Turned out that while I had enabled MultiDex in the gradle settings with

defaultConfig {
   multiDexEnabled true
   ...
}

并使用

depenencies {
   ...
   compile 'com.android.support:multidex:1.0.1'
   ...
}

我忘了用

<application
   ...
   android:name="android.support.multidex.MultiDexApplication"
   ...
>
   ...
</application>

添加该部分后，它现在可以在API级别19上运行.

After adding that part it now works on API level 19.