Why isn't my vector drawable scaling as expected?

Question

I am attempting to use vector drawables in my Android app. From http://developer.android.com/training/material/drawables.html (emphasis mine):

In And

Answer 1

AppCompat 23.2 introduces vector drawables for all devices running Android 2.1 and above. The images scale correctly, irregardless of the width/height specified in the vector drawable's XML file. Unfortunately, this implementation is not used in API level 21 and above (in favor of the native implementation).

The good news is that we can force AppCompat to use its implementation on API levels 21 and 22. The bad news is that we have to use reflection to do this.

First of all, make sure you're using the latest version of AppCompat, and that you have enabled the new vector implementation:

android {
  defaultConfig {
    vectorDrawables.useSupportLibrary = true
  }
}

dependencies {
    compile 'com.android.support:appcompat-v7:23.2.0'
}

Then, call useCompatVectorIfNeeded(); in your Application's onCreate():

private void useCompatVectorIfNeeded() {
    int sdkInt = Build.VERSION.SDK_INT;
    if (sdkInt == 21 || sdkInt == 22) { //vector drawables scale correctly in API level 23
        try {
            AppCompatDrawableManager drawableManager = AppCompatDrawableManager.get();
            Class inflateDelegateClass = Class.forName("android.support.v7.widget.AppCompatDrawableManager$InflateDelegate");
            Class vdcInflateDelegateClass = Class.forName("android.support.v7.widget.AppCompatDrawableManager$VdcInflateDelegate");

            Constructor constructor = vdcInflateDelegateClass.getDeclaredConstructor();
            constructor.setAccessible(true);
            Object vdcInflateDelegate = constructor.newInstance();

            Class args[] = {String.class, inflateDelegateClass};
            Method addDelegate = AppCompatDrawableManager.class.getDeclaredMethod("addDelegate", args);
            addDelegate.setAccessible(true);
            addDelegate.invoke(drawableManager, "vector", vdcInflateDelegate);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }
}

Finally, make sure you're using app:srcCompat instead of android:src to set your ImageView's image:

Your vector drawables should now scale correctly!