How can I get the correct DisplayMetrics from an AppWidget in Android?

问题

I need to determine the screen density at runtime in an Android AppWidget. I've set up an HDPI emulator device (avd). If set up a regular executable project, and insert this code into the onCreate method:

DisplayMetrics dm = getResources().getDisplayMetrics();
Log.d("MyTag", "screen density " + dm.densityDpi);

This outputs "screen density 240" as expected.

However, if I set up an AppWidget project, and insert this code into the onUpdate method:

DisplayMetrics dm = context.getResources().getDisplayMetrics();
Log.d("MyTag", "screen density " + dm.densityDpi);

This outputs "screen density 160". I noticed, hooking up the debugger, that the mDefaultDisplay member of the Resources object here is null in the AppWidget case.

Similarly, if I get a resource at runtime using the Resources object obtained from context.getResources() in the AppWidget, it returns the wrong resource based on screen density. For instance, I have a 60x60px drawable for mdpi, and an 80x80 drawable for hdpi. If I get this Drawable object using context.getResources().getDrawable(...), it returns the 60x60 version.

Is there any way to correctly deal with resources at runtime from the context of an AppWidget?

Thanks!

回答1:

This feels like a bug. If you can create a sample project that demonstrates the error, post an issue on the Android issue tracker. If you think of it, add a comment here pointing to the issue.

来源：https://stackoverflow.com/questions/2643198/how-can-i-get-the-correct-displaymetrics-from-an-appwidget-in-android