Question

I’m attempting to implement an animated drawable with the following…

<?xml version="1.0" encoding="UTF-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"
android:oneshot="false" >
<item android:drawable="@drawable/load_0000" android:duration="50" />
<item android:drawable="@drawable/load_0001" android:duration="50" />
<item android:drawable="@drawable/load_0002" android:duration="50" />
<item android:drawable="@drawable/load_0003" android:duration="50" />
<item android:drawable="@drawable/load_0004" android:duration="50" />
<item android:drawable="@drawable/load_0005" android:duration="50" />
<item android:drawable="@drawable/load_0006" android:duration="50" />
<item android:drawable="@drawable/load_0007" android:duration="50" />
<item android:drawable="@drawable/load_0008" android:duration="50" />
<item android:drawable="@drawable/load_0009" android:duration="50" />
</animation-list>

However, when I execute the following code I get thrown back a null pointer…

         ImageView img = (ImageView)findViewById(R.id.load_bar);
     img.setBackgroundResource(R.drawable.loader_animation); //null here.

Why? loader_animation is the files name and it is located in drawable/

Answer 1

The problem is that img is null:

Is there a View in the xml you have loaded with setContentView (or inflated and added to the contentView) that has the id load_bar ?

Mind you, just excisting in some XML, or loading it later does not work. findViewById finds current views!

If you have not loaded it, use an inflater.