Error while trying to set custom shape as background of widget

I want to set the background of the standard TextView in an Android project to a cust开发者_JS百科om shape. The shape is defined as follows:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="rectangle" >

    <gradient android:type="radial"
              android:angle="90"
              android:startColor="#FF1EFFFF"
              android:endColor="#B01E90FF"
              android:centerColor="#201E90FF"
              android:centerX="0.5"
              android:centerY="1.0" />

</shape>

I try to set the custom shape by calling the setBackgroundResource() method on the textView.

TextView main = (TextView) findViewById(R.id.mainTextView);
main.setBackgroundResource(R.drawable.gradient);

However, when I deploy this project on either a real device or on the Android Emulator, it won't start, and show this error:

ERROR/AndroidRuntime(4369): java.lang.RuntimeException: Unable to start activity ComponentInfo{org.android.gradienttest/org.android.gradienttest.MainActivity}: android.view.InflateException: Binary XML file line #7: Error inflating class <unknown>

Trying to set the drawable by first getting it as a shape results in the same error. By getting it as a shape I mean:

Resources res = getResources();
Shape shape = res.getDrawable(R.drawable.gradient);

But as I said, this results in the same error... I know it gives the error when I try to load the shape, but the problem is I don't know why... So could anybody give me some help on this one? It must be a trivial mistake, as there isn't that much code involved...

It appears that I forgot to add an attribute to my XML file. The attribute was android:gradientRadius="180". By adding this attribute the gradient was being drawn correctly. Thanks user639183!

CenterX and centerY are supposed to be integers. This page has a good listing of what all of the parameters will take.