title: How to use "disableAlpha" with EditText / How to change attribute in AttributeSet
body: <p>I want my Edittext to grey-out less or more than standard when disabled with editTxtV.setEnabled(false).
  Oviously the disableAlpha-Property does exactly this.
  But using android:disabledAlpha="2.0" like this in layout.xml </p>
  
  <pre><code>&lt;EditText android:inputType="numberDecimal" android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/EditTextV" android:text="1" android:disabledAlpha="2.0" &gt;&lt;/EditText&gt;
  </code></pre>
  
  <p>do not change the behaviour at all.</p>
  
  <p>Hot do I correctly change "how much to grey out"?</p>
  
  <p>Sebastian</p>
  
  <p>PS: 
  One idea is to make a custom View extending EditText. In the constructor I get attrs AttributeSet and give that back to super.constructor, but how to change the disableAlpha-attribute on its way through my constructor?</p>