How can I change the transparency (alpha) of a view on pre-SDK-11 on Android?

Question

How can I change the transparency (alpha) of a view on pre-SDK-11 on Android?

Before you suggest using a background colour with some transparency, please note that this method does not include all elements in the view such as the text of a button or the child views of a view group.

Answer 1

Try using an AlphaAnimation : http://developer.android.com/reference/android/view/animation/AlphaAnimation.html

---

/* Have to use animation in order to get card faded. */

AlphaAnimation alpha = new AlphaAnimation(0.7F, 0.7F);
alpha.setDuration(0); // Make animation instant
alpha.setFillAfter(true); // Tell it to persist after the animation ends
view.startAnimation(alpha);

Answer 2

The ViewHelper of NineOldAndroids is what I use, it is a static helper class and a real gem! Many here recommend NineOldAndroids but I have seen no mention of the ViewHelper. It is really easy to use.

import com.nineoldandroids.view.ViewHelper;
...

ViewHelper.setAlpha(myView, .2f);

You can also use it to set other properties like x, y etc, very handy when setting up for animations or building your UI. Many thanks to Jake Wharton for sharing his work with the community!