Android widget with transparent background: added image should not be transparent

Question

I developed a native widget for Android 4.0.

Tha Layout is like this:

Framelayout <- alpha 0.7
  LinearLayout
    TextView
    ImageView <- alpha 1.0
    TextView

The main element is the image. I like to have the background of the widget transparent, but not the image. So I set alpha of the FrameLayout to 0.7 and alpha of the ImageView to 1.0 in the xml file. In the code I set the image with setImageViewBitmap.

Now the widget has some transparency like I wanted. But the Image has also some transparency. But I should be opaque. How can I set solve this?

Answer 1

Instead of using alpha(since it fades everything inside the parent) you can use background colour with transparency.

For 0.7 alpha, which means 70% white you can use (B3 is 70% value):

android:background="#B3FFFFFF"

So you will have a 30% transparent background and your ImageView will be visible as normal.

If you insist doing it by alpha, you must exlude your ImageView from the View which you set alpha value.