Suppose your application have a some views which are in blinking mode or need some thing like which Fade-in and Fade-out continuously..

At that time if you are using images then you can set its alpha (transparency) easily by using BitmapDrawable.

But if you are using TextView then how to set alpha to content of TextView, so here is solution:

Create object of TextView :
TextView tvAlphaTest = new TextView(context);

To set alpha:
tvAlphaTest.setTextColor(tvAlphaTest.getTextColors().withAlpha(alpha));

we used tvAlphaTest.getTextColors() to get recent color..