Question: i need to add columns one by one in asp.net by click on plus symbol then one textbox and dropdown will appear dynamically and when click on minus that will disappear .

whenever user enter the data in textbox and dropdown and clickon plus symbol the that row will save in db and new empty textbox and dropdown will appear UI .this goes on.

How to acheive this?

Answer: 
You need to call mImage.setBounds(...); otherwise the canvas doesn't know where to draw the Drawable.
I think the main problem you have is that as soon as you start the thread with `.start();` the boolean `mRunning` is false and the thread will finish immediately. When you try to call `.setRunning(true);` after the thread has started it won't have any effect because the thread already finished.