How to convert text of a TextView to bitmap in Android?
Try this
Add to your onCreate()
tv1.setDrawingCacheEnabled(true);
Then in your onClick()
tv1.buildDrawingCache();
iv.setImageBitmap(tv1.getDrawingCache());
http://developer.android.com/reference/android/view/View.html#buildDrawingCache(boolean)
http://developer.android.com/reference/android/view/View.html#getDrawingCache(boolean)
[EDIT]
The problem you now have is that you are trying to enable the drawing cache before tv1 exists.
You should do this:
TextView tv1 = (TextView) findViewById(R.id.txtV);
tv1.setDrawingCacheEnabled(true);