跨度列导致NullPointerException

Question

I simply want to modify the span layout attribute of a textview (called t) in order to let it span 2 columns inside a table. I use the code

TextView t = new TextView(WineActivity.this);
t.setTextSize(15);
TableRow.LayoutParams params = (TableRow.LayoutParams) t.getLayoutParams();
params.span = 2; 
t.setLayoutParams(params);

Quite misteriously to me, the second line of the code generates a NullPointerException. Does anybody know why?

Answer 1

"params" is null.

I'm guessing that t.getLayoutParams is probably null as well, but seeing more code would help us.

Answer 2

The problem is you're calling (TableRow.LayoutParams) t.getLayoutParams(); but t doesn't generate LayoutParams until the program is already running and showing the page.

The simplest solution is just to create new params yourself.

TableRow.LayoutParams params = new TableRow.LayoutParams();
params.span = 3;
row.setLayoutParams(params);