How to set a button's parameters programmatically

Set your attributes using the following code:

LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT);
button.setLayoutParams(params);
button.setGravity(Gravity.CENTER_HORIZONTAL);
button.setTextSize(32);

If you want to specify the text size units use:

button.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 32);

LayoutParams relates to the parent ViewGroup which will contain the view. So in your case it's a LinearLayout so you need to create parameters for that one. Here's what I'm talking about:

LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
    LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
lp.weight = 1f;

Button button = new Button(this);
button.setLayoutParams(lp);
button.setText("" + i);
((LinearLayout)dialog.findViewById(R.id.Buttons)).addView(button);

Use LayoutParams for the height, width and gravity with

LinearLayout.LayoutParams (int width, int height)

where you can use WRAP_CONTENT for the ints.

Then there are Button.setGravity() and Button.setTextSize() for the last two.

Hope this helps.