Question

I have to add more than one buttons on a LinearLayout. But I want to put those buttons say 5px apart. I could not find a way to set a margin of a Button. Any idea?

Answer 1

Use the layout_margin property of the button element. Does that not work?

<Button android:layout_margin="5px" (...)/>

Edit

When creating a button in java, LayoutParams is used to specify margins and so.

Button button = new Button();
(....)
params = new LinearLayout.LayoutParams();
params.leftMargin = 5;
(set params as you need)
parent.addView(button, params);

The LayoutParams you use must match the Layout you add your button in (see http://developer.android.com/reference/android/view/ViewGroup.LayoutParams.html). For a LinearLayout, use a LinearLayout.LayoutParams and set the *Margin fields accordingly.