android set checked radio button in radiogroup code example

Example 1: android radiobutton setchecked

radioGroup.check(R.id.radioButtonId);

Example 2: how to set radio button checked in android programmatically

In your layout you can add android:checked="true" to CheckBox you want to be selected.

Or programmatically, you can use the setChecked method defined in the checkable interface:

RadioButton b = (RadioButton) findViewById(R.id.option1);
b.setChecked(true);