How to uncheck the CheckBox, when limit exceeds in android?

Hello I am New to Android, My requirement is allow the user to check maximum 3 number of checkboxes. when user is trying to check fourth one 开发者_运维知识库should populate dailogue. Iam trying but the problem is fourth one is not unchecking...

can any one help me...

Regards Shiva.M

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Just uncheck the checkbox using the following code block:

     final CheckBox checkBox = (CheckBox) findViewById(R.id.checkbox_id);
     if (checkBox.isChecked()) {
         checkBox.setChecked(false);
     }