How to set only one RadioButton Can be selected at the time in RadioGroup

  <RadioGroup
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:id="@+id/radioGroup">
        <RadioButton
            android:layout_width="0dp"
            android:layout_weight="50"
            android:layout_height="wrap_content"
            android:text="Debit"
            android:id="@+id/rDebit"
            android:checked="false"
             />

        <RadioButton
            android:layout_width="0dp"
            android:layout_weight="50"
            android:layout_height="wrap_content"
            android:text="Credit"
            android:id="@+id/rCredit"
            android:checked="false" />

    </RadioGroup>

And in java file

 RadioGroup radioGroup;



radioGroup = (RadioGroup) findViewById(R.id.radioGroup);

And when to do something

 if (radioGroup.getCheckedRadioButtonId() == R.id.rCredit)
{
// do something
}

I have noticed that single selection does not work without setting id to radio buttons.

             <RadioGroup
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal">

                <RadioButton
                    android:id="@+id/expenseRadio"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:checked="true"
                    android:text="@string/expense" />

                <RadioButton
                    android:id="@+id/incomeRadio"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/income" />
            </RadioGroup>

It's not working because of TableRow inside RadioGroup. All RadioButtons are not grouped together because of TableRow between them.

RadioButton should be the direct child of RadioGroup, Otherwise grouping does not work.

Just change your code like this it will work :

        <RadioGroup
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/RGroup">

            <RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Abdominal"
                android:id="@+id/Abdominal"/>
            <RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Arm"
                android:id="@+id/Arm"/>
            <RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Back"
                android:id="@+id/Back" />                                        

            <RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Chest"
                android:id="@+id/Chest"/>
            <RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Leg"
                android:id="@+id/Leg"/>
            <RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Shoulder"
                android:id="@+id/Shoulder"/>

        </RadioGroup>

Hope this helps. :)