In the C1TaskDialog.RadioButtons Collection Editor dialog box you can add radio buttons to the C1TaskDialog dialog box and customize the text displayed next to each button. To access the RadioButtons Collection Editor, select the Edit Radio Buttons link from the C1TaskDialog control's Tasks menu, context menu, or below the Properties window, or click the ellipses button next to the RadioButtons property in the Properties window.

The RadioButtons Collection Editor appears similar to the following:

You can select an item in the Members list or, using the buttons below the list, you can add and remove radio buttons or copy existing radio buttons. For each radio button you can set or change the Text that appears next to the button, enable or disable the button, and set or change the name of the button.

If you add a radio button the dialog box with your changes will be automatically previewed. To close the preview click elsewhere in Visual Studio.