Radio Button
Usage | Design-relevant Attributes | Related Controls
 |
Radio buttons provide users with a single choice from a set of alternative options |
| Figure 1: A radio button group | |
Usage
Radio buttons provide users with a single choice from a set of alternative options. They always appear in a group of at least two radio buttons. Therefore, you should define radio buttons only within the radio button group control, not as single elements.
A click on one choice selects the current choice and deselect the previous choice. Usually, always one radio button is checked. The Internet introduced one exception to this rule. In some cases, a radio button group can initially show up with no radio button checked.
Note: It is not possible to determine the horizontal spacing within a radio button group. If you need a different spacing than that supplied by the radio button group control, use single radio buttons and a grid layout control if applicable.
Arrangement and Design Alternatives
For details on the arrangement of radio buttons as well as design alternatives see Forms - Using Radio Buttons.
Design-relevant Attributes
Radio buttons have the disabled attribute. Set disabled to TRUE if users are not allowed to change their state temporarily. Attribute text sets the descriptive label text for a radio button.
For radio button groups there are two relevant attributes: You can determine which radio button is "on" in a group; set attribute selection to the id of the respective radio button. You can also set the column count for radio button groups (attribute columnCount).