A material design radio button.

Used to select between a number of mutually exclusive values. When one radio button in a group is selected, the other radio buttons in the group cease to be selected. The values are of type T, the type parameter of the Radio class. Enums are commonly used for this purpose.

The radio button itself does not maintain any state. Instead, when the state of the radio button changes, the widget calls the onChanged callback. Most widget that use a radio button will listen for the onChanged callback and rebuild the radio button with a new groupValue to update the visual appearance of the radio button.

Requires one of its ancestors to be a Material widget.

See also:



Radio({Key key, T value, T groupValue, ValueChanged<T> onChanged, Color activeColor })

Creates a material design radio button.



activeColor Color

The color to use when this radio button is selected.

groupValue → T

The currently selected value for this group of radio buttons.

onChanged ValueChanged<T>

Called when the user selects this radio button.

value → T

The value represented by this radio button.

hashCode int

The hash code for this object.

read-only, inherited
key Key

Controls how one widget replaces another widget in the tree.

final, inherited
runtimeType Type

A representation of the runtime type of the object.

read-only, inherited


createState() → _RadioState<T>

Creates the mutable state for this widget at a given location in the tree.

createElement() StatefulElement

Creates a StatefulElement to manage this widget's location in the tree.

debugFillDescription(List<String> description) → void

Add additional information to the given description for use by toString.

@mustCallSuper, @protected, inherited
noSuchMethod(Invocation invocation) → dynamic

Invoked when a non-existent method or property is accessed.

toString() String

Returns a string representation of this object.

toStringShort() String

A short, textual description of this widget.



operator ==(other) bool

The equality operator.