Class LinearSelector<T>
A linear range view that allows selection of a single option from a typed list of options.
public class LinearSelector<T> : LinearRangeViewBase<T, T>, IDisposable, ISupportInitializeNotification, ISupportInitialize, IOrientation, IValue<T>, IValue, IDesignableType Parameters
TThe data type of the options.
- Inheritance
-
LinearRangeViewBase<T, T>LinearSelector<T>
- Implements
-
IValue<T>
- Derived
- Inherited Members
- Extension Methods
Remarks
Exposes the current selection through Value. When T is a
reference type, null unambiguously represents "no selection". When
T is a value type, Value is default(T) when no
option is selected — which can be indistinguishable from a legitimately selected default value
(e.g. 0 for int). To test for empty selection unambiguously for both
reference and value types, use SelectedIndex, which is null
only when nothing is selected.
To switch the current selection programmatically, set Value or SelectedIndex. To observe selection changes, subscribe to ValueChanged.
Constructors
- LinearSelector()
Initializes a new instance of LinearSelector<T>.
- LinearSelector(List<T>?, Orientation)
Initializes a new instance of LinearSelector<T>.
Properties
- SelectedIndex
Gets or sets the index of the currently selected option, or null if no option is selected. This is the unambiguous "no selection" surface for both reference and value types (compare with Value, where
default(T)for value types may collide with a legitimately selected option).
- Value
Gets or sets the value.
Methods
- EnableForDesign()
Loads demo data suitable for a designer preview: a single-select LinearSelector<T> of T-shirt sizes (XS through XXL) with "M" preselected. Only populated when
Tis string; for any other type, the view is left untouched and false is returned.
- OnSelectionChanged()
Called by the base when the selected indices have changed due to user input. Concrete subclasses must compute their Value from the current selection and raise ValueChanged / ValueChangedUntyped.