Class SelectableCollectionViewModel<T>

View model class for representing a collection of objects that implements ISelectable. By default it only allows one item to be selected at a time and it will manage the IsSelected property of the items in the collection. If you want to allow multiple selections, set AllowMultipleSelections to true.

Inheritance

object

ViewModelBase

SelectableCollectionViewModel<T>

FilterableListViewModel<T>

SingleSelectListViewModel

Implements

INotifyPropertyChanged

Inherited Members

ViewModelBase.RaisePropertyChanged(string)

ViewModelBase.PropertyChanged

ViewModelBase.HasPropertyChangedSubscriber

ViewModelBase.DebuggingTag

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Benday.Presentation

Assembly: Benday.Presentation.dll

Syntax

public class SelectableCollectionViewModel<T> : ViewModelBase, INotifyPropertyChanged where T : class, ISelectable

Type Parameters

Name	Description
T

Constructors

SelectableCollectionViewModel()

Declaration

public SelectableCollectionViewModel()

SelectableCollectionViewModel(ObservableCollection<T>)

Initializes a new instance of the SelectableCollectionViewModel class with existing items or an existing ObservableCollection instance.

Declaration

public SelectableCollectionViewModel(ObservableCollection<T> values)

Parameters

Type	Name	Description
ObservableCollection<T>	values

Exceptions

Type	Condition
ArgumentNullException

SelectableCollectionViewModel(ObservableCollection<T>, T)

Initializes a new instance of the SelectableCollectionViewModel class with existing items or an existing ObservableCollection instance.

Declaration

public SelectableCollectionViewModel(ObservableCollection<T> values, T selectedItem)

Parameters

Type	Name	Description
ObservableCollection<T>	values
T	selectedItem	Item in the values collection that should be selected

Exceptions

Type	Condition
ArgumentNullException

Fields

ItemsPropertyName

Declaration

public readonly string ItemsPropertyName

Field Value

Type	Description
string

_Items

Declaration

protected ObservableCollection<T> _Items

Field Value

Type	Description
ObservableCollection<T>

Properties

AllowMultipleSelections

Gets or sets a value indicating whether multiple selections are allowed.

Declaration

public bool AllowMultipleSelections { get; set; }

Property Value

Type	Description
bool

BeforeSetSelectedItem

Gets or sets a delegate that is called before the selected item is changed. Return false from the delegate to cancel the selection change.

Declaration

public SelectableCollectionViewModel<T>.BeforeSetSelectedItemDelegate? BeforeSetSelectedItem { get; set; }

Property Value

Type	Description
SelectableCollectionViewModel<T>.BeforeSetSelectedItemDelegate

Count

Gets the number of items in the collection.

Declaration

public int Count { get; }

Property Value

Type	Description
int

HasOnItemSelectedSubscriber

Utility property to determine if the view model has a subscriber to the OnItemSelected event.

Declaration

public bool HasOnItemSelectedSubscriber { get; }

Property Value

Type	Description
bool

IgnoreRequestsToSetNullValuesAsSelected

Gets or sets a value indicating whether requests to set null values as the selected item should be ignored. When true, setting SelectedItem to null will have no effect. Default is false.

Declaration

public bool IgnoreRequestsToSetNullValuesAsSelected { get; set; }

Property Value

Type	Description
bool

IsEnabled

Gets or sets a value indicating whether this view model is enabled.

Declaration

public bool IsEnabled { get; set; }

Property Value

Type	Description
bool

IsValid

Gets or sets a value indicating whether this view model is valid. NOTE: this property does not do any validation, it is just a flag that can be used by the view.

Declaration

public bool IsValid { get; set; }

Property Value

Type	Description
bool

Items

Gets or sets the collection of items.

Declaration

public ObservableCollection<T> Items { get; protected set; }

Property Value

Type	Description
ObservableCollection<T>

SelectedItem

Gets or sets the selected item.

Declaration

public T? SelectedItem { get; set; }

Property Value

Type	Description
T

Methods

Add(T)

Adds an item to the collection.

Declaration

public void Add(T addThis)

Parameters

Type	Name	Description
T	addThis

Exceptions

Type	Condition
InvalidOperationException

Clear()

Clears the collection.

Declaration

public void Clear()

GetSelectedItems()

Gets the selected items.

Declaration

public List<T> GetSelectedItems()

Returns

Type	Description
List<T>	Selected items in a new instance of List

IndexOf(T)

Returns the index of the specified item in the collection.

Declaration

public int IndexOf(T item)

Parameters

Type	Name	Description
T	item	The item to locate.

Returns

Type	Description
int	The zero-based index of the item, or -1 if not found.

Initialize(IEnumerable<T>)

Resets the collection to the specified values.

Declaration

public virtual void Initialize(IEnumerable<T> values)

Parameters

Type	Name	Description
IEnumerable<T>	values

Move(int, int)

Moves an item from one position to another in the collection.

Declaration

public void Move(int draggedIndex, int targetIndex)

Parameters

Type	Name	Description
int	draggedIndex	The current index of the item to move.
int	targetIndex	The index to move the item to.

OnAfterMove(int, int)

Raises the AfterMove event.

Declaration

protected virtual void OnAfterMove(int draggedIndex, int targetIndex)

Parameters

Type	Name	Description
int	draggedIndex	The original index of the moved item.
int	targetIndex	The new index of the moved item.

OnItemPropertyChanged(object?, PropertyChangedEventArgs)

Declaration

protected virtual void OnItemPropertyChanged(object? sender, PropertyChangedEventArgs e)

Parameters

Type	Name	Description
object	sender
PropertyChangedEventArgs	e

Remove(T)

Removes an item from the collection.

Declaration

public void Remove(T removeThis)

Parameters

Type	Name	Description
T	removeThis

Exceptions

Type	Condition
InvalidOperationException

Events

AfterMove

Event raised after an item has been moved within the collection.

Declaration

public event EventHandler<MoveEventArgs<T>>? AfterMove

Event Type

Type	Description
EventHandler<MoveEventArgs<T>>

OnItemSelected

Event that is raised when an item is selected.

Declaration

public event ItemSelectedEventHandler<T>? OnItemSelected

Event Type

Type	Description
ItemSelectedEventHandler<T>

Implements

INotifyPropertyChanged