ComboBox Class
This API supports the .NET Framework infrastructure and is not intended to be used directly from your code.
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Represents a selection control that combines a non-editable text box and a drop-down containing a list box that allows users to select an item from a list.
Assembly: System.Windows (in System.Windows.dll)
XMLNS for XAML: Not mapped to an xmlns.
The ComboBox type exposes the following members.
| Name | Description | |
|---|---|---|
 | ActualHeight | Gets the rendered height of a FrameworkElement. (Inherited from FrameworkElement.) |
| ActualWidth | Gets the rendered width of a FrameworkElement. (Inherited from FrameworkElement.) |
| AllowDrop | Gets or sets a value that determines whether this UIElement can be a drop target for purposes of drag-and-drop operations. (Inherited from UIElement.) |
| Background | (Inherited from Control.) |
| BorderBrush | (Inherited from Control.) |
| BorderThickness | (Inherited from Control.) |
| CacheMode | Gets or sets a value that indicates that rendered content should be cached when possible. (Inherited from UIElement.) |
| CharacterSpacing | (Inherited from Control.) |
| Clip | Gets or sets the Geometry used to define the outline of the contents of a UIElement. (Inherited from UIElement.) |
| Cursor | Infrastructure. Gets or sets the cursor image that displays while the pointer is over a FrameworkElement. (Inherited from FrameworkElement.) |
| DataContext | Gets or sets the data context for a FrameworkElement when it participates in data binding. (Inherited from FrameworkElement.) |
 | DefaultStyleKey | (Inherited from Control.) |
| DesiredSize | Gets the size that this UIElement computed during the measure pass of the layout process. (Inherited from UIElement.) |
| Dispatcher | Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.) |
| DisplayMemberPath | Gets or sets the name or path of the property that is displayed for each data item. (Inherited from ItemsControl.) |
| FlowDirection | Gets or sets the direction that text and other user interface elements flow within any parent element that controls their layout. (Inherited from FrameworkElement.) |
| FontFamily | (Inherited from Control.) |
| FontSize | (Inherited from Control.) |
| FontStretch | (Inherited from Control.) |
| FontStyle | (Inherited from Control.) |
| FontWeight | (Inherited from Control.) |
| Foreground | (Inherited from Control.) |
| Height | Gets or sets the suggested height of a FrameworkElement. (Inherited from FrameworkElement.) |
| HorizontalAlignment | Gets or sets the horizontal alignment characteristics that are applied to a FrameworkElement when it is composed in a layout parent, such as a panel or items control. (Inherited from FrameworkElement.) |
| HorizontalContentAlignment | (Inherited from Control.) |
| IsDropDownOpen | Gets or sets a value that indicates whether the drop-down portion of the combo box is currently open. |
| IsEditable | Gets a value that indicates whether the user can edit text in the text box portion of a combo box. This property always returns false. |
| IsEnabled | (Inherited from Control.) |
| IsHitTestVisible | Gets or sets whether the contained area of this UIElement can return true values for hit testing. (Inherited from UIElement.) |
| IsSelectionBoxHighlighted | Gets a value that indicates whether the SelectionBoxItem is highlighted. |
| IsSynchronizedWithCurrentItem | Gets or sets a value that indicates whether the Selector should keep the SelectedItem synchronized with the current item in the Items property. (Inherited from Selector.) |
| IsTabStop | (Inherited from Control.) |
| ItemContainerGenerator | Gets the ItemContainerGenerator associated with this ItemsControl. (Inherited from ItemsControl.) |
| ItemContainerStyle | Gets or sets the style applied to the container generated for each item in the combo box. |
| Items | Gets the collection used to generate the content of the control. (Inherited from ItemsControl.) |
| ItemsPanel | Gets or sets the template that defines the panel that controls the layout of items. (Inherited from ItemsControl.) |
| ItemsSource | Gets or sets a collection used to generate the content of the ItemsControl. (Inherited from ItemsControl.) |
| ItemTemplate | Gets or sets the DataTemplate used to display each item. (Inherited from ItemsControl.) |
| Language | Gets or sets localization/globalization language information that applies to a FrameworkElement. (Inherited from FrameworkElement.) |
| Margin | Gets or sets the outer margin of a FrameworkElement. (Inherited from FrameworkElement.) |
| MaxDropDownHeight | Gets or sets the maximum height of the drop-down that lists combo box items. |
| MaxHeight | Gets or sets the maximum height constraint of a FrameworkElement. (Inherited from FrameworkElement.) |
| MaxWidth | Gets or sets the maximum width constraint of a FrameworkElement. (Inherited from FrameworkElement.) |
| MinHeight | Gets or sets the minimum height constraint of a FrameworkElement. (Inherited from FrameworkElement.) |
| MinWidth | Gets or sets the minimum width constraint of a FrameworkElement. (Inherited from FrameworkElement.) |
| Name | Gets or sets the identifying name of the object. When a XAML processor creates the object tree from XAML markup, run-time code can refer to the XAML-declared object by this name. (Inherited from FrameworkElement.) |
| Opacity | Gets or sets the degree of the object's opacity. (Inherited from UIElement.) |
| OpacityMask | Gets or sets the brush used to alter the opacity of regions of this object. (Inherited from UIElement.) |
| Padding | (Inherited from Control.) |
| Parent | Gets the parent object of this FrameworkElement in the object tree. (Inherited from FrameworkElement.) |
| Projection | Gets or sets the perspective projection (3-D effect) to apply when rendering this UIElement. (Inherited from UIElement.) |
| RenderSize | Gets the final render size of a UIElement. (Inherited from UIElement.) |
| RenderTransform | Gets or sets transform information that affects the rendering position of a UIElement. (Inherited from UIElement.) |
| RenderTransformOrigin | Gets or sets the origin point of any possible render transform declared by RenderTransform, relative to the bounds of the UIElement. (Inherited from UIElement.) |
| Resources | Gets the locally defined resource dictionary. In XAML, you can establish resource items as child object elements of a frameworkElement.Resources property element, through XAML implicit collection syntax. (Inherited from FrameworkElement.) |
| SelectedIndex | Gets or sets the index of the selected item. (Inherited from Selector.) |
| SelectedItem | Gets or sets the selected item. (Inherited from Selector.) |
| SelectedValue | Gets or sets the value of the selected item, obtained by using the SelectedValuePath. (Inherited from Selector.) |
| SelectedValuePath | Gets or sets the property path that is used to get the SelectedValue property of the SelectedItem property. (Inherited from Selector.) |
| SelectionBoxItem | Gets the item displayed in the selection box. |
| SelectionBoxItemTemplate | Gets the template applied to the selection box content. |
| Style | Gets or sets an instance Style that is applied for this object during rendering. (Inherited from FrameworkElement.) |
| TabIndex | (Inherited from Control.) |
| TabNavigation | (Inherited from Control.) |
| Tag | Gets or sets an arbitrary object value that can be used to store custom information about this object. (Inherited from FrameworkElement.) |
| Template | (Inherited from Control.) |
| Triggers | Gets the collection of triggers for animations that are defined for a FrameworkElement. (Inherited from FrameworkElement.) |
| UseLayoutRounding | Gets or sets a value that determines whether rendering for the object and its visual subtree should use rounding behavior that aligns rendering to whole pixels. (Inherited from UIElement.) |
| UseOptimizedManipulationRouting | Gets or sets a value that indicates whether the system should handle input events or whether the FrameworkElement should handle input events. (Inherited from FrameworkElement.) |
| VerticalAlignment | Gets or sets the vertical alignment characteristics that are applied to a FrameworkElement when it is composed in a parent object such as a panel or items control. (Inherited from FrameworkElement.) |
| VerticalContentAlignment | (Inherited from Control.) |
| Visibility | Gets or sets the visibility of a UIElement. A UIElement that is not visible does not render and does not communicate its desired size to layout. (Inherited from UIElement.) |
| Width | Gets or sets the width of a FrameworkElement. (Inherited from FrameworkElement.) |
| Name | Description | |
|---|---|---|
 | AddHandler | Adds a routed event handler for a specified routed event, adding the handler to the handler collection on the current element. Specify handledEventsToo as true to have the provided handler be invoked for routed event that had already been marked as handled by another element along the event route. (Inherited from UIElement.) |
| ApplyTemplate | (Inherited from Control.) |
| Arrange | Positions child objects and determines a size for a UIElement. Parent objects that implement custom layout for their child elements should call this method from their layout override implementations to form a recursive layout update. (Inherited from UIElement.) |
 | ArrangeOverride | Arranges and sizes the combo box control and its contents. (Overrides FrameworkElement::ArrangeOverride(Size).) |
| CaptureMouse | Sets touch capture to a UIElement. (Inherited from UIElement.) |
| CheckAccess | Determines whether the calling thread has access to this object. (Inherited from DependencyObject.) |
| ClearContainerForItemOverride | Removes all templates, styles, and bindings for the object displayed as a ComboBoxItem. (Overrides Selector::ClearContainerForItemOverride(DependencyObject, Object).) |
| ClearValue | Clears the local value of a dependency property. (Inherited from DependencyObject.) |
| Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
| Finalize | Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.) |
| FindName | Retrieves an object that has the specified identifier name. (Inherited from FrameworkElement.) |
| Focus | (Inherited from Control.) |
| GetAnimationBaseValue | Returns any base value established for a Windows Phone dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject.) |
| GetBindingExpression | Retrieves the BindingExpression for a dependency property where a binding is established. (Inherited from FrameworkElement.) |
| GetContainerForItemOverride | Retrieves an empty combo box item. (Overrides ItemsControl::GetContainerForItemOverride().) |
| GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
| GetTemplateChild | (Inherited from Control.) |
| GetType | Gets the Type of the current instance. (Inherited from Object.) |
| GetValue | Returns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject.) |
| InvalidateArrange | Invalidates the arrange state (layout) for a UIElement. After the invalidation, the UIElement will have its layout updated, which will occur asynchronously. (Inherited from UIElement.) |
| InvalidateMeasure | Invalidates the measurement state (layout) for a UIElement. (Inherited from UIElement.) |
| IsItemItsOwnContainerOverride | Determines whether the specified item is (or is eligible to be) its own item container. (Overrides ItemsControl::IsItemItsOwnContainerOverride(Object).) |
| Measure | Updates the DesiredSize of a UIElement. Typically, objects that implement custom layout for their layout children call this method from their own MeasureOverride implementations to form a recursive layout update. (Inherited from UIElement.) |
| MeasureOverride | Provides the behavior for the Measure pass of Windows Phone layout. Classes can override this method to define their own Measure pass behavior. (Inherited from FrameworkElement.) |
| MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
| OnApplyTemplate | Builds the visual tree for the ComboBox when a new template is applied. (Overrides Selector::OnApplyTemplate().) |
| OnCreateAutomationPeer | Returns a ComboBoxAutomationPeer for use by the Windows Phone automation infrastructure. (Overrides UIElement::OnCreateAutomationPeer().) |
| OnDoubleTap | (Inherited from Control.) |
| OnDragEnter | (Inherited from Control.) |
| OnDragLeave | (Inherited from Control.) |
| OnDragOver | (Inherited from Control.) |
| OnDrop | (Inherited from Control.) |
| OnDropDownClosed | Raises the DropDownClosed event. |
| OnDropDownOpened | Raises the DropDownOpened event. |
| OnGotFocus | Provides handling for the GotFocus event. (Overrides Control::OnGotFocus(RoutedEventArgs).) |
| OnHold | (Inherited from Control.) |
| OnItemsChanged | Updates the current selected item when the Items collection has changed. (Inherited from Selector.) |
| OnKeyDown | Provides handling for the KeyDown event. (Overrides Control::OnKeyDown(KeyEventArgs).) |
| OnKeyUp | (Inherited from Control.) |
| OnLostFocus | Provides handling for the LostFocus event. (Overrides Control::OnLostFocus(RoutedEventArgs).) |
| OnLostMouseCapture | (Inherited from Control.) |
| OnManipulationCompleted | (Inherited from Control.) |
| OnManipulationDelta | (Inherited from Control.) |
| OnManipulationStarted | (Inherited from Control.) |
| OnMouseEnter | Provides handling for the MouseEnter event that occurs when the user’s finger enters this control. (Overrides Control::OnMouseEnter(MouseEventArgs).) |
| OnMouseLeave | Provides handling for the MouseLeave event that occurs when the user’s finger leaves the combo box. (Overrides Control::OnMouseLeave(MouseEventArgs).) |
| OnMouseLeftButtonDown | Provides handling for the MouseLeftButtonDown event that occurs when the user touches the screen within the bounds the combo box. (Overrides Control::OnMouseLeftButtonDown(MouseButtonEventArgs).) |
| OnMouseLeftButtonUp | (Inherited from Control.) |
| OnMouseMove | (Inherited from Control.) |
| OnMouseRightButtonDown | (Inherited from Control.) |
| OnMouseRightButtonUp | (Inherited from Control.) |
| OnMouseWheel | Infrastructure. Provides handling for the MouseWheel event. (Overrides Control::OnMouseWheel(MouseWheelEventArgs).) |
| OnTap | (Inherited from Control.) |
| OnTextInput | (Inherited from Control.) |
| OnTextInputStart | (Inherited from Control.) |
| OnTextInputUpdate | (Inherited from Control.) |
| PrepareContainerForItemOverride | Prepares the specified element to display the specified item. (Overrides Selector::PrepareContainerForItemOverride(DependencyObject, Object).) |
| ReadLocalValue | Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.) |
| ReleaseMouseCapture | Removes touch capture from a UIElement. After this call, typically no object holds touch capture. (Inherited from UIElement.) |
| RemoveHandler | Removes the specified routed event handler from this UIElement. (Inherited from UIElement.) |
| SetBinding | Attaches a binding to a FrameworkElement, using the provided binding object, and returns a BindingExpressionBase for possible later use. (Inherited from FrameworkElement.) |
| SetValue | Sets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject.) |
| ToString | Returns a string that represents the current object. (Inherited from Object.) |
| TransformToVisual | Returns a transform object that can be used to transform coordinates from the UIElement to the specified object. (Inherited from UIElement.) |
| UpdateLayout | Ensures that all positions of child objects of a UIElement are properly updated for layout. (Inherited from UIElement.) |
| Name | Description | |
|---|---|---|
 | BindingValidationError | Occurs when a data validation error is reported by a binding source. (Inherited from FrameworkElement.) |
| DoubleTap | Occurs when a DoubleTap gesture is committed while over this UIElement. (Inherited from UIElement.) |
| DropDownClosed | Occurs when the drop-down portion of the combo box closes. |
| DropDownOpened | Occurs when the drop-down portion of the combo box opens. |
| GotFocus | Occurs when a UIElement receives focus. (Inherited from UIElement.) |
| Hold | Occurs when a Hold gesture is committed while over this UIElement. (Inherited from UIElement.) |
| IsEnabledChanged | (Inherited from Control.) |
| KeyDown | Occurs when a keyboard key is pressed while the UIElement has focus. (Inherited from UIElement.) |
| KeyUp | Occurs when a keyboard key is released while the UIElement has focus. (Inherited from UIElement.) |
| LayoutUpdated | Occurs when the layout of the Windows Phone visual tree changes. (Inherited from FrameworkElement.) |
| Loaded | Occurs when a FrameworkElement has been constructed and added to the object tree. (Inherited from FrameworkElement.) |
| LostFocus | Occurs when a UIElement loses focus. (Inherited from UIElement.) |
| LostMouseCapture | Occurs when the UIElement loses touch capture. (Inherited from UIElement.) |
| ManipulationCompleted | Occurs when a manipulation and inertia on the UIElement is complete. (Inherited from UIElement.) |
| ManipulationDelta | Occurs when the input device changes position during a manipulation. (Inherited from UIElement.) |
| ManipulationStarted | Occurs when an input device begins a manipulation on the UIElement. (Inherited from UIElement.) |
| MouseEnter | Occurs when a screen tap occurs within the bounding area of a UIElement. (Inherited from UIElement.) |
| MouseLeave | Occurs when a touch event occurs outside the bounding area of a UIElement. (Inherited from UIElement.) |
| MouseLeftButtonDown | Occurs when a UIElement is tapped. (Inherited from UIElement.) |
| MouseLeftButtonUp | Occurs when the finger is lifted off of a UIElement (or while a UIElement holds touch capture). (Inherited from UIElement.) |
| MouseMove | Occurs when the coordinate position of the finger on the screen while touching a UIElement (or while a UIElement holds touch capture). (Inherited from UIElement.) |
| MouseWheel | Infrastructure. Occurs when the user rotates the mouse wheel while the mouse pointer is over a UIElement, or the UIElement has focus. (Inherited from UIElement.) |
| SelectionChanged | Occurs when the currently selected item changes. (Inherited from Selector.) |
| SizeChanged | Occurs when either the ActualHeight or the ActualWidth properties change value on a FrameworkElement. (Inherited from FrameworkElement.) |
| Tap | Occurs when a Tap gesture is committed while over this UIElement. (Inherited from UIElement.) |
| TextInput | Occurs when a UI element gets text in a device-independent manner. (Inherited from UIElement.) |
| TextInputStart | Occurs when a UI element initially gets text in a device-independent manner. (Inherited from UIElement.) |
| TextInputUpdate | Occurs when text continues to be composed via an input method editor (IME). (Inherited from UIElement.) |
| Unloaded | Occurs when this object is no longer connected to the main object tree. (Inherited from FrameworkElement.) |
| Name | Description | |
|---|---|---|
  | IsDropDownOpenProperty | Identifies the IsDropDownOpen dependency property. |
| IsSelectionActiveProperty | Identifies the IsSelectionActive attached property. |
| ItemContainerStyleProperty | Identifies the ItemContainerStyle dependency property. |
| MaxDropDownHeightProperty | Identifies the MaxDropDownHeight dependency property. |
| Name | Description | |
|---|---|---|
  | ISupportInitialize::BeginInit | Signals the object that initialization is starting. (Inherited from Selector.) |
| ISupportInitialize::EndInit | Signals the object that initialization is complete. (Inherited from Selector.) |
The text box either displays the current selection or is empty if there is no selected item.
 Note: |
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If you populate a combo box with items that inherit from UIElement, the selected item can only appear in the visual tree one time. This means if an item is selected, it will appear in the selection box, and not in the drop-down list of items. When it is no longer the selected item, it will reappear in the drop-down list. If items do not inherit from UIElement, they can appear in both the selection box and the drop-down list at the same time. |
ComboBox is an ItemsControl, which means it has an associated item container, ComboBoxItem, which contains individual pieces of content in the control. A ComboBoxItem is created for each item in a collection and can be retrieved, whether or not you create it explicitly. You can retrieve ComboBoxItem container objects by using the ItemContainerGenerator property associated with the ComboBox control. You populate the ComboBox by using the Items or ItemsSource properties.
You can retrieve the combo box's selected item by using the SelectedItem property, or retrieve the index of the selected item by using the SelectedIndex property.
Customizing the ComboBox Control
You can apply a style to each item displayed in the ComboBox by setting the ItemContainerStyle property.
To apply the same property settings to multiple ComboBox controls, use the Style property. To change the visual structure and visual behavior of a ComboBox, copy and modify its default style and template.
Dependency properties for this control might be set by the default style of the control. If a dependency property for a ComboBox is set by its default style, the property might change from its default value when the ComboBox appears in the application. For more information, see Dependency properties for Windows Phone 8.
| Note: |
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Setting a visual property will only have an effect if that property is both present in ComboBox control's default template and is set by using a TemplateBinding. |
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