syncfusion-wpf-dropdownbuttonadv

# Implementing WPF DropDownButtonAdv The `DropDownButtonAdv` is a WPF dropdown button control that displays a popup menu when the arrow is clicked. It supports menu items with icons, data binding, command binding, configurable popup direction, resizing, multiline text, and full theme support. **Assembly:** `Syncfusion.Shared.WPF` **Namespace:** `Syncfusion.Windows.Tools.Controls` **XAML Schema:** `xmlns:syncfusion="http://schemas.syncfusion.com/wpf"` ## When to Use This Skill - User wants a button that opens a dropdown list of options - User needs a WPF dropdown button with icons, checkable items, or grouped items - User asks about `DropDownButtonAdv`, `DropDownMenuGroup`, `DropDownMenuItem` - User needs MVVM binding for dropdown menu items or command binding - User needs to control popup direction, resizing, or multiline label - User asks how to handle dropdown open/close events or item click events ## Quick Start ```xaml xmlns:syncfusion="http://schemas.syncfusion.com/wpf" <syncfusion:DropDownButtonAdv Label="Country" SizeMode="Normal" SmallIcon="Images/flag.png"> <syncfusion:DropDownMenuGroup> <syncfusion:DropDownMenuItem HorizontalAlignment="Left" Header="India"> <syncfusion:DropDownMenuItem.Icon> <Image Source="Images/india.png"/> </syncfusion:DropDownMenuItem.Icon> </syncfusion:DropDownMenuItem> <syncfusion:DropDownMenuItem HorizontalAlignment="Left" Header="France"/> <syncfusion:DropDownMenuItem HorizontalAlignment="Left" Header="Germany"/> </syncfusion:DropDownMenuGroup> </syncfusion:DropDownButtonAdv> ``` ```csharp // C# equivalent DropDownButtonAdv button = new DropDownButtonAdv(); button.Label = "Country"; button.SizeMode = SizeMode.Normal; button.SmallIcon = new BitmapImage(new Uri("Images/flag.png", UriKind.RelativeOrAbsolute)); DropDownMenuGroup menu = new DropDownMenuGroup(); menu.Items.Add(new DropDownMenuItem { Header = "India", HorizontalAlignment = HorizontalAlignment.Left }); button.Content = menu; ``` ## Common Patterns | Goal | Approach | |---|---| | Static menu items | Declare `DropDownMenuItem` directly inside `DropDownMenuGroup` | | Dynamic items from data | Bind `DropDownMenuGroup.ItemsSource` + use `ItemTemplate` | | MVVM command on item click | Set `Command` + `CommandParameter` on `DropDownMenuItem` | | Popup opens below-left | `DropDirection="BottomLeft"` (default) | | Large button with label wrapping | `SizeMode="Large"` + `IsMultiLine="True"` | | Checkable items | `IsCheckable="True"` on `DropDownMenuItem` | | Custom UIElement in menu | Use `DropDownMenuGroup.MoreItems` property | | Scrollable long list | Set `MaxHeight` + `ScrollBarVisibility="Visible"` on group | | Resizable popup | `IsResizable="True"` on `DropDownMenuGroup` | ## Key Properties | Property | Type | Description | |---|---|---| | `Label` | `string` | Button text label | | `SizeMode` | `SizeMode` | Small / Normal / Large | | `SmallIcon` | `ImageSource` | Icon for Small and Normal modes | | `LargeIcon` | `ImageSource` | Icon for Large mode | | `IconTemplate` | `DataTemplate` | Vector/path icon template (overrides image icons) | | `IconTemplateSelector` | `DataTemplateSelector` | Conditionally select icon template | | `IconWidth` / `IconHeight` | `double` | Icon dimensions | | `DropDirection` | `DropDirection` | Popup position (default: BottomLeft) | | `IsMultiLine` | `bool` | Multi-line label (Large mode only) | | `DropDownMenuGroup.ItemsSource` | `IEnumerable` | Data-bound menu items | | `DropDownMenuGroup.IconBarEnabled` | `bool` | Show vertical icon bar | | `DropDownMenuGroup.ScrollBarVisibility` | `ScrollBarVisibility` | Scrollbar in popup | | `DropDownMenuGroup.IsResizable` | `bool` | Resize gripper on popup | | `DropDownMenuGroup.MoreItems` | `ObservableCollection<UIElement>` | Custom bottom items | | `DropDownMenuItem.IsCheckable` | `bool` | Allow check/uncheck | | `DropDownMenuItem.Command` | `ICommand` | MVVM command | | `DropDownMenuItem.CommandParameter` | `object` | Command parameter | --- ## Documentation and Navigation Guide ### Getting Started 📄 **Read:** [references/getting-started.md](references/getting-started.md) - Assembly reference (`Syncfusion.Shared.WPF`) - Add via designer, XAML, or C# - Setting `Label`, `SizeMode` (Small/Normal/Large) - SmallIcon, LargeIcon, IconWidth/IconHeight - IconTemplate and IconTemplateSelector - Basic menu items inline - Applying themes with SfSkinManager ### Dropdown Menu Items 📄 **Read:** [references/dropdown-menu-items.md](references/dropdown-menu-items.md) - `DropDownMenuGroup` as the container element - Declarative `DropDownMenuItem` with Header and Icon - `IconBarEnabled` (vertical icon strip) - `ScrollBarVisibility` for long item lists - `IsResizable` gripper for popup resize - `IsCheckable` / `IsChecked` for checkable items - `MoreItems` for custom UIElement additions - `IsMoreItemsIconTrayEnabled` ### Data Binding 📄 **Read:** [references/data-binding.md](references/data-binding.md) - Model and ViewModel pattern - Binding `DropDownMenuGroup.ItemsSource` - `ItemTemplate` with `DataTemplate` - Binding `DropDownMenuItem.Command` from ViewModel via `x:Reference` - Full MVVM example with `DelegateCommand<T>` - When to use data binding vs declarative items ### Command Binding 📄 **Read:** [references/command-binding.md](references/command-binding.md) - `Command` and `CommandParameter` on `DropDownMenuItem` - `DelegateCommand<T>` implementation - `CanExecute` and `CanPerformAction` toggle pattern - Binding to ViewModel commands in declarative XAML - Gotchas: scoping commands in DataTemplates ### Dropdown Behavior 📄 **Read:** [references/dropdown-behavior.md](references/dropdown-behavior.md) - `DropDirection` enum: Left, Right, BottomLeft, BottomRight, TopLeft, TopRight - Default direction is `BottomLeft` - `IsMultiLine` for wrapping long labels (Large mode only) - `FlowDirection` for RTL support ### Events & Appearance 📄 **Read:** [references/events-and-appearance.md](references/events-and-appearance.md) - `DropDownOpening` / `DropDownOpened` events (cancel support) - `DropDownClosing` / `DropDownClosed` events - `DropDownMenuItem.Click` event - `DropDownMenuItem.IsCheckedChanged` event - Editing control template in Expression Blend or Visual Studio - SfSkinManager themes + ThemeStudio custom themes