I would like to create a custom WPF control that inherits from comboBox. So far, I created my project and changed the inheritance from Control to ComboBox since this is what I want. I tried to update the visual by going into Generic.xaml and change the template from the default one to a copy of a normal combo box (I used Blend to create a copy of the template and copied it). This is where it starts to crash.
For now I get the error
Cannot find the static member ‘MaxDropDownHeightProperty’ on the type ‘Control’.
I do not get any grooved line showing where the error is but I have an idea where it is.
I think I understand that this mean that the template still thinks it’s a template of ‘Control’ type, but how do I change that into ComboBox.
Regards,
Edit : I am fully aware that copying the template of the combox box isn’t really usefull if I am going to use exactly that same, but that fact is that I would like change it evenually, hence the need to.
Here is the General.xaml and my code page. It’s pretty long
SearchComboBox.vb :
Public Class SearchComboBox
Inherits ComboBox
Public Shared ReadOnly OriginalItemSourceProperty As DependencyProperty
Private _OriginalItemSource As System.Collections.IEnumerable
Shared Sub New()
'This OverrideMetadata call tells the system that this element wants to provide a style that is different than its base class.
'This style is defined in Themes\Generic.xaml
DefaultStyleKeyProperty.OverrideMetadata(GetType(SearchComboBox), New FrameworkPropertyMetadata(GetType(SearchComboBox)))
Dim md As New FrameworkPropertyMetadata()
SearchComboBox.OriginalItemSourceProperty = DependencyProperty.Register("OriginalSource", GetType(System.Collections.IEnumerable), GetType(SearchComboBox), md)
End Sub
Public Sub New()
MyBase.IsEditable = True
End Sub
Public Property OriginalSource As System.Collections.IEnumerable
Get
Return CType(GetValue(SearchComboBox.OriginalItemSourceProperty), System.Collections.IEnumerable)
End Get
Set(ByVal value As System.Collections.IEnumerable)
SetValue(SearchComboBox.OriginalItemSourceProperty, value)
MyBase.ItemsSource = value
End Set
End Property
End Class
Generic.xaml :
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero"
xmlns:local="clr-namespace:SeachComboBox">
<Style TargetType="{x:Type local:SearchComboBox}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Grid x:Name="Placement" SnapsToDevicePixels="True">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Popup x:Name="PART_Popup" AllowsTransparency="True" Grid.ColumnSpan="2" IsOpen="{Binding IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}}" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Placement="Bottom">
<Microsoft_Windows_Themes:SystemDropShadowChrome x:Name="Shdw" Color="Transparent" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=Placement}">
<Border x:Name="DropDownBorder" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
<ScrollViewer x:Name="DropDownScrollViewer">
<Grid RenderOptions.ClearTypeHint="Enabled">
<Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
<Rectangle x:Name="OpaqueRect" Fill="{Binding Background, ElementName=DropDownBorder}" Height="{Binding ActualHeight, ElementName=DropDownBorder}" Width="{Binding ActualWidth, ElementName=DropDownBorder}"/>
</Canvas>
<ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Contained" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Grid>
</ScrollViewer>
</Border>
</Microsoft_Windows_Themes:SystemDropShadowChrome>
</Popup>
<Microsoft_Windows_Themes:ListBoxChrome x:Name="Border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderFocused="{TemplateBinding IsKeyboardFocusWithin}"/>
<TextBox x:Name="PART_EditableTextBox" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" IsReadOnly="{Binding IsReadOnly, RelativeSource={RelativeSource TemplatedParent}}" Margin="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}">
<TextBox.Style>
<Style TargetType="{x:Type TextBox}">
<Setter Property="OverridesDefaultStyle" Value="True"/>
<Setter Property="AllowDrop" Value="True"/>
<Setter Property="MinWidth" Value="0"/>
<Setter Property="MinHeight" Value="0"/>
<Setter Property="FocusVisualStyle" Value="{x:Null}"/>
<Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TextBox}">
<ScrollViewer x:Name="PART_ContentHost" Background="{TemplateBinding Background}" Focusable="False" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"/>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="Background" Value="#FFEDDDDD"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</TextBox.Style>
</TextBox>
<ToggleButton Grid.Column="1" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}">
<ToggleButton.Style>
<Style TargetType="{x:Type ToggleButton}">
<Setter Property="OverridesDefaultStyle" Value="True"/>
<Setter Property="IsTabStop" Value="False"/>
<Setter Property="Focusable" Value="False"/>
<Setter Property="ClickMode" Value="Press"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Microsoft_Windows_Themes:ButtonChrome x:Name="Chrome" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}" RoundCorners="False" SnapsToDevicePixels="True" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}">
<Path x:Name="Arrow" Data="M0,0L3.5,4 7,0z" Fill="Black" HorizontalAlignment="Center" Margin="0,1,0,0" VerticalAlignment="Center"/>
</Microsoft_Windows_Themes:ButtonChrome>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="RenderPressed" TargetName="Chrome" Value="True"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Fill" TargetName="Arrow" Value="#FFEDDDDD"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ToggleButton.Style>
</ToggleButton>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsKeyboardFocusWithin" Value="True">
<Setter Property="Foreground" Value="Black"/>
</Trigger>
<Trigger Property="IsDropDownOpen" Value="True">
<Setter Property="RenderFocused" TargetName="Border" Value="True"/>
</Trigger>
<Trigger Property="HasItems" Value="False">
<Setter Property="Height" TargetName="DropDownBorder" Value="95"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="Background" Value="#FFEDDDDD"/>
</Trigger>
<Trigger Property="IsGrouping" Value="True">
<Setter Property="ScrollViewer.CanContentScroll" Value="False"/>
</Trigger>
<Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="True">
<Setter Property="Margin" TargetName="Shdw" Value="0,0,5,5"/>
<Setter Property="Color" TargetName="Shdw" Value="#71000000"/>
</Trigger>
<Trigger Property="CanContentScroll" SourceName="DropDownScrollViewer" Value="False">
<Setter Property="Canvas.Top" TargetName="OpaqueRect" Value="{Binding VerticalOffset, ElementName=DropDownScrollViewer}"/>
<Setter Property="Canvas.Left" TargetName="OpaqueRect" Value="{Binding HorizontalOffset, ElementName=DropDownScrollViewer}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
1 Answer