I need that when opening a ComboBox , all the elements are shown at once, without scrolling, but for some reason, on some computers, the sheet is half the size. (which is remarkable, this happens on laptops)

Here is the style

 <Style x:Key="comboBoxStyle" TargetType="{x:Type ComboBox}"> <Setter Property="SnapsToDevicePixels" Value="true"/> <Setter Property="OverridesDefaultStyle" Value="true"/> <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled"/> <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Disabled"/> <Setter Property="ScrollViewer.CanContentScroll" Value="False"/> <Setter Property="MinWidth" Value="120"/> <Setter Property="MinHeight" Value="20"/> <Setter Property="Foreground" Value="#FF00BB2B"/> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type ComboBox}"> <Grid> <ToggleButton Name="ToggleButton" Template="{StaticResource ComboBoxToggleButton}" Grid.Column="2" Focusable="false" IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}" ClickMode="Press"> </ToggleButton> <ContentPresenter Name="ContentSite" IsHitTestVisible="False" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" Margin="3,3,23,3" VerticalAlignment="Center" HorizontalAlignment="Left" /> <TextBox x:Name="PART_EditableTextBox" Style="{x:Null}" Template="{StaticResource ComboBoxTextBox}" HorizontalAlignment="Left" VerticalAlignment="Center" Margin="3,3,23,3" Focusable="True" Background="#FF00BB2B" Foreground="Green" Visibility="Hidden" IsReadOnly="{TemplateBinding IsReadOnly}"/> <Popup Name="Popup" Placement="Bottom" IsOpen="{TemplateBinding IsDropDownOpen}" AllowsTransparency="True" Focusable="False" PopupAnimation="Slide"> <Grid Name="DropDown" SnapsToDevicePixels="True" MinWidth="{TemplateBinding ActualWidth}" MaxHeight="{TemplateBinding MaxDropDownHeight}"> <Border x:Name="DropDownBorder" Background="#FF1B1B1B" BorderThickness="1" BorderBrush="#888888"/> <ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True"> <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" /> </ScrollViewer> </Grid> </Popup> </Grid> <ControlTemplate.Triggers> <Trigger Property="HasItems" Value="false"> <Setter TargetName="DropDownBorder" Property="MinHeight" Value="95"/> </Trigger> <Trigger Property="IsEnabled" Value="false"> <Setter Property="Foreground" Value="#888888"/> </Trigger> <Trigger Property="IsGrouping" Value="true"> <Setter Property="ScrollViewer.CanContentScroll" Value="false"/> </Trigger> <Trigger SourceName="Popup" Property="Popup.AllowsTransparency" Value="true"> <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0"/> <Setter TargetName="DropDownBorder" Property="Margin" Value="0,2,0,0"/> </Trigger> <Trigger Property="IsEditable" Value="true"> <Setter Property="IsTabStop" Value="false"/> <Setter TargetName="PART_EditableTextBox" Property="Visibility" Value="Visible"/> <Setter TargetName="ContentSite" Property="Visibility" Value="Hidden"/> </Trigger> </ControlTemplate.Triggers> </ControlTemplate> </Setter.Value> </Setter> </Style>

Please help me in solving this problem.

    1 answer 1

    You should be helped by the increase in MaxDropDownHeight . Please note that you cannot show as many elements as you like, as the window height is limited.

    Well, the combobox drop-down list will not be revealed to the full possible height, if your combo box is close to the edge of the screen: the maximum will seem only a piece to the bottom of the visible screen area.

    • 1) If the combo box opens from the bottom of the screen, then the sheet “crawls out” up to the free area =) 2) I always have the same number of elements, how can I calculate their total height? - Yaktens Teed
    • @YaktensTeed: 1) This is yes, but if the combo box is in the middle of the screen, and the list is longer than half the screen, then a problem arises. - VladD
    • @ YaktensTeed: 2) And all the elements of the same height? Create one element with Visibility = Hidden (but not Collapsed!), Wait until the mileage run has passed, and ask ActualHeight . Then multiply by the number of elements. - VladD
    • Everything, thank you, everything works - Jaktens Tied
    • @ YaktensTeed: Please! Glad that helped. - VladD