Unable to change background for a Wpf toolkit autocompletebox? - wpf

How should i change the background of the wpftoolkit autocompletebox.? I tried by subscribing to enabledchanged event and changed the background of the control which is not changing at all.Can any body help.
<WpfToolkit:AutoCompleteBox x:Name="txtBxSearch" Background="White" IsTextCompletionEnabled="True" MinimumPrefixLength="0" FilterMode="Contains" Height="24" Width="150" KeyDown="txtBxSearch_KeyDown" >
<WpfToolkit:AutoCompleteBox.TextBoxStyle>
<Style TargetType="TextBox">
<Setter Property="FocusVisualStyle" Value="{x:Null}"/>
<Setter Property="FocusManager.FocusedElement" Value="{Binding RelativeSource={RelativeSource Self}}"/>
</Style>
</WpfToolkit:AutoCompleteBox.TextBoxStyle>
</WpfToolkit:AutoCompleteBox>

You can do this in XAML:
<toolkit:AutoCompleteBox
ToolTip="Enter the path of an assembly."
x:Name="tbAssembly" Height="27" Width="200"
Populating="tbAssembly_Populating"
>
<toolkit:AutoCompleteBox.Style>
<Style TargetType="toolkit:AutoCompleteBox">
<Style.Triggers>
<DataTrigger Binding="{Binding ElementName=tbAssembly, Path=IsEnabled}" Value="True">
<Setter Property="Background" Value="Yellow" />
<Setter Property="Foreground" Value="Red" />
</DataTrigger>
<DataTrigger Binding="{Binding ElementName=tbAssembly, Path=IsEnabled}" Value="False">
<Setter Property="Background" Value="Black" />
<Setter Property="Foreground" Value="Yellow" />
</DataTrigger>
</Style.Triggers>
</Style>
</toolkit:AutoCompleteBox.Style>
</toolkit:AutoCompleteBox>

Related

Value cannot be null. Parameter name: from WPF button binding datatrigger

I've been struggeling with this issue today when as soon as I try to bind a data trigger on a button I get this issue and I can't find our the issue. The button is contained in a listview which is bound to a dataset.
There is my button code:
<Button
Grid.Row="1"
Grid.Column="0"
Click="BtnAddToCart_Click"
MinWidth="230">
<Button.Style>
<Style TargetType="{x:Type Button}">
<Setter Property="Visibility" Value="Hidden"/>
<Setter Property="Margin" Value="7,5,0,0"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=OrderQty, Converter={StaticResource GreaterThanZero}}" Value="True">
<Setter Property="Visibility" Value="Visible"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
<Button.Template>
<ControlTemplate>
<WrapPanel HorizontalAlignment="Stretch" VerticalAlignment="Stretch" >
<WrapPanel.Style>
<Style TargetType="{x:Type WrapPanel}">
<Setter Property="Background" Value="#ec3c42"/>
<Setter Property="TextBlock.Foreground" Value="White"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="White"/>
<Setter Property="Cursor" Value="Hand"></Setter>
<Setter Property="TextBlock.Foreground" Value="#ec3c42"></Setter>
</Trigger>
</Style.Triggers>
</Style>
</WrapPanel.Style>
<WrapPanel.Resources>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="Padding" Value="10,10" />
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="FontSize" Value="15"/>
</Style>
</WrapPanel.Resources>
<TextBlock VerticalAlignment="Center" HorizontalAlignment="Center" Text="Ajouter aux Commandes"></TextBlock>
<fa:FontAwesome Visibility="Hidden" VerticalAlignment="Center" HorizontalAlignment="Right" Icon="check">
<fa:FontAwesome.Triggers>
<DataTrigger Binding="{Binding Path=ShowAsChecked}" Value="true">
<Setter Property="Visibility" Value="Visible"></Setter>
</DataTrigger>
</fa:FontAwesome.Triggers>
</fa:FontAwesome>
</WrapPanel>
</ControlTemplate>
</Button.Template>
</Button>
The issue seems to happen when I add this piece of code:
<fa:FontAwesome.Triggers>
<DataTrigger Binding="{Binding Path=ShowAsChecked}" Value="true">
<Setter Property="Visibility" Value="Visible"></Setter>
</DataTrigger>
</fa:FontAwesome.Triggers>
When I remove the trigger the code run as expected.
Even when I bind it to a property that is working on a different level it doesn't work.
I tried changing the binding to:
Binding="{Binding Path=OrderQty, Converter={StaticResource GreaterThanZero}}
and it's still giving me the error. I tried to look up some code example but didn't find anything about that issue (since the error is pretty common it's hard to tell what is going on).
Try
<fa:FontAwesome Visibility="Hidden" VerticalAlignment="Center" HorizontalAlignment="Right" Icon="check">
<fa:FontAwesome.Style>
<Style TargetType="fa:FontAwesome">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=ShowAsChecked}" Value="true">
<Setter Property="Visibility" Value="Visible"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</fa:FontAwesome.Style>
</fa:FontAwesome>

How can I highlight the cell which contains the error?

I have a DataGrid with four columns for which I have defined a style as well as a triggered style for the case the user enters an invalid value.
<Style TargetType="{x:Type DataGridRow}">
<Setter Property="FontSize" Value="16"/>
<Setter Property="FontFamily" Value="ArialMT"/>
<Setter Property="Height" Value="24"/>
<Setter Property="VerticalAlignment" Value="Center"/>
<Setter Property="ValidationErrorTemplate">
<Setter.Value>
<ControlTemplate>
<Grid>
<Ellipse Width="12" Height="12" Fill="Red" Stroke="Black" StrokeThickness="0.5"/>
<TextBlock FontWeight="Bold" Padding="4,0,0,0" Margin="0" VerticalAlignment="Top" Foreground="White" Text="!" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="BorderBrush" Value="Red"/>
<Setter Property="IsEnabled" Value="True" />
<Setter Property="ToolTip" Value="{Binding RelativeSource={x:Static RelativeSource.Self}, Path=(Validation.Errors)[0].ErrorContent}"/>
</Trigger>
</Style.Triggers>
</Style>
This works well and the complete DataGridRow is marked as faulty because I used this in the XAML:
<DataGrid.RowValidationRules>
<local:CycleValidationRule ValidationStep="UpdatedValue" />
</DataGrid.RowValidationRules>
Now I want to highlight the DataGridCell with the invalid value explictely additionally (setting the background colour). Hence, I defined another style:
<Style x:Key="cycleErrStyle" TargetType="{x:Type TextBlock}">
<Setter Property="Background" Value="Magenta"/>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true" >
<Setter Property="Background" Value="Red" />
<Setter Property="Foreground" Value="White" />
</Trigger>
</Style.Triggers>
</Style>
but this doesn't work.
When I set <Trigger Property="Validation.HasError" Value="false" > to false, the style affects. It seems as if the Validation.HasError property has been reset after validation for the grid's row.
In the XAML I defined this:
<DataGridTextColumn x:Name="TagCycle" Header="Cycle" Binding="{Binding Mode=TwoWay, Path=RawTag.Cycle, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}"
ElementStyle="{StaticResource ResourceKey=cycleErrStyle}" />
How can I highlight the invalid cell additionally to marking the row as faulty?
You could use a DataTrigger that binds to the Validation.HasError attached property of the parent DataGridRow:
<Style x:Key="cycleErrStyle" TargetType="{x:Type TextBlock}">
<Setter Property="Background" Value="Magenta"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=(Validation.HasError), RelativeSource={RelativeSource AncestorType=DataGridRow}}" Value="true" >
<Setter Property="Background" Value="Red" />
<Setter Property="Foreground" Value="White" />
</DataTrigger>
</Style.Triggers>
</Style>

WPF DataGrid: How do you set the style of the first row only?

I've tried searching for the answer, but the question that's been posted here has not been answered.
I've tried some complicated XAML, but it's never worked. The code below grays out all rows if the first row is selected. I need to gray out the first row only, regardless of which row index is selected.
<TextBlock.Style>
<Style TargetType="TextBlock">
<Setter Property="Foreground" Value="Black"/>
<Setter Property="FontStyle" Value="Normal"/>
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Path=SelectedIndex, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type DataGrid}}}" Value="0"/>
</MultiDataTrigger.Conditions>
<Setter Property="Foreground" Value="Gray"/>
<Setter Property="FontStyle" Value="Italic"/>
</MultiDataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
Would anyone be able to help?
Thanks.
You can use the AlternationCount property found on all ItemsControls (ref ListBox).
<DataGrid ItemsSource="{Binding Items}"
AlternationCount="2147483647"
...
>
<DataGrid.ItemContainerStyle>
<Style TargetType="DataGridRow">
<Style.Triggers>
<Trigger Property="ItemsControl.AlternationIndex" Value="0">
<Setter Property="Foreground" Value="Gray"/>
<Setter Property="FontStyle" Value="Italic"/>
</Trigger>
</Style.Triggers>
</Style>
</DataGrid.ItemContainerStyle>
...
</DataGrid>
EDIT
<DataGrid ItemsSource="{Binding Items}"
AlternationCount="2"
VirtualizingStackPanel.IsVirtualizing="False">
...
>
<DataGrid.ItemContainerStyle>
<Style TargetType="DataGridRow">
<Style.Triggers>
<Trigger Property="ItemsControl.AlternationIndex" Value="1">
<Setter Property="Background" Value="Gray"/>
</Trigger>
<DataTrigger
Binding="{Binding RelativeSource={RelativeSource Mode=PreviousData}}"
Value="{x:Null}">
<Setter Property="Foreground" Value="Gray"/>
<Setter Property="FontStyle" Value="Italic"/>
</DataTrigger>
</Style.Triggers>
</Style>
</DataGrid.ItemContainerStyle>
...
</DataGrid>

Change image and textblock foreground on TabItem = IsSelected

I have some TabItems, each one containg one image and a textblock. Here is the code:
<TabItem.Header>
<ContentControl>
<ContentControl.Template>
<ControlTemplate>
<StackPanel x:Name="sp" Orientation="Horizontal">
<Image x:Name="img" Source="img0.png"/>
<TextBlock x:Name="tb" Text="Tab1" VerticalAlignment="Center" Foreground="Green"/>
</StackPanel>
<ControlTemplate.Triggers>
<Trigger Property="TabItem.IsSelected" Value="True">
<Setter TargetName="img" Property="Source" Value="img1.png" />
<Setter TargetName="tb" Property="Foreground" Value="Red" />
<Setter Property="FontWeight" Value="Bold"/>
</Trigger>
<Trigger SourceName="sp" Property="IsMouseOver" Value="True">
<Setter TargetName="img" Property="Source" Value="img1.png" />
<Setter TargetName="tb" Property="Foreground" Value="Red" />
<Setter Property="FontWeight" Value="Bold"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</ContentControl.Template>
</ContentControl>
What I'm trying to achieve is to change the image's source and textblock's foreground value when the TabItem is selected. The IsMouseOver behaviour is working properly but the TabItem.IsSelected is not working as expected.
Basically this code is not doing what I'm thinking it should do:
<Trigger Property="TabItem.IsSelected" Value="True">
<Setter TargetName="img" Property="Source" Value="img1.png" />
<Setter TargetName="tb" Property="Foreground" Value="Red" />
<Setter Property="FontWeight" Value="Bold"/>
Please share your opinion.
Thank you.
You are trying to reach the IsSelected property of the TabItem from the TabItem.Header and that can't be accomplished with an ordinary Trigger. Instead, you need to use a DataTrigger so that you can Bind to the IsSelected property with a RelativeSource Binding:
<DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType=
{x:Type TabItem}}}" Value="True">
<Setter TargetName="img" Property="Source"
Value="/WpfApplication1;component/Images/Tulips.jpg" />
<Setter TargetName="tb" Property="Foreground" Value="Red" />
<Setter Property="TextElement.FontWeight" Value="Bold"/>
</DataTrigger>

How do I override the WPF GroupBox disabled (i.e. Gray) color for its header?

I have followed the advice of previous answers for setting a global GroupBox style that includes a HeaderTemplate. The style works great for when the affected GroupBox objects are enabled. When the affected GroupBox objects are disabled, I can only get the border color to change. I don't want the default Gray color when the GroupBox objects are disabled. My GroupBox style is shown below:
<!-- This is the color brush I am trying to set on the header text -->
<SolidColorBrush x:Key="moDisabledFGColor" Color="DarkBlue" Opacity="0.5" />
<Style TargetType="{x:Type GroupBox}">
<Setter Property="BorderThickness" Value="2" />
<Setter Property="BorderBrush" Value="{StaticResource moFGColor}"/>
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="Foreground" Value="{StaticResource moFGColor}" />
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock x:Name="HeaderText" Text="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type GroupBox}}, Path=Header}" FontWeight="Bold"
Foreground="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type GroupBox}}, Path=Foreground}" />
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding Path=IsEnabled, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type GroupBox}}}" Value="False">
<Setter TargetName="HeaderText" Property="Foreground" Value="{StaticResource moDisabledFGColor}"/>
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="BorderBrush" Value="{StaticResource moDisabledFGColor}" />
<Setter Property="Foreground" Value="{StaticResource moDisabledFGColor}" />
</Trigger>
</Style.Triggers>
</Style>

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