Make background color lighter dynamically - wpf

I have a stackpanel with a wrappanel.
When the user hovers over the wrappanel I want the background to be a bit lighter than the current background, so it is clear for the user that he can click it.
The background is bound by my viewmodel and can change.
I use a Converter to convert an enum to a certain color.
<StackPanel x:Name="UserCallAlarmPanel" >
<StackPanel.Resources>
<Style x:Key="AlarmStyle" TargetType="{x:Type WrapPanel}">
<Setter Property="Background" Value="Transparent"/>
<Style.Triggers>
<DataTrigger Binding="{Binding IsMouseOver, ElementName=AlarmPanel}" Value="True" >
<Setter Property="Background" Value="{Binding CallStatus, Converter={StaticResource CallStatusBackgroundConverter}}"/>
<Setter Property="Opacity" Value="20"/>
</DataTrigger>
</Style.Triggers>
</Style>
</StackPanel.Resources>
<WrapPanel Name="AlarmPanel" Height="25" MouseLeftButtonDown="AlarmPanel_MouseLeftButtonDown" Style="{StaticResource AlarmStyle}">
<Viewbox>
<ContentControl Content="{DynamicResource alarm_icon}"/>
</Viewbox
</WrapPanel>
</StackPanel>
I tried to change to opacity but that doesn't work.

The valid values for Opacity are between 0 (fully transparent) and 1 (fully opaque). If you want 20% opacity, you need to use 0.2 for the value.

Related

Change expander background on mouse hover

I would like to change the expanders background color to a lighter variant on mouse hover. So I figured I use a trigger and a converter to convert the background color to a lighter variant on mouse over. I started simple and only implement the trigger. That works:
<StackPanel>
<StackPanel.Resources>
<Style TargetType="{x:Type Expander}">
<Style.Triggers>
<Trigger Property="Control.IsMouseOver" Value="True">
<Setter Property="Background" Value="Red"/>
</Trigger>
</Style.Triggers>
</Style>
</StackPanel.Resources>
<Expander Header="Header">
<StackPanel>
<TextBox Background="Transparent">Content</TextBox>
</StackPanel>
</Expander>
</StackPanel>
So I can achieve almost what I want. But I want to be able to set the color on the expander like this:
<Expander Header="Header" Background="Yellow">
The moment I add that the color switching stops working and the expander is always yellow. Why is that happening and how can I achieve my goal?
Edit: in my final application I will have an itemscontrol with multiple expanders whose background color is databound to my view model, so I think I cannot set the color in the style.
<ItemsControl ItemsSource="{Binding TestStepDescriptions}">
<ItemsControl.Resources>
<DataTemplate DataType="{x:Type localVMsTestEngines:AutomaticTestStepDescription}">
<Expander Background="{Binding StepStatus, Converter={StaticResource StepStatusToColorConverter}}">
regards,
Jef
You cannot set that color in the Expander directly if you use a Trigger.
Instead you have to do it like this:
<ItemsControl ItemsSource="{Binding TestStepDescriptions}">
<ItemsControl.Resources>
<DataTemplate DataType="{x:Type localVMsTestEngines:AutomaticTestStepDescription}">
<Expander >
<Expander.Style>
<Style TargetType="{x:Type Expander}">
<Setter Property="Background" Value="{Binding StepStatus, Converter={StaticResource StepStatusToColorConverter}}"/>
<Style.Triggers>
<Trigger Property="Control.IsMouseOver" Value="True">
<Setter Property="Background" Value="Red"/>
</Trigger>
</Style.Triggers>
</Style>
</Expander.Style>
</Expander>
Usage
<Expander Header="Header">

Styling DataGridCell correctly

This is a question following my previous problem, you can find it right there
So. Now I defined a DataGrid with a specific ElementStyle for each column (which just defines the TextBlocks inside in bold & white -- will come over this problem later)
So now I have two questions
First question (solved)
When I happen to set a background to my cell, it overrides the default style, and the background stays the same when the cell is highlighted.
One example of a style:
<!-- Green template for market-related -->
<ControlTemplate x:Key="Green" TargetType="{x:Type tk:DataGridCell}">
<Grid Background="Green">
<ContentPresenter
HorizontalAlignment="Center"
VerticalAlignment="Center" />
</Grid>
</ControlTemplate>
I'd naturally say that this is "normal" because I set the Grid's background to Green. I therefore tried it this way:
<!-- Light green template for sophis-related -->
<ControlTemplate x:Key="LightGreen" TargetType="{x:Type tk:DataGridCell}">
<Grid Background="LightGreen">
<Grid.Resources>
<Style TargetType="{x:Type Grid}">
<Style.Triggers>
<DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type tk:DataGridCell}},
Converter={StaticResource DebugConverter}}" Value="True">
<Setter Property="Grid.Background" Value="#FF3774FF" />
</DataTrigger>
</Style.Triggers>
</Style>
</Grid.Resources>
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</ControlTemplate>
This won't work either. As you can see I put a DebugConverter so I can check that the trigger is actually called, which is the case, but... Background does not change (and Snoop confirms this...)
Third try:
<!-- Light green template for sophis-related -->
<ControlTemplate x:Key="LightGreen" TargetType="{x:Type tk:DataGridCell}">
<ControlTemplate.Resources>
<Style TargetType="{x:Type tk:DataGridCell}">
<Setter Property="Background" Value="LightGreen" />
</Style>
</ControlTemplate.Resources>
<Grid>
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</ControlTemplate>
And... No background will be displayed (stays transparent)
So I think I am working in the wrong way here and I was wondering what should I do to JUST define the "not selected" template.
I would say that I may need to define a style BasedOn the "classic" style but, how would I do that? I tried to add TemplateBindings with no success
** EDIT: Solution**
As H B suggested in his answer, problem was coming from DependencyProperty Precedence, here's the solution:
<!-- Light green template for sophis-related -->
<ControlTemplate x:Key="LightGreen" TargetType="{x:Type tk:DataGridCell}">
<Grid>
<Grid.Resources>
<Style TargetType="{x:Type Grid}">
<Style.Triggers>
<DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type tk:DataGridCell}},
Converter={StaticResource DebugConverter}}" Value="True">
<Setter Property="Grid.Background" Value="#FF316AC5" />
</DataTrigger>
<DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type tk:DataGridCell}},
Converter={StaticResource DebugConverter}}" Value="False">
<Setter Property="Grid.Background" Value="LightGreen" />
</DataTrigger>
</Style.Triggers>
</Style>
</Grid.Resources>
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</ControlTemplate>
Second question
Now, let's speak Triggers.
Basically, what I want to do is to define specific Triggers to my ElementStyle so the font color is white if the cell's background is Red or Green (the only aim of this is to have a better readability as Red and Green are kinda dark, black font on dark background results in a nice fail :p )
Edit Seems like I'm not clear enough: the following style is the style applied to each item of the datagrid, through the property DataGridTextColumn.ElementStyle. Here is the code handling that:
void VolatilityDataGrid_AutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e)
{
DataGridTextColumn column = e.Column as DataGridTextColumn;
column.ElementStyle = s_boldCellStyle;
// Other stuff here...
}
Here is what I do:
<!-- Cell style for colored matrix-->
<Style x:Key="BoldCellStyle" TargetType="{x:Type TextBlock}">
<Style.Triggers>
<DataTrigger Binding="{Binding Background, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type tk:DataGridCell}}}"
Value="Red">
<Setter Property="Foreground" Value="White" />
</DataTrigger>
<DataTrigger Binding="{Binding Background, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type tk:DataGridCell}},
Converter={StaticResource DebugConverter}}"
Value="Green">
<Setter Property="Foreground" Value="White" />
</DataTrigger>
</Style.Triggers>
<Setter Property="FontWeight" Value="Bold"/>
</Style>
And... It doesn't work. Strangely, what goes through converter is ONLY transparent background colors. I am definitely missing something here!
BTW, I also tried with classic triggers, no success either, I use DataTriggers here so I can debug the binding values!
Now I've been stuck for more than three days on this and I'm starting to freak out... Hopefully the Stackoverflow community will save me :)
Thanks!
Edit
Okay, update.
I understood why my Trigger does not work. The Background actually set is on the Grid and NOT on the DataGridCell. It is therefore normal that I don't get any color set there.
However, I ran some tests and found out that when the binding is set, the TextBlock does not have any parent yet (Parent = null). Binding to a RelativeSource of type Grid will bind me to... The whole DataGrid items presenter.
I'm not sure what to do now, since it seems like that from the actual TextBlock style I can't reach the parent Grid and therefore cannot resolve what color should I display according to the background.
Also, I can't change the Font color in my ControlTemplate because the DataGrid wants a Style for each column, which overrides the template's style by default (see my previous question and its answer)
So... Stuck again I am!
Dependency Property Value Precedence
This:
<Grid Background="LightGreen">
<Grid.Resources>
<Style TargetType="{x:Type Grid}">
<!-- Trigger Stuff -->
</Style>
</Grid.Resources>
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
Needs to be:
<Grid>
<Grid.Resources>
<Style TargetType="{x:Type Grid}">
<Setter Property="Background" Value="LightGreen"/>
<!-- Trigger Stuff -->
</Style>
</Grid.Resources>
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
Not sure about your second question as of now, possibly a related problem, i would suggest setting TextElement.Foreground instead of Foreground for starters. Getting Transparent as value is not very helpful, what control template do you use for the DataGridCell? If it is custom, is the Background hooked up properly via a TemplateBinding?
This works as long as the Background property is used, so if you have a ControlTemplate which sets things internally you need to externalize that. A normal DataGrid example:
<DataGrid.CellStyle>
<Style TargetType="{x:Type DataGridCell}">
<Setter Property="Background" Value="LightGreen"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Content}" Value="Apple">
<Setter Property="Background" Value="Red"/>
</DataTrigger>
<DataTrigger Binding="{Binding Content}" Value="Tomato">
<Setter Property="Background" Value="Green"/>
</DataTrigger>
</Style.Triggers>
</Style>
</DataGrid.CellStyle>
<Style TargetType="TextBlock">
<Style.Triggers>
<DataTrigger Binding="{Binding Background, RelativeSource={RelativeSource AncestorType={x:Type DataGridCell}}}" Value="Red">
<Setter Property="Foreground" Value="White"/>
</DataTrigger>
<DataTrigger Binding="{Binding Background, RelativeSource={RelativeSource AncestorType={x:Type DataGridCell}}}" Value="Green">
<Setter Property="Foreground" Value="White"/>
</DataTrigger>
</Style.Triggers>
<Setter Property="FontWeight" Value="Bold"/>
</Style>
So if the CellStyle sets the ControlTemplate the properties need to be hooked up via TemplateBinding. e.g.
<DataGrid.CellStyle>
<Style TargetType="{x:Type DataGridCell}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type DataGridCell}">
<Grid Background="{TemplateBinding Background}">
<ContentPresenter />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="Background" Value="LightGreen"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Content}" Value="Apple">
<Setter Property="Background" Value="Red"/>
</DataTrigger>
<DataTrigger Binding="{Binding Content}" Value="Tomato">
<Setter Property="Background" Value="Green"/>
</DataTrigger>
</Style.Triggers>
</Style>
</DataGrid.CellStyle>
Do not do the triggering inside the template or it will get messy.

WPF Combobox Validation.ErrorTemplate error

I have a combobox that i need to edit its error template to show a red border when there is a validation error.
I am using the following style
<Style TargetType="{x:Type ComboBox}" >
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<DockPanel>
<Border BorderBrush="Red" BorderThickness="3">
<AdornedElementPlaceholder />
</Border>
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="FontFamily" Value="Segoe UI" />
<Setter Property="FontSize" Value="12" />
<Setter Property="VerticalAlignment" Value="Center" />
</Style>
The border never shows up when validation errors occur. Any tips what is going wrong?
The Style you posted works. You should check your binding, did you add ValidatesOnDataErrors=True and ValidatesOnExceptions=True to the binding of SelectedValue?
enter code heretry without the dock panel, that is uneuseful since it wraps jus one element. However, sicnecerely I don't wnow if it makes sense to wrap a textbox with a border, since it has already a border! You should try to change directly the colour of its border. You could try to use again the panel but then put the border around the panel ie:
Border BorderBrush="Red" BorderThickness="3"
DockPanel
AdornedElement
This makes more sense because the wrap panel has not its own border.
Use This.
<Style x:Key="textBoxStyle" TargetType="{x:Type telerik:RadMaskedTextBox}">
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="True">
<Setter Property="ToolTip" Value="{Binding RelativeSource={x:Static RelativeSource.Self}, Path=(Validation.Errors)[0].ErrorContent}"/>
<Setter Property="Control.BorderBrush" Value="Red" />
</Trigger>
</Style.Triggers>
</Style>
I don't like any of the responses here. Simply put, how do you change the border color for the error template for a ComboBox using Blend or not? It shouldn't be acceptable to draw another border around the existing border of the ComboBox. I've figured out how to creat a ControlTemplate in Blend but not a Validation Template.
I've come close with trying to make it appear like I've changed the actual border color, but that's not what I actually want. Suggestions? To complicate it a bit, I'd like to display a red asterisk outside of the right border of the control.
The following code is a close attempt, but it is actually drawing a border inside the ComboBox and if you look close, you can see that the border is 2 pixels wide when combined with the ComboBox border:
<DockPanel Name="myDockPanel">
<AdornedElementPlaceholder>
<Border BorderBrush="Blue" BorderThickness="1" CornerRadius="2" />
</AdornedElementPlaceholder>
<TextBlock Text="*" FontWeight="Bold" FontSize="14" Foreground="Red" DockPanel.Dock="Left" ToolTip="{Binding .CurrentItem}" />
</DockPanel>
I searched around some more and came up with a solution based on another article here: WPF - How to apply style to AdornedElementPlaceholder's AdornedElement?
<!-- This works -->
<ComboBox Name="comboBox1" Style="{StaticResource NewComboBoxStyle}" Validation.ErrorTemplate="{StaticResource comboBoxValidationTemplate}" />
<SolidColorBrush x:Key="MainBorderBrush">#FF91B3FF</SolidColorBrush>
<Style x:Key="NewComboBoxStyle" TargetType="{x:Type ComboBox}" BasedOn="{StaticResource myErrorTemplate}">
<Setter Property="BorderBrush" Value="{DynamicResource MainBorderBrush}" />
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="True">
<Setter Property="BorderBrush" Value="Blue" />
</Trigger>
</Style.Triggers>
</Style>
<!-- Sets ToolTip when Validation.HasError is True. -->
<Style TargetType="Control" x:Key="myErrorTemplate">
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="ToolTip"
Value="{Binding RelativeSource={x:Static RelativeSource.Self},
Path=(Validation.Errors).CurrentItem.ErrorContent}"/>
</Trigger>
</Style.Triggers>
</Style>
<ControlTemplate x:Key="comboBoxValidationTemplate">
<DockPanel Name="myDockPanel">
<AdornedElementPlaceholder/>
<TextBlock Text="*" FontWeight="Bold" FontSize="14" Foreground="Red" DockPanel.Dock="Left" ToolTip="{Binding .CurrentItem}" />
</DockPanel>
</ControlTemplate>

HorizontalContentAlignment of SelectedItem not stretching perfectly

I made a custom styled list in WPF:
<DataTemplate x:Key="SelectedTemplate">
<StackPanel Background="#FF4E4E4E" HorizontalAlignment="Stretch">
<TextBlock Text="{Binding Path=Title}" Foreground="#FFD80000" />
</StackPanel>
</DataTemplate>
<Style TargetType="{x:Type ListBoxItem}" x:Key="ContainerStyle">
<Setter Property="ContentTemplate"
Value="{StaticResource ItemTemplate}" />
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="ContentTemplate"
Value="{StaticResource SelectedTemplate}" />
</Trigger>
</Style.Triggers>
</Style>
...
<ListBox
Name="lbSongs"
DockPanel.Dock="Left"
ItemsSource="{Binding Path=SongDirectory}"
SelectedItem="{Binding Path=Song, Mode=TwoWay}"
Visibility="{Binding Path=ListVisibility}"
ItemContainerStyle="{StaticResource ContainerStyle}"
HorizontalContentAlignment="Stretch"
Width="180px" Background="#FF333333" />
I tried to make a custom style for the selected item. To make the selection bar stretch to the width of the ListBox, I set the ItemContainerStyle's HorizontalContentAlignment property to "Stretch". The problem is that it does not stretch fully, a tiny bar on the left still remains and the original (blue) selection bar is still visible there. See the screenshot:
How can I make it to stretch to full size? Or how can I style the original selection bar?
Thanks in advance.
Just set the Padding for the ListBoxItem to zero. That blue bar should disappear.
<Style TargetType="{x:Type ListBoxItem}" x:Key="ContainerStyle">
<Setter Property="Padding" Value="0"/>
...
</Style>
Another option is just to re-write the ControlTemplate for the ListBoxItem so that you'll have better control on how it looks like. But yeah, this may not be necessary in your case.

Not able to Style my WPF Controls

I am going crazy here! What am I missing and why it is not styling anything:
<Style x:Key="textBoxStyle" TargetType="{x:Type TextBox}">
<Style.Triggers>
<Trigger Property="IsFocused" Value="True">
<Setter Property="Background" Value="Red" />
</Trigger>
</Style.Triggers>
</Style>
<TextBox Width="100" Style="{StaticResource textBoxStyle}" Height="20" Background="Yellow" ></TextBox>
The above code does not do anything. It does not highlight the TextBox control!
This occurs because local values override style values. (Properties set directly on an element have very high precedence.) You are setting Background directly on the TextBox, so WPF is going, "Well, he normally wants textBoxStyle backgrounds to be Red when focused, but for this particular TextBox, he's said he specifically wants Background to be Yellow, so Yellow it is."
So the fix is to move the Yellow background to be part of the Style:
<Style x:Key="textBoxStyle" TargetType="{x:Type TextBox}">
<Setter Property="Background" Value="Yellow" />
<Style.Triggers>
<Trigger Property="IsFocused" Value="True">
<Setter Property="Background" Value="Red" />
</Trigger>
</Style.Triggers>
</Style>
and remove it from the TextBox:
<TextBox Width="100" Style="{StaticResource textBoxStyle}" Height="20" />
Define your Style before the TextBox or use DynamicResource instead of StaticResource

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