How to use IsEnabledChanged event on element inside style? - wpf

I have an element specified inside a style. I need the codebehind to know when IsEnabled changes on one of the elements (the Border in this simplified example), so initially I just set the event like normal:
<UserControl.Resources>
<Style x:Key="TypedValueHelper" TargetType="ContentControl">
<Style.Triggers>
<DataTrigger Binding="{Binding Type, RelativeSource={RelativeSource FindAncestor, AncestorType=UserControl}}"
Value="Markdown">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<Border x:Name="BorderThing"
IsEnabledChanged="BorderThing_IsEnabledChanged"/>
</DataTemplate>
</Setter.Value>
</Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</UserControl.Resources>
Then Visual Studio complained at me and I remembered that you can't set events directly on an element in a style, so I fixed it:
<UserControl.Resources>
<Style x:Key="BorderThing" TargetType="Border">
<EventSetter Event="IsEnabledChanged" Handler="BorderThing_IsEnabledChanged"/>
</Style>
<Style x:Key="TypedValueHelper" TargetType="ContentControl">
<Style.Triggers>
<DataTrigger Binding="{Binding Type, RelativeSource={RelativeSource FindAncestor, AncestorType=UserControl}}"
Value="Markdown">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<Border x:Name="BorderThing"/>
</DataTemplate>
</Setter.Value>
</Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</UserControl.Resources>
But now it's telling me The event 'IsEnabledChanged' is not a RoutedEvent ☹
How do I get my event?

Related

WPF Select ComboBox text style based on variable

I have a ComboBox and I'd like to be able to change the style of the text inside the ComboBoxItem based on an attribute of the ComboBoxItem.
<ComboBox ItemsSource="{Binding Countries}">
<ComboBox.ItemTemplate>
<DataTemplate>
<ContentControl Content="{Binding}" Focusable="False">
<ContentControl.Style>
<Style TargetType="{x:Type ContentControl}">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock Text="{Binding Name}" Style="{StaticResource MyStyle}" />
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</ContentControl.Style>
</ContentControl>
</DataTemplate>
</ComboBox.ItemTemplate>
I've been trying to set the TextBlock Style from MyStyle to a different one if the Country's attribute IsWestern is true, but I am not managing. I figure I need a Trigger somewhere, but I can't figure it out and added a variety, but none worked so far.
use DataTrigger to change ContentTemplate:
<Style TargetType="{x:Type ContentControl}">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock Text="{Binding Name}" Style="{StaticResource MyStyle}" />
</DataTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsWestern}" Value="True">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock Text="{Binding Name}" Style="{StaticResource WesternStyle}" />
</DataTemplate>
</Setter.Value>
</Setter>
</DataTrigger>
</Style.Triggers>
</Style>
alternatively include <DataTrigger Binding="{Binding Path=IsWestern}" Value="True"> in TextBlock Style (MyStyle) and change required TextBlock properties there:
<Style x:Key="MyStyle" TargetType="TextBlock">
<Setter Property="LineStackingStrategy" Value="BlockLineHeight"></Setter>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsWestern}" Value="True">
<Setter Property="Padding" Value="20,0,0,0"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>

XAML custom text in TextBlock

Good afternoon,
I´m binding a list of doubles (Latlng) to an ItemsControl and in a TextBlock I want to make a custom text when the list binded has a count of 0. With the code I have the TextBlock is empty when the ItemsSource of the ItemsControl is that list.
What am I doing wrong?
Btw the list Latlng is a property of a class.
<ItemsControl Name="icLatLng" ItemsSource="{Binding Latlng}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock FontFamily="Arial" FontSize="14">
<TextBlock.Style>
<Style>
<Setter Property="TextBlock.Text" Value="{Binding}"></Setter>
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl}, Path=Items.Count}" Value="0">
<Setter Property="TextBlock.Text" Value="—"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
Thanks in advance.
Welcome to SO.
ItemsControl.ItemTemplate is the template that gets applied to each element in the Items list the control is bound to. If there are no items to begin with, then it won't be created, so anything you do in it won't be seen.
I suspect what you're really trying to do is replace the look of the entire control when the list is empty. If so, you can do that by applying a new template to the ItemsControl itself using a DataTrigger on the HasItems property:
<ItemsControl Name="icLatLng" ItemsSource="{Binding Latlng}">
<ItemsControl.Style>
<Style TargetType="{x:Type ItemsControl}" BasedOn="{StaticResource {x:Type ItemsControl}}">
<Style.Triggers>
<DataTrigger Binding="{Binding HasItems, RelativeSource={RelativeSource Self}}" Value="False">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ItemsControl}">
<TextBlock Text="-" />
</ControlTemplate>
</Setter.Value>
</Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</ItemsControl.Style>
</ItemsControl>

How to change TreeViewItem background color according to property of bound data?

I have a TreeView where the data is bound to generic derived wrapper classes over my data hierarchy.
My bound wrapper classes include added fields like "IsHilighted" and "IsExpanded".
I would like to change the background of any TreeViewItem according to its bound data property "IsHiglighted". I would like to set the color of Hilighted item to the same (or lighter) color as the default Selected item background color.
Ideally, I would like to not modify existing XAML... I mean being able to eventually add the behavior through code.
UPDATE
I have found a partial solution: I had to add triggers as defined below. Code included below.
<Style TargetType="TreeViewItem">
<Setter Property="IsExpanded" Value="{Binding Path=IsExpanded}"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsHilighted}" Value="true">
<Setter Property="Background" Value="SlateBlue"></Setter>
<Setter Property="Opacity" Value="160"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>
Still not resolved: How could I bind the color of Hilighted item (see partial solution above) to the "Selected" TreeViewItem background color, i.e. replace "SlateBlue" on partial solution to binding to existing selected item style background color ?
Original TreeView XAML code:
<TreeView Name="TreeViewSelectScopeStudy" MinHeight="24" Margin="7" ItemsSource="{Binding Path=TvItemRootPssTreeViewRoot.ChildsView}" Height="Auto"
VerticalAlignment="Stretch"
VirtualizingStackPanel.IsVirtualizing="True"
VirtualizingStackPanel.VirtualizationMode="Recycling">
<TreeView.Resources>
<Style TargetType="TreeViewItem">
<Setter Property="IsExpanded" Value="{Binding Path=IsExpanded}"/>
</Style>
<SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Red" />
<SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Green" />
<HierarchicalDataTemplate DataType="{x:Type scopeSelection:WrapperSimulatedInfoStudy}" ItemsSource="{Binding Path=Childs}">
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding Path=IsSelected}"></CheckBox>
<TextBlock Text="{Binding Path=TvItemName}" Margin="5,0,0,0"></TextBlock>
</StackPanel>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type scopeSelection:WrapperSimulatedInfoSimulation}">
<StackPanel Orientation="Horizontal" ToolTip="{Binding Path=Item.InvalidityReason}">
<StackPanel.Style>
<Style TargetType="{x:Type StackPanel}">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=Item.IsValid}" Value="false">
<Setter Property="Opacity" Value="160"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</StackPanel.Style>
<CheckBox IsChecked="{Binding Path=IsSelected}" IsEnabled="{Binding Path=Item.IsValid}" ToolTip="{Binding Path=Item.InvalidityReason}"></CheckBox>
<CheckBox IsChecked="{Binding Path=IsHilighted}"></CheckBox>
<TextBlock Text="{Binding Path=TvItemName}" Margin="5,0,0,0" ToolTip="{Binding Path=Item.InvalidityReason}">
<TextBlock.Style>
<Style TargetType="{x:Type TextBlock}">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=Item.IsValid}" Value="false">
<Setter Property="Background" Value="LightPink"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.Resources>
</TreeView>
You could define one more property called IsItemSelected and bind it to TreeViewItems IsSelected property (similar to how you have done for IsExpanded).
<Style TargetType="TreeViewItem">
<Setter Property="IsExpanded" Value="{Binding Path=IsExpanded}"/>
<Setter Property="IsSelected" Value="{Binding Path=IsItemSelected}"/>
</Style>
Then you could define a DataTrigger for the IsItemSelected property and set the background color.
<DataTrigger Binding="{Binding Path=IsItemSelected}" Value="true">
<Setter Property="Background" Value="Blue"></Setter>
</DataTrigger>

How to get rid of the red border when a DataGrid cell is invalid?

How do I do this? I want to get rid of that annoying red border that shows on each invalid datagrid cell.
You can just add this line to your DataGrid:
<DataGrid Validation.ErrorTemplate="{x:Null}" />
I had this same issue but in my case I wasn't using IDataError or INotifyDataErrorInfo. I'm using a custom ValidationRule and styles to handle my validation logic and presentation. I was already using the DataGrid RowStyle to display a custom style for the row that has errors so I thought it would be easy to do something similar with the DataGridCell.
Things to note:
You can't just define a style and set the DataGrid.CellStyle. Instead you have to use the ElementStyle and/or the EditingElementStyle.
The style TargetType has to match the DataGridColumn type that the cell is using. So for a DataGridComboBoxColumn the TargetType should be ComboBox
DataGrid Column XAML:
<DataGridComboBoxColumn Header="Column1"
ItemsSource="{Binding Path=Column1Path}"
DisplayMemberPath="Column1DisplayPath"
ElementStyle="{StaticResource DGComboColValidationStyle}"
EditingElementStyle="{StaticResource DGComboColValidationStyle}">
<DataGridComboBoxColumn.SelectedItemBinding>
<Binding Path="Column1Path" UpdateSourceTrigger="LostFocus">
<Binding.ValidationRules>
<Validation:CustomValidationRule ValidationStep="UpdatedValue" ValidatesOnTargetUpdated="True" />
</Binding.ValidationRules>
</Binding>
</DataGridComboBoxColumn.SelectedItemBinding>
</DataGridComboBoxColumn>
Style Definitions
<Style x:Key="DGComboColValidationStyle" TargetType="{x:Type ComboBox}">
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<Grid>
<Border BorderThickness="1"
BorderBrush="{Binding ElementName=adorner1, Path=DataContext[0].ErrorContent.ValidationType, Converter={StaticResource ValidationTypeColorConverter}}"
CornerRadius="3">
</Border>
<AdornedElementPlaceholder Name="adorner1"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="DGTextColValidationStyle" TargetType="{x:Type TextBlock}">
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<Grid>
<Border BorderThickness="1"
BorderBrush="{Binding ElementName=adorner2, Path=DataContext[0].ErrorContent.ValidationType, Converter={StaticResource ValidationTypeColorConverter}}"
CornerRadius="3">
</Border>
<AdornedElementPlaceholder Name="adorner2"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="DGRowValidationStyle" TargetType="{x:Type DataGridRow}">
<Setter Property="ValidationErrorTemplate">
<Setter.Value>
<ControlTemplate x:Name="DGRowValidationTemplate">
<Grid>
<Ellipse Width="12" Height="12" Stroke="Black" StrokeThickness="0.5"
Fill="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGridRow}}, Path=(Validation.Errors)[0].ErrorContent.ValidationType, Converter={StaticResource ValidationTypeColorConverter}}"/>
<TextBlock FontWeight="Bold" Padding="4,0,0,0"
Margin="0" VerticalAlignment="Top" Foreground="White" Text="!"
ToolTip="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGridRow}}, Path=(Validation.Errors)[0].ErrorContent.ValidationMessage}"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="BorderThickness" Value="2"/>
<Setter Property="BorderBrush" Value="{Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors)[0].ErrorContent.ValidationType, Converter={StaticResource ValidationTypeColorConverter}}"/>
</Trigger>
<Trigger Property="Validation.HasError" Value="false">
<Setter Property="BorderThickness" Value="0"/>
<Setter Property="BorderBrush" Value="Transparent" />
</Trigger>
</Style.Triggers>
</Style>
<Style x:Key="DGCellStyle" TargetType="{x:Type DataGridCell}">
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="false">
<Setter Property="BorderThickness" Value="0"/>
<Setter Property="BorderBrush" Value="Transparent" />
<Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGridRow}}, Path=(Validation.Errors)[0].ErrorContent.ValidationMessage}"/>
</Trigger>
</Style.Triggers>
</Style>
Reference:
http://social.msdn.microsoft.com/Forums/vstudio/en-US/6d2d6513-7bca-4359-a12b-46da3c380b0a/wpf-4-datagrid-editingelementstyle-and-validationerrortemplate-adorner-layer?forum=wpf
Set the ValidatesOnDataErrors and ValidatesOnExpcetions to False for your binding of your cell.
In case you want your validations, then you have to override the Validation Template for your control. Please refer to my answer here -
Validation Error Style in WPF, similar to Silverlight
I hated the red border because it was put in the adorner and adorners sit on top of the window, meaning that if your element is partially/fully hidden by another element (like it is in a grid) the full adorner still shows :(
That didn't mean I didn't want some customization though, so I can still highlight my items in pink, or change their foreground and have the DataGridCell correctly clip everything off. You can do this by using a style trigger.
Hope this helps!
<DataGrid.Resources>
<Style TargetType="{x:Type TextBlock}" x:Key="TextBlockErrorStyle">
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<!-- Just the adorned element means NO RED BORDER -->
<AdornedElementPlaceholder Name="controlWithError" />
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="Foreground" Value="Red"/>
<Setter Property="Background" Value="Pink"/>
<Setter Property="ToolTip"
Value="{Binding RelativeSource={RelativeSource Self},
Path=(Validation.Errors)[0].ErrorContent}"/>
</Trigger>
</Style.Triggers>
</Style>
</DataGrid.Resources>
...
<DataGridTemplateColumn Header="Description" MinWidth="150">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=Description, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True, NotifyOnValidationError=True}"
Style="{StaticResource ResourceKey=TextBlockErrorStyle}"
/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
You can check this as well
How to: Implement Validation with the DataGrid Control

WPF - Access the parent Control from inside a Style Setter ControlTemplate

When making controls non-amendable we display them as a TextBox to keep a consistent style. The problem is that a ComboBox can have any type of data so binding the Text property of the ControlTemplate TextBox is not as simple as using SelectedItem.
<Style TargetType="{x:Type ComboBox}">
<Style.Triggers>
<Trigger Property="IsReadOnly" Value="True">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<TextBox Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}, Path=????, Converter={StaticResource ResourceKey=ComboToTextConverter}, UpdateSourceTrigger=PropertyChanged}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
The idea I have is to use a Converter and send the whole ComboBox so it can be handled by the Converter code. Is there anyway to do this?
Any other suggestions are welcome!
you need to use the SelectedValue and SelectedValuePath properties:
<Style TargetType="ComboBox" x:Key="cStyle">
<Style.Triggers>
<Trigger Property="IsReadOnly" Value="True">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ComboBox">
<TextBox Text="{Binding RelativeSource=
{RelativeSource TemplatedParent},
Path=SelectedValue}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
and heres your ComboBox
<ComboBox Name="cbox" ItemsSource="{Binding}"
Style="{StaticResource cStyle}"
SelectedValuePath="SomeText"
DisplayMemberPath="SomeText" />
now when you set the IsReadOnly property to true on the ComboBox, it turns into a TextBox with the selected value as its text.

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