My WPF application has a DataGrid
control in it. I have a default custom style for the DataGridRow
class which works well. However, for this one particular DataGrid
on this one particular screen, I need a different custom style.
The Items in each row have a bool
property that, when set, I want to display that row with a different foreground and background color. However, when the row is selected AND when that property is set, I want a different foreground and background color to show that it's selected AND the property is set to true.
Here's what I've tried:
<Style TargetType="DataGridRow" x:Key="CameraStyle">
<Setter Property="Foreground" Value="{DynamicResource TextForeground}" />
<Setter Property="Background" Value="{DynamicResource DataBackground}" />
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Property="IsSelected" Value="False" />
<Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
</MultiDataTrigger.Conditions>
<Setter Property="Foreground" Value="Red" />
<Setter Property="Background" Value="Yellow" />
</MultiDataTrigger>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Property="IsSelected" Value="True" />
<Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
</MultiDataTrigger.Conditions>
<Setter Property="Background" Value="DarkOrange" />
<Setter Property="BorderBrush" Value="{DynamicResource DataBorder}" />
<Setter Property="Foreground" Value="DarkRed" />
</MultiDataTrigger>
</Style.Triggers>
</Style>
This gives me a "Binding must be non-null" error, which I think is happening because there is no Binding
property on the first condition in the MultiDataTrigger.
What is the correct way to write this in XAML?
EDIT:
After trying nemesv's & Rachel's answer, the code now compiles and runs. However, the colors I've chosen for the IsSelected = true and IsInLiveMode = true case are not showing up. Here's what I have now:
<Style TargetType="DataGridRow" x:Key="CameraStyle">
<Setter Property="Background" Value="{DynamicResource DataBackground}" />
<Setter Property="Foreground" Value="{DynamicResource TextForeground}" />
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Path=IsSelected, RelativeSource={RelativeSource Self}}" Value="False" />
<Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
</MultiDataTrigger.Conditions>
<Setter Property="Background" Value="Yellow" />
<Setter Property="Foreground" Value="Red" />
</MultiDataTrigger>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Path=IsSelected, RelativeSource={RelativeSource Self}}" Value="True" />
<Condition Binding="{Binding Path=IsInLiveMode}" Value="False" />
</MultiDataTrigger.Conditions>
<Setter Property="Background" Value="{DynamicResource DataBackgroundSelected}" />
<Setter Property="BorderBrush" Value="{DynamicResource DataBorder}" />
<Setter Property="Foreground" Value="{DynamicResource DataForegroundSelected}" />
</MultiDataTrigger>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Path=IsSelected, RelativeSource={RelativeSource Self}}" Value="True" />
<Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
</MultiDataTrigger.Conditions>
<Setter Property="Background" Value="DarkOrange" />
<Setter Property="BorderBrush" Value="{DynamicResource DataBorder}" />
<Setter Property="Foreground" Value="DarkRed" />
</MultiDataTrigger>
</Style.Triggers>
</Style>
Any ideas on why the case in question isn't working?
Your assumptution is correct regarding the missing binding.
From MSDN MultiDataTrigger.Conditions:
For a MultiDataTrigger, each condition in the collection must set both the Binding and Value properties.
You can solve this using RelativeSource Self to refer yourself in the binding:
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding RelativeSource={RelativeSource Self},
Path=IsSelected}" Value="True" />
<Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
</MultiDataTrigger.Conditions>