I'm puzzled by a peculiar phenomenon in RibbonButton's behavior.
Everything works fine when I set the LargeImageSource and the Label statically in XAML:
<ribbon:RibbonButton x:Name="ButtonArchive"
LargeImageSource="..\Assets\archive_insert.png"
Label="{Binding Path=ItemArchiveButton,
Source={StaticResource Strings}}"/>
But when I try to modify these properties via DataTriggers - nothing seems to be happening.
The triggers do work; I can see the other properties - like Command or IsEnabled - set OK in the same trigger. It's just these too...
Here's the XAML:
<ribbon:RibbonButton x:Name="ButtonArchive"
LargeImageSource="..\Assets\archive_insert.png"
Label="{Binding Path=ItemArchiveButton, Source={StaticResource Strings}}">
<ribbon:RibbonButton.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding ="{Binding ElementName=ItemsList, Path=SelectedItem.IsArchived}" Value="false">
<Setter Property="ribbon:RibbonButton.Command" Value="{Binding ArchiveItemCommand}" />
<Setter Property="ribbon:RibbonButton.LargeImageSource" Value="..\Assets\archive_insert.png" />
<Setter Property="ribbon:RibbonButton.Label" Value="{Binding Path=ItemArchiveButton, Source={StaticResource Strings}}" />
</DataTrigger>
<DataTrigger Binding ="{Binding ElementName=ItemsList, Path=SelectedItem.IsArchived}" Value="true">
<Setter Property="ribbon:RibbonButton.Command" Value="{Binding RestoreItemCommand}" />
<Setter Property="ribbon:RibbonButton.LargeImageSource" Value="..\Assets\archive_extract.png" />
<Setter Property="ribbon:RibbonButton.Label" Value="{Binding Path=ItemRestoreButton, Source={StaticResource Strings}}" />
</DataTrigger>
</Style.Triggers>
</Style>
</ribbon:RibbonButton.Style>
</ribbon:RibbonButton>
Setting the Command works fine in the both conditions, but not the other 2 properties...
Any advice will be welcome.
I asked the same question at the MSDN forum, and the answer I've got really solved this.
The problem is your setting properties for LargeImageSource and Label in the button itself. When you do this it takes precidence over your style triggers. I suggest using setters in the style to set your defaults, and remove the property settings it the button.
Related
I am making a window that shows the user multiple options, with each a radiobutton and a textbox.
When opening this window, the focus should be on the textbox corresponding to the radiobutton that is checked when opening the window (this is all preset, no need to worry about this).
It is important that it gets fixed either in xaml or in the code-behind.
I have used a DataTrigger to change the FocusedElement to the right textbox, however it gets overwritten after it is set.
The relevant code is in the DataTrigger below. The color gets changed correctly, however the FocusElement does not.
I have tried all the options that I have found on stackoverflow and google. The issue does not lie in the DataTrigger or the setting of the FocusedElement. I think it lies in the fact that it gets overridden at the end. I have used Snoop to see the changes in the Keyboard.FocusedElement and it does not show any change.
<DataTemplate x:Uid="DataTemplate_1" >
<RadioButton x:Uid="RadioButton_1" GroupName="Options" IsChecked="{Binding IsSelected}" Margin="4,0,0,0" Name="RadioBtn">
<StackPanel x:Uid="StackPanel_1" Orientation="Horizontal" >
<Label x:Uid="Label_1" Visibility="{Binding IsUserInput, Converter={cs:OppositeVisibilityConverter}}" Content="{Binding Description, Mode=OneWay}" />
<Label x:Uid="Label_2" Visibility="{Binding IsUserInput, Converter={cs:VisibilityConverter}}" Content="Anders, nl: " />
<TextBox x:Uid="MemAnders" Visibility="{Binding IsUserInput, Converter={cs:VisibilityConverter}}" Text="{Binding AlternativeText}"
Name="MemAnders" MinWidth="400" IsTabStop="False"
>
<TextBox.Style>
<Style TargetType="{x:Type TextBox}">
<Style.Triggers>
<DataTrigger Binding="{Binding IsSelected}" Value="True">
<Setter Property="FocusManager.FocusedElement" Value="{Binding ElementName=MemAnders}"/>
<Setter Property="Background" Value="LightGoldenrodYellow" />
</DataTrigger>
<DataTrigger Binding="{Binding IsSelected}" Value="False">
<Setter Property="FocusManager.FocusedElement" Value="{Binding ElementName=RadioBtn}"/>
<Setter Property="Background" Value="LightBlue" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>
</StackPanel >
</RadioButton >
</DataTemplate >
The textbox corresponding to the checked radiobutton should be focused. Instead another (parent?) object is focused.
Anyone know a workaround for this?
The work-around turned out to be setting focus to the textbox in the Window_Loaded function.
I used an algorithm provided by Find a WPF element inside DataTemplate in the code-behind to find the correct textbox element. Then I did TextBox.Focus(); and that fixed it.
I am trying to switch the content of a contentpresenter based on a datatrigger.I want to display a usercontrol in the contentpresenter.content, if i have a value set or else i need to display an error message.But the binding on my datatrigger fails stating that the property is not found.I cant get the datacontext to inherit for the datatrigger checking.I can make it work by using the commented out code.But i am confused why it doesn't work the normal way.
<ContentPresenter.Style>
<Style TargetType="{x:Type ContentPresenter}">
<Setter Property="Content" Value="{Binding UC}"/>
<Style.Triggers>
<!--<DataTrigger Binding="{Binding DataContext.HasValue,RelativeSource={RelativeSource AncestorType={x:Type ContentPresenter}}}" Value="false">
<Setter Property="Content" Value="No preview"/>
</DataTrigger>-->
<DataTrigger Binding="{Binding HasValue}" Value="false">
<Setter Property="Content" Value="No value"/>
</DataTrigger>
</Style.Triggers>
</Style>
</ContentPresenter.Style>
</ContentPresenter>
If you want to use triggers to display UserControl, you should use ContentControl not ContentPresenter.
I prefer to use ContentPresenter for CustomControls and When I am using the UserControl for views of Custom Data Types in my system and Allow to give dynamic behavior.
Example: To switch templates for ContentPresenter you need to set ContentTemplateSelector like this
<ContentPresenter Content="{Binding MyContent}"
ContentTemplate="{Binding MyContentTemplate}"
ContentTemplateSelector="{Binding MyContentTemplateSelector}"/>
MyContent, MyContentTemplate & MyContentTemplateSelector are Dependency Properties and can be binded wherever you are using its instance.
READ :
Usage of ContentPresenter
What is the difference between ContentControl and ContentPresenter
The binding mentioned in the question won't work as
ContentPresenter’s DataContext is automatically set to the value of
its Content property, while ContentControl’s DataContext is not.
Bindings are resolved relatively to the value of the DataContext property. If you declare a binding on the ContentPresenter, the moment its content is set, the binding would be re-evaluated.
ContentControl.Content Property can be changed on any trigger based on your requirement. If you want to use it to change on PropertyChanged Event of a property of ViewModel, DataTrigger can be used by binding it with a DataTemplate with UserControl instance in it or using static resource of that UserControl.
<ContentControl>
<ContentControl.Style>
<Style TargetType="{x:Type ContentControl}">
<Setter Value="{StaticResource UnSelectedDataTemplate}" Property="ContentTemplate" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsSelected}" Value="True">
<Setter Value="{StaticResource SelectedDataTemplate}" Property="ContentTemplate" />
</DataTrigger>
</Style.Triggers>
</Style>
</ContentContro.Style>
</ContentControl>
READ How to use triggers for content template, more details here
Difference in DataTemplate and StaticResource scope is DataTemplate creates a new instance of the template every time its applied.
Whereas, StaticResource is using the same instance of UserControl again (Static Instance).
You can also use EventTriggers to change content base don Control Events like MouseOver etc.
Alternate approach
Very similar to the above with slight difference. Defining as a data template in resources. Triggering for the content change is essentially identical.
...in <x.Resources /> tag:
<DataTemplate x:Key="DesignerTemplate" DataType="{x:Type vm:SolutionViewModel}">
<vw:SolutionDesignerView />
</DataTemplate>
<DataTemplate DataType="{x:Type vm:SolutionViewModel}">
<ContentControl Content="{Binding }">
<ContentControl.Style>
<Style TargetType="{x:Type ContentControl}">
<Style.Triggers>
<DataTrigger Binding="{Binding IsLoaded}" Value="True">
<Setter Property="ContentTemplate" Value="{StaticResource DesignerTemplate}" />
</DataTrigger>
</Style.Triggers>
</Style>
</ContentControl.Style>
</ContentControl>
</DataTemplate>
...then:
<ContentControl Content="{Binding Solution}" />
I usually use trigger Like this...
<UserControl>
<UserControl.Resources>
<DataTemplate x:Key="normalTemplate" >
<!-Fav UserControl->
</DataTemplate >
<DataTemplate x:Key="overWriteTempalte">
<!-Fav UserControl-> </DataTemplate>
</UserControl.Resources>
<ContentPresenter x:Name="ContentField"
Content="{Binding}"
ContentTemplate="{StaticResource ResourceKey=normalTemplate}" />
<UserControl.Triggers>
<DataTrigger Binding="{Binding Path=MyProperty}" Value="True">
<Setter TargetName="ContentField" Property="ContentTemplate" Value="{StaticResource ResourceKey=overWriteTempalte}" />
</DataTrigger>
</UserControl.Triggers>
</UserControl>
If Bindings are a problem Use Snoop to Detect binding errors
I'm looking to a way to bind a Button Text or IsEnabled property for example to the IsChecked property in an ItemsControl
Here is my simplified source code :
<StackPanel>
<ItemsControl ItemsSource="{Binding Tasks}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Margin="10,0,10,0" Text="{Binding Name}"/>
<CheckBox IsChecked="{Binding InProgress}"/>
<CheckBox IsChecked="{Binding Done}"/>
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<Button/>
</StackPanel>
I would like (for example) if all the "Done" CheckBoxes are Checked, to set Button Text to some value or to enable it. I thought doing this with Data Binding in Xaml using DataTriggers but I don't know how to do it.
Ca anyone give me a full xaml solution ?
New Answer
Sorry, I misunderstood the question. I would expose another property from your DataContext that simply returns true/false if all the items in the collection are checked or not, and base your Button's Text/IsEnabled off that property using a DataTrigger
<Style TargetType="{x:Type Button}">
<Setter Property="IsEnabled" Value="False" />
<Style.Triggers>
<DataTrigger Binding="{Binding IsAllChecked}" Value="True">
<Setter Property="IsEnabled" Value="True" />
</DataTrigger>
</Style.Triggers>
</Style>
Old Answer
DataTriggers simply take a binding, and check if the result is equal to some value.
<Style TargetType="{x:Type TextBox}">
<Setter Property="IsEnabled" Value="False" />
<Style.Triggers>
<DataTrigger Binding="{Binding Done}" Value="True">
<Setter Property="IsEnabled" Value="True" />
</DataTrigger>
</Style.Triggers>
</Style>
If you need to test more than one condition, you need a MultiDataTrigger
<Style TargetType="{x:Type TextBox}">
<Setter Property="IsEnabled" Value="False" />
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Path=InProgress}" Value="True" />
<Condition Binding="{Binding Path=Done}" Value="True" />
</MultiDataTrigger.Conditions>
<Setter Property="IsEnabled" Value="True" />
</MultiDataTrigger>
</Style.Triggers>
</Style>
Note that the default value of setter is part of the style. This is important because if you set the default value on the <TextBox> then it has a higher priority than triggered values, so triggered values are unable to change the current value.
You can change this line...
<Button/>
To this
<Button Content={Binding ButtonContent}/>
And set the 'ButtonContent' property in your ViewModel whenever your 'Done' check box gets checked.
Usually, the best way to do that is to synthesize the state you want to apply to your button into a property of your ViewModel.
The WPFy way in that case is for your ViewModel to expose a command that implements the action of your button.
The command in turns can react to changes in your data to signal if it is available or not, and thus will automaticaally disable/enable your button. An added bonus is that you can easily implement a menu for example, that will be properly enabled/disabled at no cost once you have your command.
It's been a long time since I had any chance to touch WPF, so I do not have any really useful links at hand, but if I were you I would learn about commands in WPF, they are a very important part of the MVVM architecture.
I have the next code in my view:
<Style x:Key="documentFileNameStyle">
<Setter Property="TextBlock.Foreground" Value="Gray"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=Untitled}" Value="True">
<Setter Property="TextBlock.FontStyle" Value="Italic"/>
<Setter Property="TextBlock.Text" Value="no file name"/>
</DataTrigger>
</Style.Triggers>
</Style>
<DataTemplate x:Key="documentTemplate">
<TextBlock Text="{Binding Path=FileName}" Style="{StaticResource documentFileNameStyle}"/>
</DataTemplate>
But setting TextBlock.Text to a string didn't work. TextBlock.FontStyle changes to Italic, so whole trigger works properly. What is wrong?
Local assignment of Properties has a higher precedence than setting the values in triggers.
Also you are using Binding (Path=FileName) to set the Text-Property of the TextBlock. So changing the Text in Triggers doesn´t effect the Property.
As you are using Binding. I would change the Property "FileName" to return "no file name" if the Property "Untitled" is "true".
In a WPF application, I have correctly bound a DataTemplate to an XML node that looks like:
<answer answer="Tree", correct="false" score="10" />
In my application, I have a TextBlock with the answer in it. At first, I want it invisible, but when the correct attribute in the XML file changes to "true", it must become visible.
My DataTemplate is hooked up correctly, because everything else works. For example, if I change the answer attribute in the XML file (just for testing), it changes in my WPF view. But I'm having troubles with the visibility. This is my XAML:
<TextBlock Text="{Binding XPath=#answer}" Visibility="Hidden">
<TextBlock.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding="{Binding XPath=#correct}" Value="true">
<Setter Property="TextBlock.Visibility" Value="Visible" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
I'm guessing the Databinding in the DataTrigger isn't working correctly. Anyone have a clue?
I have run into the same problem with databound ToggleButtons. Try removing the Visibility="False" and replacing it with another DataTrigger that handles the incorrect case.
I think the issue is that the Visibility property is hard-coded. Try setting the Visibility in the style:
<TextBlock Text="{Binding XPath=#answer}">
<TextBlock.Style>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="Visibility" Value="Hidden"/>
<Style.Triggers>
<DataTrigger Binding="{Binding XPath=#correct}" Value="true">
<Setter Property="TextBlock.Visibility" Value="Visible" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
Sure, it works if you give a specific else case instead of just false. As in my case, it was {x:Null} and value. So when its value to bind is present, it will be true and TextBlock.Visibilty will be set using setters value and when binding path does not have any value inside it, i.e. null in my case, its simply {x:Null} :)