<ControlTemplate x:Key="DefaultErrorTemplate">
<DockPanel LastChildFill="True">
<DKMS:WarningImage Margin="10,0,0,0"
DockPanel.Dock="Right"
Notification="{Binding ElementName=MyAdorner,
Path=AdornedElement.(Validation.Errors)[0].ErrorContent}" />
<AdornedElementPlaceholder Name="MyAdorner" />
</DockPanel>
</ControlTemplate>
And in text box style:
<Setter Property="Validation.ErrorTemplate" Value="{StaticResource DefaultErrorTemplate}" />
The question is how do I force the layout update that is triggered by mouse over? It is also triggered by a MessageBox.
If this is an ErrorTemplate, then you display it by telling the binding system that the binding is invalid. Typically this is done through the IDataErrorInfo interface. But again, this assumes that you're using some sort of binding on the TextBox, typically the Text property.
Here's a blog post about the topic: http://weblogs.asp.net/marianor/archive/2009/04/17/wpf-validation-with-attributes-and-idataerrorinfo-interface-in-mvvm.aspx
It sounds, though, like you are using "event based" programming, and so I don't think you want to use Validation.ErrorTemplate, it sounds like you really want to do some custom adorners. You might want to check out this CodeProject post: http://www.codeproject.com/Articles/54472/Defining-WPF-Adorners-in-XAML on that topic.
Related
I've got a custom ListBox control with a style set up in my Themes/Generic.xaml. I then have a button in the ListBox's ItemTemplate, and it's Click event isn't firing and I've got no idea why. Same goes for the button's Commands (I'm confident the Command issue isn't DataContext related) and interaction triggers. While attempting to debug, I noticed that using the default ListBox instead of my own stopped the problem, but I need to use the custom control.
This is essentially what I've got (fluff removed for brevity). The button:
<controls:CustomListBox>
<ListBox.ItemTemplate>
<DataTemplate>
<Button Click=MyHandler/>
</DataTemplate>
</ListBox.ItemTemplate>
</controls:CustomListBox>
And the custom control's style in Themes/Generic:
<Style TargetType="{x:Type controls:CustomListBox}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type controls:CustomListBox}">
<Border>
<ScrollViewer Focusable="false" Padding="{TemplateBinding Padding}">
<ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</ScrollViewer>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
How can I get this event to fire?
I think this should probably be a usercontrol rather than a custom control.
Are you really going to change the template out of this for something else?
If you use an event handler like that then how are you planning on using the delegate? It's a very inflexible way of working you're headed in.
You mentioned command, which is probably rather more like it.
If you use a button in an item template with a command bound like
<Button Command="{Binding RowCommand}"
Then the datacontext of that Button is the content of the row.
If you bind ItemsSource to a collection Items of ItemVM then it's looking in the ItemVM that is presented to that row.
I would like to add a tooltip over the datapoint of a lineseries that shows both the X and Y values (independent and dependent values), rather than just the dependent value that appears by default. I am aware this is the same question as was written in this ticket - WPF toolkit charting : Customize datapoint label
However, I can't get the answer to work. There is a link to more detail that appears to be outdated.
My line series:
<DVC:Chart.Series>
<!--Have several lineseries that look like this, connected to a styling vm. Can add ToolTip=...-->
<VM:LineSeries x:Name="something"
Title="something"
DependentValuePath="Value"
IndependentValuePath="Key"
ItemsSource="{Binding something}"
DataPointStyle="{StaticResource DataPointBlue}"
>
</VM:LineSeries>
</DVC:Chart.Series>
My datapoints are styled here, but adding a setter property with any tooltip doesn't make a difference:
<UserControl.Resources>
<Style x:Key="DataPointBlue" TargetType="{x:Type DVC:DataPoint}">
<Setter Property="Background" Value="Blue"/>
</Style>
</UserControl.Resources>
I've tried adding this line of code from the above linked ticket in several places in a variety of ways, and I've tried using Binding in various ways, but nothing has hit the mark.
<ToolTipService.ToolTip>
<StackPanel Margin="2,2,2,2">
<ContentControl Content="{TemplateBinding IndependentValue}" />
<ContentControl Content="{TemplateBinding DependentValue}" />
</StackPanel>
</ToolTipService.ToolTip>
This has been a lot of trial and error that hasn't been making progress.
I have a style in the Textboxstyles.xaml as following
<Style x:Key="EmptyItemsControlUsabilityDashboard2017Style" TargetType="ItemsControl">
<Style.Triggers>
<Trigger Property="HasItems" Value="false">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Control">
<StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
<Image Height="12" Width="12" Source="/YoLo;component/Resources/Images/link.png" Margin="0,3,0,0" />
<TextBlock x:Name="EmptyCollectionTextBox" Text="{x:Static UsabilityDashboard2017Loc:DashboardUsability2017Resource.lblNumNotDefined}"
Style="{StaticResource UsabilityDashboard2017TextBoxStyle}"
HorizontalAlignment="Center"
Margin="5,25,0,25"/>
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
and I have used it inside another Xaml file as following
<ItemsControl ItemsSource="{Binding YoLoViewModelsCollection}" Name="YoLoViewModelsItemSource" Style="{StaticResource EmptyItemsControlUsabilityDashboard2017Style}">
Now it shows a text box that the this collection is empty but how can I set command bindings on the text block named "EmptyCollectionTextBox" inside the style that user user click it executes a command?
I have already seen the custom commands but somehow they are not working.
There's actually a lot of stuff wrong with this code. First of all I have no idea what that trigger is supposed to be doing, it looks like the controltemplate will only be set if there are no elements in the list?
Secondly, it looks like you're trying to represent each element in the collection with an image and text, all in an ItemsControl. You don't do that by templating the entire control, you do it by templating the ItemTemplate. And you use a DataTemplate, not a ControlTemplate:
Now going back to your actual question, you want notification whenever the TextBlock is clicked on. There are a multitude of different ways to do this, but for this case you may as well replace that TextBlock with a Button, and then override the Template with a ControlTemplate that represents it as a TextBlock. This gives you the best of both worlds: from the GUI's perspective it's really still a TextBlock, but you still get all the button click notifications and Command handler etc:
<Image />
<Button Command="{Binding ClickedCommand}" Cursor="Hand">
<Button.Template>
<ControlTemplate>
<TextBlock Text="Text Binding Goes Here" />
</ControlTemplate>
</Button.Template>
</Button>
This particular example assumes that the items in your collection have a command handler called "ClickedCommand". In practice your handler might reside in the parent class (e.g. the main window's view model), in which case you'd need to give your main window a x:Name (e.g. "_this") and bind to that instead, passing the item in as the CommandParameter so it knows which one was clicked:
<Button Command="{Binding ElementName=_this, Path=DataContext.ClickedCommand}" CommandParameter="{Binding}" Cursor="Hand">
And then your main view model has a handler that looks something like this:
public ICommand ClickedCommand { get { return new RelayCommand<YourCollectionItemType>(OnClicked); } }
private void OnClicked(YourCollectionItemType item)
{
}
I am modeling an attached command pattern after the AttachedCommandBehavior library here. My button looks like this:
<Button>
<Button.Style>
<Style TargetType="{x:Type Button}">
<Setter Property="vms:Attached.Behaviors">
<Setter.Value>
<vms:Behaviors>
<vms:Behavior Event="Click"
Command="{Binding ClickCommand}" />
</vms:Behaviors>
</Setter.Value>
</Setter>
</Style>
</Button.Style>
</Button>
Everything works great, but when the setter on the Behavior is executed, the Command is null.
Behavior is a Freezable, and Behaviors is a FreezableCollection<Behavior>. It just doesn't seem to be inheriting the DataContext from the Button.
On the other hand, this works correctly:
<Button>
<vms:Attached.Behaviors>
<vms:Behavior Event="Click" Command="{Binding ClickCommand}" />
</vms:Attached.Behaviors>
</Button>
Unfortunately I can't do it this way, because I need to target generated ListViewItems using ItemContainerStyle.
Is there some way to get the DataContext in the Style?
The Attached Command Behavior library is the germ of the idea that became Blend Behaviors. The Blend Behaviors are much more powerful and standardized and so I recommend you switch to using them. But whether you are using Attached Command Behavior or Blend Behaviors, the problem is essential the same: they don't work as expected when trying to set them using a style. I've solved this problem for Blend Behaviors with full support for binding in this StackOverflow answer:
How to add a Blend Behavior in a Style Setter
Without testing it, I guess you have to move the ACB behavior to a resource marked with x:Shared="False" in order to get the binding to work.
I had the same problem, and using RelativeSource did the trick. I'll show you my before and after code...
Before: (This DIDN'T work)
<DataTemplate x:Key="MenuNodeWithChildrenTemplate">
<StackPanel Orientation="Horizontal"
behaviors:EventCommand.CommandToRun="{Binding OpenMenuItem}"
behaviors:EventCommand.EventName="MouseLeftButtonUp">
<Label Content="{Binding Title}"/>
<Label Content="{Binding Description}"/>
</StackPanel>
</DataTemplate>
After: (This DOES work)
<DataTemplate x:Key="MenuNodeWithChildrenTemplate">
<StackPanel Orientation="Horizontal"
behaviors:EventCommand.CommandToRun="{Binding Path=DataContext.OpenMenuItem, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ItemsControl}}}"
behaviors:EventCommand.EventName="MouseLeftButtonUp">
<Label Content="{Binding Title}"/>
<Label Content="{Binding Description}"/>
</StackPanel>
</DataTemplate>
You'll obviously have to tweak the parameters of the Relative Source to your specific situation. It seems that, for whatever reason, attached properties don't inherit the data context, so you have to tell if how to.
How do I set the background colour of items in a list box dynamically? i.e. there is some property on my business object that I'm binding too, so based on some business rules I want the background colour to be different?
<ListBox Background="Red">
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="Background" Value="Red"/>
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal"
Margin="5">
<TextBlock VerticalAlignment="Bottom"
FontFamily="Comic Sans MS"
FontSize="12"
Width="70"
Text="{Binding Name}" />
<TextBlock VerticalAlignment="Bottom"
FontFamily="Comic Sans MS"
FontSize="12"
Width="70"
Text="{Binding Age}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
EDIT: It says here
In Silverlight, you must add x:Key
attributes to your custom styles and
reference them as static resources.
Silverlight does not support implicit
styles applied using the TargetType
attribute value.
Does this impact my approach?
Ok - if you need custom logic to determine the background then I would look into building a simple IValueConverter class. You just need to implement the IValueConverter interface and, in its Convert method, change the supplied value into a Brush.
Here's a quick post from Sahil Malik that describes IValueConverters - it might help:
http://blah.winsmarts.com/2007-3-WPF__DataBinding_to_Calculated_Values--The_IValueConverter_interface.aspx
To bind your background to more than one property, you can use IMultiValueConverter. It's just like IValueConverter except that it works with MultiBinding to pass more than one value into a class and get back a single value.
Here's a post I found with a run-through on IMultiValueConverter and MultiBinding:
http://blog.paranoidferret.com/index.php/2008/07/21/wpf-tutorial-using-multibindings/
Edit: If IMultiValueConverter isn't available (it looks like Silverlight only has IValueConverter) then you can always pass your entire bound object (eg your Person object) to an IValueConverter and use various properties from that to return your Brush.
#Matt Thanks for the reply. I'll look into triggers.
My only problem is that, the logic for determining whether a row should be coloured is slightly more involved so I cant just checking a property, so I actually need to run some logic to determine the colour. Any ideas?
I guess I could make a UI object with all the relevant fields I need, but I kinda didnt want to take the approach.
You could try binding something in your controltemplate (ie a border or something) to the TemplateBackground. Then set the background on your listbox to determine the colour it will be.
<Border Margin="-2,-2,-2,0" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0" CornerRadius="11,11,0,0">