I have a ListBox of custom items ("EditableTextBlock", a normal TextBlock that, on click, becomes a TextBox and then returns a TextBlock after the edits.)
I want to send an event, or to launch a callback to the parent, inform someway that there have been a successful edit;
In the EditableTextBlock I can have a method like
if (e.Key == Key.Enter)
{
this.IsInEditMode = false;
AcceptRenaming(sender, e);
}
and I could use that AcceptRenaming() to send the information somehow, but
I found that, being the item an DataTemplate, I can't use directly an EventHandler (calling from the parent something like
EditTextBlock.RenameEvent += new EventHandler(OnRenameAccepted);)
I tried to create a RoutedEvent following the tips on How do you add an Event Trigger to a data template for a business object?, but I couldn't understand how to register to the EventRegistry to my custom event that I'd create.
What I'm missing here? Or is my approach completely wrong, and there is something else I could/should do?
Thanks in advance
ListBox using the EditableTextBlock:
<ListBox x:Name="lbConfigurationList"
DataContext="{Binding DataContext, RelativeSource={RelativeSource AncestorType={x:Type Window}}}"
ItemsSource="{Binding ConfListVM.ObservableConfList}"
<ListBox.ItemTemplate>
<DataTemplate>
<local:EditableTextBlock Text="{Binding ConfName}" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
EditableTextBlock xaml:
<UserControl.Resources>
<DataTemplate x:Key="EditModeTemplate">
<TextBox KeyDown="TextBox_KeyDown" Loaded="TextBox_Loaded" LostFocus="TextBox_LostFocus"
Text="{Binding ElementName=EditableText, Path=Text, UpdateSourceTrigger=PropertyChanged}"/>
</DataTemplate>
<DataTemplate x:Key="DisplayModeTemplate">
<TextBlock Text="{Binding ElementName=EditableText, Path=Text}" >
<TextBlock.ContextMenu>
<ContextMenu>
<MenuItem Header="Rename" Click="RenameContext_Click"/>
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</DataTemplate>
<Style TargetType="{x:Type local:EditableTextBlock}">
<Style.Triggers>
<Trigger Property="IsInEditMode" Value="True">
<Setter Property="ContentTemplate" Value="{StaticResource EditModeTemplate}" />
</Trigger>
<Trigger Property="IsInEditMode" Value="False">
<Setter Property="ContentTemplate" Value="{StaticResource DisplayModeTemplate}" />
</Trigger>
</Style.Triggers>
</Style>
</UserControl.Resources>
Related
I'm learning WPF and developing a dynamic Menu which is driven by data binding of it's ItemsSource to an ObservableCollection. To do this I have a simple MenuItemViewModel and a HierarchicalDataTemplate for automatic binding of MenuItems to it.
The problem I have is that Command property doesn't work for top level menu items. Despite it is set, a MenuItem doesn't react on mouse click and doesn't get disabled if Command cannot be executed. Simply it's like it's not getting bound.
For lower level menu items though, it works as intended. I think this should be a problem of my HierarchicalDataTemplate but I can't find it, because as I see there's no code in template which might affect command binding of only top-level MenuItems.
MenuItemViewModel implements INotifyPropertyChanged and contains following public properties:
string Text
Uri ImageSource
ICommand Command
ObservableCollection<MenuItemViewModel> Children
HierarchicalDataTemplate for MenuItem in my Window.Resources is as follows:
<HierarchicalDataTemplate DataType="{x:Type common:MenuItemViewModel}"
ItemsSource="{Binding Path=Children}">
<HierarchicalDataTemplate.ItemContainerStyle>
<Style TargetType="MenuItem">
<Setter Property="Command"
Value="{Binding Command}" />
</Style>
</HierarchicalDataTemplate.ItemContainerStyle>
<StackPanel Orientation="Horizontal">
<Image Source="{Binding ImageSource}" />
<TextBlock Text="{Binding Text}" VerticalAlignment="Center"/>
</StackPanel>
</HierarchicalDataTemplate>
Can you please point me on my mistake?
EDIT: Top-level MenuItem doesn't contain any children (i.e. Children collection of associated ViewModel is empty).
Thanks to #sTrenat comment I've come to solution below.
<Menu.Resources>
<!-- cancel sharing of image so Icon will work properly -->
<Image x:Key="MenuIcon" Source="{Binding ImageSource}" x:Shared="False"/>
</Menu.Resources>
<Menu.ItemContainerStyle>
<Style TargetType="{x:Type MenuItem}"
BasedOn="{StaticResource {x:Type MenuItem}}">
<Setter Property="Header" Value="{Binding Text}" />
<Setter Property="Icon" Value="{StaticResource MenuIcon}"/>
<Setter Property="Command" Value="{Binding Command}"/>
<Setter Property="ItemsSource" Value="{Binding Children}" />
<!-- centering MenuItem's Header -->
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" Content="{Binding}" />
</DataTemplate>
</Setter.Value>
</Setter>
<!-- setting Icon to null when ImageSource isn't specified -->
<Style.Triggers>
<DataTrigger Binding="{Binding ImageSource}"
Value="{x:Null}">
<Setter Property="Icon" Value="{x:Null}"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Menu.ItemContainerStyle>
I have a chunk of xaml that duplicates the same pattern six times and would like to reduce that footprint by eliminating the duplication. I'm running into one snag that I need help with.
Background: I have a class that instantiates another class six times (phases of a project as you will).
public ECN(string ecnNumber) {
_ECNNumber = ecnNumber;
//instantiate each phase to be populated or not
_PurchaseParts = new ECNPhase();
_PieceParts = new ECNPhase();
_Weldments = new ECNPhase();
_BOMCfg = new ECNPhase();
_Cleanup = new ECNPhase();
_PRAF = new ECNPhase();
}
Inside each phase is a collection of Changes (another class) referenced in the ECNPhase Class. Each phase has data that is unique to each phase that is shown in a unique view, this is where my snag is which I will show later.
Example of the duplicate xaml Code with the main difference being the different view inside each expander:
<StackPanel Margin="0">
<!--Section for Purchase parts-->
<StackPanel Orientation="Horizontal" >
<CheckBox Margin="0,5,5,5" IsChecked="{Binding Path=MyWorkspace.CurrentSelectedItem.PurchaseParts.HasPhase,Mode=TwoWay}"/>
<StackPanel Orientation="Horizontal">
<StackPanel.Style>
<Style TargetType="{x:Type StackPanel}">
<Setter Property="IsEnabled" Value="False"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=MyWorkspace.CurrentSelectedItem.PurchaseParts.HasPhase}" Value="True">
<Setter Property="IsEnabled" Value="True"/>
</DataTrigger>
</Style.Triggers>
</Style>
</StackPanel.Style>
<Expander Header="Purchase Parts" Margin="0,0,10,0" Width="110">
<view:PurchasePartsView/>
</Expander>
<CheckBox Content="Submit" Margin="10,5,0,5"/> <!--add a command to handle the submit checkbox event-->
<Label Content="Status:" Margin="10,0,0,0" HorizontalContentAlignment="Right" Width="60"/>
<Label Content="{Binding Path=MyWorkspace.CurrentSelectedItem.PurchaseParts.Status}"/>
</StackPanel>
</StackPanel>
<!--Section for Piece Parts-->
<StackPanel Orientation="Horizontal">
<CheckBox Margin="0,5,5,5" IsChecked="{Binding Path=MyWorkspace.CurrentSelectedItem.PieceParts.HasPhase,Mode=TwoWay}"/>
<StackPanel Orientation="Horizontal">
<StackPanel.Style>
<Style TargetType="{x:Type StackPanel}">
<Setter Property="IsEnabled" Value="False"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=MyWorkspace.CurrentSelectedItem.PieceParts.HasPhase}" Value="True">
<Setter Property="IsEnabled" Value="True"/>
</DataTrigger>
</Style.Triggers>
</Style>
</StackPanel.Style>
<Expander Header="Piece Parts" Margin="0,0,10,0" Width="110">
<view:PiecePartsView/>
</Expander>
<CheckBox Content="Submit" Margin="10,5,0,5"/> <!--add a command to handle the submit checkbox event-->
<Label Content="Status:" Margin="10,0,0,0" HorizontalContentAlignment="Right" Width="60"/>
<Label Content="{Binding Path=MyWorkspace.CurrentSelectedItem.PieceParts.Status}"/>
</StackPanel>
</StackPanel>
<!--duplicated four more times-->
</StackPanel>
What I'd like to do is:
<StackPanel>
<view:PhaseView DataContext="{Binding Path=MyWorkspace.CurrentSelectedItem.PurchaseParts}"/>
<view:PhaseView DataContext="{Binding Path=MyWorkspace.CurrentSelectedItem.PieceParts}"/>
<!--four more phases-->
</StackPanel>
Where the PhaseView will be the template that handles the duplication and this is where I'm hitting a snag. Each phase needs a unique view (userControl) selected based off of the datacontext of the PhaseView.
<StackPanel Orientation="Horizontal" >
<CheckBox Margin="0,5,5,5" IsChecked="{Binding Path=HasPhase,Mode=TwoWay}"/>
<StackPanel Orientation="Horizontal">
<StackPanel.Style>
<Style TargetType="{x:Type StackPanel}">
<Setter Property="IsEnabled" Value="False"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=HasPhase}" Value="True">
<Setter Property="IsEnabled" Value="True"/>
</DataTrigger>
</Style.Triggers>
</Style>
</StackPanel.Style>
<Expander Header="DisplayName" Margin="0,0,10,0" Width="110">
<!--add somthing here to select the correct view based on the datacontext-->
<!--<local:PurchasePartsView/> This user control adds a datagrid that is unique to each phase-->
</Expander>
<CheckBox Content="Submit" Margin="10,5,0,5"/> <!--add a command to handle the submit checkbox event-->
<Label Content="Status:" Margin="10,0,0,0" HorizontalContentAlignment="Right" Width="60"/>
<Label Content="{Binding Path=Status}"/>
</StackPanel>
</StackPanel>
I was thinking of using a datatrigger somehow lik shown below, but I haven't had any luck figuring it out. I know there's got to be a way to do this, and it's probably something simple and dumb. Any help would be much appreciated.
<DataTrigger Binding="{Binding Path=DisplayName}" Value="Purchase Parts">
<Setter Property="DataContext" Value="{Binding }"/> <!--Don't know how to bind the DataContext-->
</DataTrigger>
Thanks,
Ok, thanks to Bradley I looked into the DataTemplateSelector and this is what I came up with.
In my UserControl resources I set up several DataTemplates and a reference to the TemplateSelector class that overides the DataTemplateSelector class.
XAML Resources:
<UserControl.Resources>
<local:TemplateSelector x:Key="myTemplateSelector"/>
<DataTemplate x:Key="PurchasePartsTemplate">
<view:PurchasePartsView/>
</DataTemplate>
<DataTemplate x:Key="PiecePartsTemplate">
<view:PiecePartsView/>
</DataTemplate>
<!--Four more templates-->
</UserControl.Resources>
Code Behind for DataTemplateSelector override. Note: I couldn't figure out a way to bind to the ECNPhase class so I bound to the DisplayName property in my class to pull out the correct instance being represented.
class TemplateSelector : DataTemplateSelector {
public override DataTemplate SelectTemplate(object item, DependencyObject container) {
FrameworkElement element = container as FrameworkElement;
if(element != null && item != null && item is string) {
string phase = (string)item;
if(phase == "Purchase Parts") {
return element.FindResource("PurchasePartsTemplate") as DataTemplate;
}else if(phase == "Piece Parts") {
return element.FindResource("PiecePartsTemplate") as DataTemplate;
}
}
return null;
}
}
I'm calling this class in my UserContol like this:
<Expander Header="{Binding Path=DisplayName}" Margin="0,0,10,0" Content="{Binding Path=DisplayName}"
ContentTemplateSelector="{StaticResource myTemplateSelector}"/>
There isn't an items control associated with the expander so I used the content control. I pass the DisplayName into the control property and the contentTemplateSelector uses the myTemplateSelector resource which goes into the codebehind and selects the appropriate datatemplate to use based on the DisplayName.
Now I can call my reusable template like so:
<StackPanel Margin="0">
<view:ChangePhaseView DataContext="{Binding Path=MyWorkspace.CurrentSelectedItem.PurchaseParts}"/>
<view:ChangePhaseView DataContext="{Binding Path=MyWorkspace.CurrentSelectedItem.PieceParts}"/>
</StackPanel>
#Bradley, thank you for pointing me in the right direction.
I want to set two color background to a custom tree view (wpf). You can set this propriety in a DataGrid. I could not figure out a way to do it for a tree view.
I also want to set the selection of a element to be as big as the cell.
<TreeView Grid.Row="2" Name="TreeView" DataContext="{Binding Path=TreeModel}" ItemsSource="{Binding TreeItems}" SelectedItemChanged="TreeView_OnSelectedItemChanged">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type local:NodeViewModel}" ItemsSource="{Binding Children}">
<StackPanel Orientation="Horizontal">
<Label Content="{Binding NameNode}"/>
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.Resources>
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="FontWeight" Value="Normal" />
<Setter Property="ContextMenu">
<Setter.Value>
<ContextMenu>
<MenuItem Header="Add" Command="{Binding AddMachinePart_Command}"/>
<MenuItem Header="Remove" Command="{Binding RemoveMachinePart_Command}" IsEnabled="{Binding IsModule}"/>
<MenuItem Header="Edit" Command="{Binding EditMachinePart_Command}" IsEnabled="{Binding IsModule}"/>
<Separator></Separator>
<MenuItem Header="Copy path" Command="{Binding CopyPath_Command}" IsEnabled="{Binding IsModule}"></MenuItem>
</ContextMenu>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="FontWeight" Value="Bold" />
</Trigger>
</Style.Triggers>
</Style>
</TreeView.ItemContainerStyle>
</TreeView>
Edit:
When using the solution from
https://msdn.microsoft.com/en-us/library/system.windows.controls.itemscontrol.alternationindex(v=vs.110).aspx suggested #jschroedl
It would be ideal to be as large as the tree view grid like shown in picture below:
You will probably want to use ItemsControl.AlternationIndex in a Style to control how many colors to cycle (2 in your case).
MSDN Docs for ItemsControl.AlternationIndex has an example with ListBox which you can probably adapt to TreeView as well.
Some time ago i asked here how to bind the expanded event to the viewmodel and came to a solution using AttachedCommandBehavior:
<TreeView Name="tv" ItemsSource="{Binding TreeViewElements}">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Children, Mode=OneTime}">
<StackPanel Orientation="Horizontal">
<Label Content="{Binding Title, Mode=OneTime}" />
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="local:CommandBehavior.Event" Value="Expanded"></Setter>
<Setter Property="local:CommandBehavior.Command" Value="{Binding DataContext.ExpandCommand, ElementName=tv}"></Setter>
<Setter Property="local:CommandBehavior.CommandParameter" Value="{Binding}"></Setter>
</Style>
</TreeView.ItemContainerStyle>
</TreeView>
Now it is necessary to bind the collapsed event, too.
Adding this to the style section like this does not work, only the collapsed event is binded:
<Setter Property="local:CommandBehavior.Event" Value="Expanded"></Setter>
<Setter Property="local:CommandBehavior.Command" Value="{Binding DataContext.ExpandCommand, ElementName=tv}"></Setter>
<Setter Property="local:CommandBehavior.CommandParameter" Value="{Binding}"></Setter>
<Setter Property="local:CommandBehavior.Event" Value="Collapsed"></Setter>
<Setter Property="local:CommandBehavior.Command" Value="{Binding DataContext.CollapseCommand, ElementName=tv}"></Setter>
<Setter Property="local:CommandBehavior.CommandParameter" Value="{Binding}"></Setter>
Then i found an example on the AttachedCommandBehavior homepage to use a collection of behaviors:
<local:CommandBehaviorCollection.Behaviors>
<local:BehaviorBinding Event="MouseLeftButtonDown" Action="{Binding DoSomething}" CommandParameter="An Action on MouseLeftButtonDown"/>
<local:BehaviorBinding Event="MouseRightButtonDown" Command="{Binding SomeCommand}" CommandParameter="A Command on MouseRightButtonDown"/>
</local:CommandBehaviorCollection.Behaviors>
The problem is that adding such a collection in the style section does not work, visual studio gives the error that the behavior property can not be attached to style.
Has anybody an idea how i can bind both events to the viewmodel?
Do it like this:
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="local:CommandBehaviorCollection.Behaviors">
<Setter.Value>
<local:BehaviorBinding Event="MouseLeftButtonDown" Action="{Binding DoSomething}" CommandParameter="An Action on MouseLeftButtonDown"/>
<local:BehaviorBinding Event="MouseRightButtonDown" Command="{Binding SomeCommand}" CommandParameter="A Command on MouseRightButtonDown"/>
</Setter.Value>
</Setter>
</Style>
My problem is with the following code, with binding the IsAvailable property of the MyListBoxItem class. My current solution:
<ListBox ItemTemplate="{StaticResource myTemplate}">
<ListBox.Resources>
<DataTemplate x:Key="myTemplate" DataType="{x:Type local:MyListBoxItem}">
<Label Foreground="Green" Content="{Binding Title}" Tag="{Binding IsAvailable}">
<Label.Style>
<Style TargetType="{x:Type Label}">
<Style.Triggers>
<DataTrigger Binding="{Binding Tag, RelativeSource={RelativeSource Self}}" Value="True">
<Setter Property="FontWeight" Value="Bold"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Label.Style>
</Label>
</DataTemplate>
... (more datatemplates)
</ListBox.Resources>
</ListBox>
My question: In my solution the value of IsAvailable "goes through" two bindings. The first one binds the value to the Tag property of the Label and then in the style triggers, a trigger checks its value and sets a property of the Label. When I used Binding="{Binding IsAvailable, RelativeSource={RelativeSource AncestorType={x:Type local:MyListBoxItem}}}" it didn't work, because the Style can't see any ancestor of the Label (or something similar reason), it resulted binding errors (with code 4 or 40 maybe), for each item added to the ListBox.
So finally: can I make the solution more simple, or there is no another (better) one?
An important thing I've forgot to mention, sorry: I put the DataTemplate in the ListBox's resources because I have more templates (they are basically differ, so I can't style them with triggers), which I have to switch between sometimes...
The ItemTemplate will take the type that the ItemsSource is bound to. Therefore you should be able to simply bind to IsAvailable, as the ListBox's item type is MyListBoxItem. Try this:
<ListBox ItemsSource="...">
<ListBox.ItemTemplate>
<DataTemplate>
<Label Foreground="Green" Content="{Binding Title}" Tag="{Binding IsAvailable}">
<Label.Style>
<Style TargetType="{x:Type Label}">
<Style.Triggers>
<DataTrigger Binding="{Binding Tag, RelativeSource={RelativeSource Self}}" Value="True">
<Setter Property="FontWeight" Value="Bold"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Label.Style>
</Label>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
You'll need to set your ItemsSource property to a Binding to the MyListBoxItem collection.