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binding to an object on a data template [duplicate]

I define a headertemplate into a wpf groupbox and the databinding doesn't work. I don't understand why.
<GroupBox>
<GroupBox.HeaderTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" >
<Image Source="/PopuAssuNetApplication.UI.Control;component/Images/Members.png" Width="24" />
<TextBlock VerticalAlignment="Center">
<TextBlock.Text>
<MultiBinding StringFormat="{x:Static Member=resx:Resources.PersonsInContractGroupBox}">
<Binding Path="CurrentContract.Federation" RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type GroupBox}}">
</Binding>
<Binding Path="CurrentContract.Type" Converter="{StaticResource contractTypeConverter}" RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type GroupBox}}">
</Binding>
<Binding Path="CurrentContract.Number" RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type GroupBox}}">
</Binding>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
<WpfComponent:WaitControl Margin="7,0,0,0" VerticalAlignment="Top" Width="24" Height="24" MarginCenter="4">
<WpfComponent:WaitControl.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsMembersOfContractBusy, UpdateSourceTrigger=PropertyChanged, ElementName=PersonsInContract}" Value="true">
<Setter Property="WpfComponent:WaitControl.Visibility" Value="Visible" />
</DataTrigger>
<DataTrigger Binding="{Binding Path=IsMembersOfContractBusy, UpdateSourceTrigger=PropertyChanged, ElementName=PersonsInContract}" Value="false">
<Setter Property="WpfComponent:WaitControl.Visibility" Value="Collapsed" />
</DataTrigger>
</Style.Triggers>
</Style>
</WpfComponent:WaitControl.Style>
</WpfComponent:WaitControl>
</StackPanel>
</DataTemplate>
</GroupBox.HeaderTemplate>

The problem is that the HeaderTemplate is used for templating the Header thus within the HeaderTemplate your DataContext is whatever you bind or assign to the Header property of your GroupBox.
Think of the Header property as almost like the DataContext for the header of the control. Normally the DataContext property inherits its value from its parent but since not every control has a Header the Header is blank unless you set it.
By binding your Header explicitly to the current DataContext Header="{Binding}" your example should work as you expect. To help illustrate how this works I've created a simple example below that shows how the Header and DataContext work independently from each other for providing data to either the body or header of the control.
<GroupBox Header="HEADER TEXT" DataContext="BODY TEXT">
<GroupBox.HeaderTemplate>
<DataTemplate>
<Button Content="{Binding}"
Background="LightGreen" />
</DataTemplate>
</GroupBox.HeaderTemplate>
<CheckBox HorizontalAlignment="Center"
VerticalAlignment="Center" Content="{Binding}" />
</GroupBox>
This will yield a GroupBox that looks like the following.
I think that by default in databinding, wpf always gets data from the DataContext property. Seems not in datatemplate
Your assumption is correct about DataContext and it does work in the DataTemplate as I've demonstrated it's just that in the Header's template the DataContext is the value from the Header Property and not the DataContext itself.

The GroupBox does not have a member called "CurrentContract". Most probably, you want to accesss a property called "CurrentContract" from the corresponding ViewModel?! The ViewModel is the GroupBox's DataContext, so you have to change the Binding Paths to something like...
<Binding Path="DataContext.CurrentContract.Type" Converter="{StaticResource contractTypeConverter}" RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type GroupBox}}">

<GroupBox >
<GroupBox.HeaderTemplate>
<DataTemplate>
<RadioButton Content="myR"
IsChecked="{Binding rIsChecked, Mode=TwoWay}"
DataContext="{Binding DataContext, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type GroupBox}}}" />
</DataTemplate>
</GroupBox.HeaderTemplate>
<GroupBox.Content>
<Grid IsEnabled="{Binding rIsChecked}">
</Grid>
</GroupBox.Content>
</GroupBox>
Just propagate the GroupBox DC to the DataTemplate content...works like a charm...

The lesson learned above is useful in general for DataTemplates, but I actually found out recently there is a better way to change the header of a groupbox:
<GroupBox>
<GroupBox.Header>
<CheckBox IsChecked="{Binding Path=mSomeBoolean}"/>
</GroupBox.Header>
</GroupBox>
This way there is no need to define a relative source in the bindings.
Also please note this issue with GroupBoxes and the header.

This is what worked for me:
<HeaderedContentControl Header="{Binding}" Style="{StaticResource TallHeaderedContentStyle}">
<HeaderedContentControl.HeaderTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=HeaderText"} />
</DataTemplate>
</HeaderedContentControl.HeaderTemplate>

How to avoid repeating blocks of XAML in a menu

I have to create a menu. It has 10 entries and they differ by one parameter.
Entry 1:
<MenuItem Visibility="{Binding MenuSelected.Type, Converter={StaticResource TypeToVisibilityConverter}, ConverterParameter='PAZ', Mode=OneWay}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<i:InvokeCommandAction Command="{Binding CmdContextMenu}" CommandParameter="PAZ" />
</i:EventTrigger>
</i:Interaction.Triggers>
<MenuItem.Header>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<TextBlock
Grid.Column="0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontFamily="Segoe MDL2 Assets"
Foreground="{Binding MenuSelected.Type, Converter={StaticResource TypeToColorConverter}, ConverterParameter='PAZ', Mode=OneWay}"
Text="{Binding MenuSelected.Type, Converter={StaticResource TypeToIconConverter}, ConverterParameter='PAZ', Mode=OneWay}" />
<TextBlock
Grid.Column="1"
Margin="{StaticResource XSmallLeftMargin}"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Text="PAZ" />
</Grid>
</MenuItem.Header>
</MenuItem>
Entry 2:
<MenuItem Visibility="{Binding MenuSelected.Type, Converter={StaticResource TypeToVisibilityConverter}, ConverterParameter='APP', Mode=OneWay}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<i:InvokeCommandAction Command="{Binding CmdContextMenu}" CommandParameter="APP" />
</i:EventTrigger>
</i:Interaction.Triggers>
<MenuItem.Header>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<TextBlock
Grid.Column="0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontFamily="Segoe MDL2 Assets"
Foreground="{Binding MenuSelected.Type, Converter={StaticResource TypeToColorConverter}, ConverterParameter='APP', Mode=OneWay}"
Text="{Binding MenuSelected.Type, Converter={StaticResource TypeToIconConverter}, ConverterParameter='APP', Mode=OneWay}" />
<TextBlock
Grid.Column="1"
Margin="{StaticResource XSmallLeftMargin}"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Text="APP" />
</Grid>
</MenuItem.Header>
</MenuItem>
As you can see, the only difference is between PAZ and APP in different points... and same goes on for all the others.
Is there a way I can avoid to repeat it 10 times just changing the 3 letters?
I do not want to use code-behind to create the menu dynamically... but to process it from XAML.

From your question I assume that CmdContextMenu and MenuSelected are properties on your main view model and not in a separate menu item type. If this is different, you have to adapt the code accordingly.
In order to remove the redundant code, create a collection for your menu items in your view model.
public class MyMainViewModel : INotifyPropertyChanged
{
public IEnumerable<string> MyTypes { get; } = new List<string>
{
"PAZ",
"APP"
};
// ...other properties and methods (like "CmdContextMenu" and "MenuSelected" I Assume).
}
Next, you have to change the value converters, because the ConverterParameter is not a dependency property and cannot be bound. Instead, you can use IMultiValueConverters that can bind multiple values. Adapt all of your converters to implement IMultiValueConverter. Here is an example of how a converter could look like. Of course, it depends on your implementation. In essence, use the values array to access bound values.
public class TypeToVisibilityConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
return values[0].Equals(values[1]) ? Visibility.Visible : Visibility.Collapsed;
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
Next, create a data template for the header of your menu items. As you can see, the bindings are replaced with MultiBindings that use an IMultiValueConverter as Converter.
The first binding in each block is a RelativeSource binding to access the data context of the parent Menu, because I assume that the MenuSelected property is defined on your main view model. The other empty bindings will bind to the data context of the current menu item, which is an item from the MyTypes collection.
<DataTemplate x:Key="MyMenuItemHeaderTemplate" DataType="{x:Type system:String}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontFamily="Segoe MDL2 Assets">
<TextBlock.Foreground>
<MultiBinding Converter="{StaticResource TypeToColorConverter}">
<Binding Path="DataContext.MenuSelected.Type" RelativeSource="{RelativeSource AncestorType={x:Type Menu}}" Mode="OneWay"/>
<Binding/>
</MultiBinding>
</TextBlock.Foreground>
<TextBlock.Text>
<MultiBinding Converter="{StaticResource TypeToIconConverter}">
<Binding Path="DataContext.MenuSelected.Type" RelativeSource="{RelativeSource AncestorType={x:Type Menu}}" Mode="OneWay"/>
<Binding/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
<TextBlock Grid.Column="1"
Margin="{StaticResource XSmallLeftMargin}"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Text="{Binding}"/>
</Grid>
</DataTemplate>
Create a new header item style that uses this data template. The Visibility also uses a multi-value converter as above. Instead of using an event trigger, you can simply assign the command to the menu item directly and pass a CommandParameter, which is bound to the data context of the current menu item.
<Style x:Key="MyMenuItemStyle" TargetType="{x:Type MenuItem}" BasedOn="{StaticResource {x:Type MenuItem}}">
<Setter Property="HeaderTemplate" Value="{StaticResource MyMenuItemHeaderTemplate}"/>
<Setter Property="Visibility">
<Setter.Value>
<MultiBinding Converter="{StaticResource TypeToVisibilityConverter}">
<Binding Path="DataContext.MenuSelected.Type" RelativeSource="{RelativeSource AncestorType={x:Type Menu}}" Mode="OneWay"/>
<Binding/>
</MultiBinding>
</Setter.Value>
</Setter>
<Setter Property="Command" Value="{Binding DataContext.CmdContextMenu, RelativeSource={RelativeSource AncestorType={x:Type Menu}}}"/>
<Setter Property="CommandParameter" Value="{Binding}"/>
</Style>
Finally, create a Menu and bind the MyTypes collection, as well as the style.
<Menu ItemsSource="{Binding MyTypes}" ItemContainerStyle="{StaticResource MyMenuItemStyle}"/>

ConverParameter property is not a DependencyProperty - so it cannot be Bound to.
You can use a MultiValue converter instead.
Instead of creating 10 menu items in xaml manually, you should be able to bind an ItemsCollection and define a DataTemplate for MenuItem

How to pass the current row "This" as to a converter parameter

So I have a view, containing a telerik RadGridView, this view is bound to several items, but importantly I need to bind the visibility of an item in one column, to 2 items.
The converter will correctly evaluate the visility, however I need to pass back the previousProc, (currently handled) and also "This" which is a proc as well, just that row.
<telerik:RadGridView Name="ProcedureGrid"
DockPanel.Dock="Left"
SelectionMode="Single"
SelectionUnit="FullRow"
ItemsSource="{Binding Procedures}"
IsReadOnly="True"
AutoGenerateColumns="False"
ShowGroupPanel="False"
ShowColumnHeaders="False"
CanUserReorderColumns ="False"
RowIndicatorVisibility="Collapsed"
Visibility="Collapsed"
Width="200"
FontSize="18"
SelectionChanged="ProcedureGrid_SelectionChanged"
>
<telerik:RadGridView.Columns>
<telerik:GridViewDataColumn Header="Name"
AllowDrop="False"
DataMemberBinding="{Binding Converter={StaticResource langConverter}}"
IsGroupable="False"
IsFilterable="False"
MaxWidth="155"/>
<telerik:GridViewColumn>
<telerik:GridViewColumn.CellTemplate>
<DataTemplate>
<nav:SmallForwardNavigateIcon MaxWidth="30" DockPanel.Dock="Right" Margin="1"
Cursor="Hand" VerticalAlignment="Center" HorizontalAlignment="Center"
MouseDown="SmallForwardNavigateIcon_MouseDown"
Visibility="{Binding RelativeSource={RelativeSource FindAncestor,
AncestorType={x:Type UserControl}},
Path=DataContext.previousProc,
Converter={StaticResource IsPrevProc}}" />
</DataTemplate>
</telerik:GridViewColumn.CellTemplate>
</telerik:GridViewColumn>
</telerik:RadGridView.Columns>
</telerik:RadGridView>
can anyone see where I went wrong and what I could do to fix the xaml to pass both the previousproc and This back

If I understand your UserControl host a telerik:RadGridView control.
Your UserControl has a given DataContext, which seems to conatin a property Procedures, and a property IsPrevProc.
Visibility="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}},Path=DataContext.previousProc,Converter={StaticResource IsPrevProc}}" />
This code seems wrong because you write:
Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}
It means you are looking for properties in your ancestor DataContext, the one containing Procedures and IsPrevProc. So all bindings here have to be with properties of this DataContext. You can't mix in one binding call to different DataContext.
What you could do is create your "previousProc" as a property in this DataContext, so that you can call it directly.
Or you can define "IsPrevProc" as a property of the DataContext of a line of your Grid.
But you can't do both in the same binding.

The ConverterParameter property is not a dependency property and hence can not be bound.
There is however an alternative solution. You could use a MultiBinding with a multi-value converter instead of a normal Binding:
<nav:SmallForwardNavigateIcon MaxWidth="30" DockPanel.Dock="Right" Margin="1"
Cursor="Hand" VerticalAlignment="Center" HorizontalAlignment="Center"
MouseDown="SmallForwardNavigateIcon_MouseDown"
>
<nav:SmallForwardNavigateIcon.Visibility>
<MultiBinding Converter="{StaticResource IsPrevProc}">
<Binding Path="DataContext.previousProc" RelativeSource="{RelativeSource Mode=FindAncestor,
AncestorType=UserControl}"/>
<Binding Path="DataContext.newProc" RelativeSource="{RelativeSource Mode=Self}"/>
</MultiBinding>
</nav:SmallForwardNavigateIcon.Visibility>
</nav:SmallForwardNavigateIcon>
Pass the new proc/this value in second binding.(use relative source if needed)
MultiValue Converter:
public class IsPrevProc : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
//Logic of new proc and Previous Proc
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}

WPF Multibinding .Net Framework 4.0

I have the following DataGridTemplate column:
<DataGridTemplateColumn x:Name="specialtiesColumn" Header="Specialties" MinWidth="170">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding Path=DataContext.Specialties, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType=DataGrid}}">
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Height="17" VerticalAlignment="Center" Orientation="Horizontal">
<CheckBox Width="20">
<CheckBox.IsChecked>
<MultiBinding Converter="{StaticResource ProviderSpecialtyIsInSpecialtiesConverter}">
<Binding RelativeSource="{RelativeSource FindAncestor, AncestorType=ComboBox}" Path="DataContext.Specialties" />
<Binding Path="Name" />
</MultiBinding>
</CheckBox.IsChecked>
</CheckBox>
<TextBlock Text="{Binding Name}" Width="130" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
What I am trying to do is have a column of comboboxes inside a datagrid, and each combobox have several checkboxes. Each row of the datagrid represent hospitals. The combobox will show which specialties the hospital has, and the user should also be able to modify these selections.
This is the code for the converter:
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
try
{
HashSet<Specialty> specialties = (HashSet<Specialty>)values[0];
string specialty = (string)values[1];
foreach (Specialty s in specialties)
{
if (s.Name == specialty)
return true;
}
return false;
}
catch (Exception)
{
return false;
}
}
This works on computers with .Net Framework 4.5, but it crashes when trying to load with only .Net Framework 4.0. The project is targeted for .Net Framework 4.0.

I suppose the reason for that is that the MultiBinding is using the RelativeSource and the DataGridColumn is not a part of visual tree. They must have fixed the column binding behaviour in 4.5. I got the same issue woth my code that looked like this:
<DataGridTextColumn.Binding>
<MultiBinding Converter="{StaticResource directionConverter}">
<MultiBinding.Bindings>
<Binding ElementName="clientPerspective" Path="IsChecked"/>
<Binding Path="Direction"/>
</MultiBinding.Bindings>
</MultiBinding>
</DataGridTextColumn.Binding>`

Command parameter passing parent reference

I Have a WPF treeview and i need the reference of parent node in the child node context.
menu command. In the below XAML, i need to pass the reference of A in member command parameter
XAML:
<DataTemplate x:Key="Member">
<TextBlock Text="{Binding}" Tag="{Binding DataContext, RelativeSource={RelativeSource AncestorType=mylib:ExtendedTreeView}}">
<TextBlock.ContextMenu>
<ContextMenu>
<MenuItem Header="Delete" Command="{Binding RelativeSource={RelativeSource AncestorType=ContextMenu}, Path=PlacementTarget.Tag.DeleteMmeberCommand}">
<MenuItem.CommandParameter>
<MultiBinding Converter="{StaticResource MutilValueConverter}">
<Binding Path=".."/>
<Binding />
</MultiBinding>
</MenuItem.CommandParameter>
</MenuItem>
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</DataTemplate>
<HierarchicalDataTemplate DataType="{x:Type A}" ItemsSource="{Binding Members}" ItemTemplate="{StaticResource Member}"
<TextBlock Text="{Binding"}>
<TextBlock.ContextMenu>
<ContextMenu>
<MenuItem Header="Delete" Command="{Binding RelativeSource={RelativeSource AncestorType=ContextMenu}, Path=PlacementTarget.Tag.DeleteACommand}" CommandParameter="{Binding}"/>
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</HierarchicalDataTemplate>
<TreeView ItemsSource="{Binding As}"/>
Converter:
public class MutilValueConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
return values;
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}

If i understand correctly, you could possibly invert the whole thing:
publish your command in what is your datacontext and give an instance
of your subdatacontext as command parameter (this is just Binding for
your items)

You are using PlacementTaregt in your bindings but you havent set the ContextMenu.PlacementTarget anywhere...
<TextBlock Text="{Binding"} x:Name="MyTextBox">
<TextBlock.ContextMenu>
<ContextMenu PlacementTarget="{Binding ElementName=MyTextBox}">
.....

the straight way is to have viewmodels for what your Members collection is holding.
and with child viewmodels, there is no need for getting in the binding, as you can just hold the data needed in the viewmodel class. it is an adapter between your model (whereever the strings come from) and your view (where the strings are displayed).