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Telerik RadComboBox ItemTemplate and MultipleSelectionBoxTemplate

how can i specify MultipleSelectionBoxTemplate which i can access properties of selected items
i have an employee class
public class Employee {
public string Firstname {get;set;}
public string Lastname {get;set;}
}
I am using Telerik radCombobox in my wpf application to display list of employee
<telerik:RadComboBox x:Name="radComboBox"
Width="200"
AllowMultipleSelection="True"
ItemsSource="{Binding Path=EmployeeList}"
>
<telerik:RadComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=Lastname}" />
</DataTemplate>
</telerik:RadComboBox.ItemTemplate>
this works fine for itemtemplate but when i select an item the display text in combobox show name of Employee class not the Lastname
i tried
<telerik:RadComboBox.MultipleSelectionBoxTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=Lastname}" />
</DataTemplate>
</telerik:RadComboBox.MultipleSelectionBoxTemplate>
i get no result , the combobox displayvalue of selected item is always empty.
i tried another solution
<telerik:RadComboBox.MultipleSelectionBoxTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=SelectedItems,Converter={StaticResource SelectionToCustomStringCoverter}}" />
</DataTemplate>
</telerik:RadComboBox.MultipleSelectionBoxTemplate>
this neither work , the converter always execute at first selection
this is really crazy spending 4 hours to figure out a simple thing ,
so my question is how can i specify MultipleSelectionBoxTemplate which i can access properties of selected items .

this neither work , the converter always execute at first selection
You need to bind to a property that is actually set when the selection changes, such as the Count property of the SelectedItems collection.
Try using a multi value converter and a MultiBinding:
<TextBlock>
<TextBlock.Text>
<MultiBinding Converter="{StaticResource SelectionToCustomStringCoverter}">
<Binding Path="SelectedItems" RelativeSource="{RelativeSource AncestorType=telerik:RadComboBox}"/>
<Binding Path="SelectedItems.Count" RelativeSource="{RelativeSource AncestorType=telerik:RadComboBox}"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
You will then get the currently selected items from values[0] in the converter.

Passing incorrect values into MultiValueConverter by MultiBinding

I've been trying to implement a dynamic ToolTip (WPF) for RadioButton (the ToolTip switches, when IsEnabled of the RadioButton changes). I wanted to achieve this with a MultiValueConverter, which would be sort of a general Converter, that accepts 3 values - the IsEnabled value, enabled ToolTip and disabled ToolTip in this exact order.
But sadly I have encountered an issue, that I haven't been able to solve yet. Basically when the code reaches the Convert Method, the Array of values is filled with DependencyProperty.UnsetValue items.
What I managed to find while googling was, that the problem is propably caused by having a wrong DataContext as mentioned here WPF MultiBinding in Convertor fails ==> DependencyProperty.UnsetValue , but I feel like I have tried every combination of RelativeSources and DataContexts, that I could come up with and nothing helped.
Here is the sample code of the View:
<window.Resources>
<local:BooleanToStringConverter x:Key="BooleanToStringConverter"/>
</window.Resources>
<Grid>
<RadioButton x:Name="RadioButton" ToolTipService.ShowOnDisabled="True"
IsEnabled="{Binding IsRadioButtonEnabled}" VerticalAlignment="Center" HorizontalAlignment="Center" Content="Radio">
<RadioButton.ToolTip>
<ToolTip>
<TextBlock>
<TextBlock.Text>
<MultiBinding Converter="{StaticResource BooleanToStringConverter}">
<Binding ElementName="RadioButton" Path="IsEnabled"/>
<Binding RelativeSource="{RelativeSource AncestorType={x:Type local:MainWindow}}" Path="ViewModel.EnabledToolTip"/>
<Binding RelativeSource="{RelativeSource AncestorType={x:Type local:MainWindow}}" Path="ViewModel.DisabledToolTip"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</ToolTip>
</RadioButton.ToolTip>
</RadioButton>
So the result, that I expect from this, is that the correct values will be passed into the Converter (in this case value of IsEnabled and string values of Enabled/Disabled ToolTips).
If anybody has any ideas, I would very much appreciate to hear them :).
Thanks in advance.

I managed to fix this by explicitly setting DataContext on the RadioButton and removing the RelativeSources within the MultiBinding. Though I don't understand why it did not work with the RelativeSources, it works. Here is the code, in case of anyone reading this in the future:
<RadioButton x:Name="RadioButton" ToolTipService.ShowOnDisabled="True"
DataContext="{Binding ViewModel, RelativeSource={RelativeSource AncestorType={x:Type local:MainWindow}}}"
IsEnabled="{Binding IsRadioButtonEnabled}" VerticalAlignment="Center" HorizontalAlignment="Center" Content="Radio">
<RadioButton.ToolTip>
<ToolTip>
<TextBlock>
<TextBlock.Text>
<MultiBinding Converter="{StaticResource BooleanToStringConverter}">
<Binding Path="IsRadioButtonEnabled"/>
<Binding Path="EnabledToolTip"/>
<Binding Path="DisabledToolTip"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</ToolTip>
</RadioButton.ToolTip>
</RadioButton>

Updating the source of a Listbox with a multibinding

I'm trying to get a multi-bound listbox to call the convert back method when items inside it change. Specifically I have a datatemplate that maps each entry to a checkbox and I'd like the source to be updated whenever a box is checked.
<ListBox x:Name="listBoxEdit" Grid.Column="0" Grid.ColumnSpan="2" Grid.Row="3" Height="100" >
<ListBox.ItemsSource>
<MultiBinding Converter="{StaticResource selectedLoadsConverter}" >
<Binding Path="AvailableLoads"/>
<Binding Path="CurrentUnit"/>
</MultiBinding>
</ListBox.ItemsSource>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Content="{Binding Item1}" IsChecked="{Binding Item2}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I know the problem lies in the fact that I'm binding to to the ItemsSource property which is never actually being updated by the checkbox changing, but I can't figure out a good way to push the updates up to the source.

Show multiple columns from database in one combobox

I want to show in one combobox content from two database columns. I would like to show "Name Surname" but I don't know how. I'm working in C# (.NET) using MVVM pattern. "Name" and "Surname" are fields from table "tblGuests".
Thanks in advance,
Vladimir

You could create an ItemTemplate for the ComboBox that binds to all the properties you want to show.
<ComboBox ItemsSource="{Binding}">
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=FirstName}" Padding="10,0,0,0"/>
<TextBlock Text="{Binding Path=LastName}" Padding="10,0,0,0"/>
</StackPanel>
<DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
You could even create a UserControl that can be re-used and use that:
<PersonView>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=FirstName}" Padding="10,0,0,0"/>
<TextBlock Text="{Binding Path=LastName}" Padding="10,0,0,0"/>
</StackPanel>
</PersonView>
<ComboBox ItemsSource="{Binding}">
<ComboBox.ItemTemplate>
<DataTemplate>
<PersonView/>
<DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>

Keep a string list property in Viewmodel,
populate that property in a data loading method, by combining name and surname strings,
bind string property to combo box,
<ComboBox Name="ComboBox1" ItemsSource="{Binding YourStringListProperty}"/>

Another option could be to use MultiBinding something like this
<TextBlock Name="textBox2" DataContext="{StaticResource NameListData}">
<TextBlock.Text>
<MultiBinding Converter="{StaticResource myNameConverter}"
ConverterParameter="FormatLastFirst">
<Binding Path="FirstName"/>
<Binding Path="LastName"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
This code was taken directly from msdn. Refer to it for more details

Compound DisplayMemberPath for a combobox

I need to create a DisplayMemberPath that is a compound of a few properties (ie object.category.Name+" -> "+object.description) I'm pretty sure I can do this by creating a dynamic data type that encapsulates the object and also adds a new property called displayField that is what I need but I'm wondering if there is a more proper way to do this that does not involve creating a new object. Any ideas?

DisplayMemberPath is just a "shortcut" for when you don't need a complex template for items. If you need more control, use ItemTemplate instead:
<ComboBox ItemsSource="{Binding Items}">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="{}{0} -> {1}">
<Binding Path="Category.Name" />
<Binding Path="Description" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>