WPF listbox groupping by substrings - wpf

Question

My object has property that stores more strings separated by separator.
I want to display list of such objects in WPF listbox with grouping enabled. What I need is to have groups according to substrings.
Object1: Property = "string1;string2;string3"
Object2: Property = "string2;string3"
I expect listbox to be displayed like that:
string1
Object 1
Object 2
string2
Object 1
string3
Object 1
Object 2
Is that possible?
Thank you for your help.

Answer 1

Create a wrapper class.
class MyGroup
{
public string GroupID;
public object SomeObject;
}
Build your flat list of that wrapper class.
private List<MyGroup> BuildItemsSourceTogether()
{
List<MyGroup>itemsSource = new List<MyGroup>();
foreach(var obj in myListWithObjectsWhichPropertiesAreStringsWhichFuthermoreContainSubstrings)
{
var stringArray = obj.Property123.Split(';');
foreach(var str in stringArray)
{
itemsSource.Add(new MyGroup () { GroupID = str, SomeObject = obj});
}
}
return itemsSource;
}
Tell what property in your wrapper class should be used for grouping.
class Window1
{
public Window1()
{
InitalizeComponents();
var finalData = new ListCollectionView(BuildItemsSourceTogether());
finalData.GroupDescriptions.Add(new PropertyGroupDescription("GroupID"));
this.DataContext = finalData;
}
}
In XAML set the look of your groups and let WPF group that flat list of IDs for you.
I used a DataGrid with columns. You can use a ListBox.
<DataGrid ItemsSource="{Binding}">
<DataGrid.GroupStyle>
<GroupStyle>
<GroupStyle.HeaderTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Path=Name}" />
</StackPanel>
</DataTemplate>
</GroupStyle.HeaderTemplate>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type GroupItem}">
<Expander>
<Expander.Header>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Name}" />
<TextBlock Text="{Binding Path=ItemCount}"/>
<TextBlock Text="Items"/>
</StackPanel>
</Expander.Header>
<ItemsPresenter />
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
</DataGrid.GroupStyle>
<DataGrid.Columns>
<DataGridTextColumn Header="header1" Binding="{Binding SomeObject.Property321}" />
<DataGridTextColumn Header="header2" Binding="{Binding SomeObject.Property678}" />
</DataGrid.Columns>
</DataGrid>
Have fun.