WPF: ComboBox displays "(namespace).(classname)" instead of data

Question

I want to get my ComboBox in XAML to bind to my List collection of custom objects in code behind.

Currently the ComboBox lists for each entry "dpwpf.Contact" which is my {namespace}.{classname}.

What do I need to put in the XAML to tell it to list out, e.g. LastName + FirstName?

I know it's something like {Binding Path=... Value=...} but I can't get it.

XAML:

<Window x:Class="dpwpf.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <StackPanel>
        <StackPanel>
            <TextBlock Text="Select the contact:"/>
            <ComboBox Name="theContactList"/>
        </StackPanel>
    </StackPanel>
</Window>

Code Behind:

namespace dpwpf
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            StoreDB db = new StoreDB();
            List<Contact> contacts = db.GetContacts()
            theContactList.ItemsSource = contacts.ToList();
        }
    }
}

Answer:

<Window x:Class="dpwpf.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300"
    xmlns:local="clr-namespace:dpwpf">

    <Window.Resources>
        <DataTemplate DataType="{x:Type local:Contact}">
            <StackPanel Orientation="Horizontal">
                <TextBlock Text="{Binding LastName}"/>
                <TextBlock Text=" "/>
                <TextBlock Text="{Binding FirstName}"/>
            </StackPanel>
        </DataTemplate>
    </Window.Resources>

    <StackPanel>
        <StackPanel Margin="10">
            <TextBlock Text="Contact Name:" Foreground="#555"/>
            <TextBox Name="theName"/>
        </StackPanel>
        <StackPanel>
            <TextBlock Text="Select the contact:"/>
            <ComboBox Name="theContactList"/>
        </StackPanel>
    </StackPanel>
</Window>

Answer 1

you need to use DisplayMember="TheValue"

you can add this in the XAML or in the CLR also note your binding in cose and not through the XAML. i think this relates to a prvious question of yours. which implements the binding through ObjectDataProvider use that example and add the DisplayMemeber="memeber" in the XAML

HTH, Eric,

Answer 2

Hi Edward

What the binding mechanism is doing is calling ToString() on the type that is being bound. Because I guess you're not overriding ToString() it'll just so the namespace.type instead of something useful.

As rebelious says, you can use DisplayMember to tell the binding to use a property of that name for the display value or you can override ToString() as below to get your custom property to show.

public void Contact
{
 public string FirstName { get; set; }
 public override string ToString()
 {
   return FirstName; 
 }
}

Answer 3

You can override the ToString method of Contact, or you can define a DataTemplate in WPF.

xmlns:dpwpf="... namespace of dpwpf"

<Window.Resources>
    <DataTemplate DataType="{x:Type dpwpf:Contact}">
        <StackPanel Orientation="Horizontal">
            <TextBlock Text="{Binding LastName}">
            <TextBlock Text=" ">
            <TextBlock Text="{Binding FirstName}">
        </StackPanel>
    </DataTemplate>
</Window.Resources>

This allows you to define how a Contact object will appear anywhere in the window. If you want to limit this to the ComboBox you can add the DataTemplate just to the ComboBox resources.

See also What does "{Binding}" mean? by Bea Stollnitz

Answer 4

Just add this in you ComboBox tag (xaml code)

TextSearch.TextPath ="Title"

ToString() modification affects all future cases you need it, I don't recommend you to do that.

See that example: http://simplesample.site90.com/wpf_combobox.php