Trying to learn how to bind objects to various types of controls. In this instance, I want to get sample data in my object to appear in ComboBox. The code runs but what appears instead of values (David, Helen, Joe) is text "TheProtect.UserControls.Client")
XAML: (ucDataBindingObject.xaml)
<UserControl x:Class="TheProject.UserControls.ucDataBindingObject"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
Width="Auto"
Height="Auto"
mc:Ignorable="d">
<Grid Width="130"
Height="240"
Margin="0">
<ComboBox Width="310"
HorizontalAlignment="Left"
VerticalAlignment="Top"
ItemsSource="{Binding Path=Clients}" />
</Grid>
</UserControl>
C#: ucDataBindingObject.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Controls;
namespace TheProject.UserControls
{
public partial class ucDataBindingObject : UserControl
{
public List<Client> Clients { get; set; }
public ucDataBindingObject()
{
Clients = new List<Client>();
Clients.Add(new Client(1, "David")); // sample data
Clients.Add(new Client(2, "Helen"));
Clients.Add(new Client(3, "Joe"));
InitializeComponent();
this.DataContext = this;
}
}
C# Client.cs
using System;
using System.Linq;
namespace TheProject.UserControls
{
public class Client
{
public int ID { get; set; }
public string Name { get; set; }
public Client(int id, string name)
{
this.ID = id;
this.Name = name;
}
}
}
There are several ways to tell the framework what to display
1) Use DisplayMemberPath
on the ComboBox (this will display the named property):
<ComboBox ItemsSource="{Binding Path=Clients}"
DisplayMemberPath="Name"
/>
2) Set ItemTemplate
on the ComboBox. This is like #1, except allows you to define a template to display, rather than just a property:
<ComboBox ItemsSource="{Binding Path=Clients}">
<ComboBox.ItemTemplate>
<DataTemplate>
<Border BorderBrush="Green" BorderThickness="1" Padding="5">
<TextBlock Text="{Binding Path=Name,StringFormat='Name: {0}'}" />
</Border>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
3) Add a ToString()
override to source class. Useful if you always want to display the same string for a given class. (Note that the default ToString()
is just the class type name, which is why you see "TheProtect.UserControls.Client".)
public class Client
{
// ...
public override string ToString()
{
return string.Format("{0} ({1})", Name, ID);
}
}
4) Add a DataTemplate
to the XAML resources. This is useful for associating a given class type with a more complex or stylized template.
<UserControl xmlns:local="clr-namespace:TheProject.UserControls">
<UserControl.Resources>
<DataTemplate DataType="local:Client">
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</UserControl.Resources>
// ...
</UserControl>