Distinct Values in WPF Combobox

Question

I would like to get distinct values in my databound combo box

as an example the values it has are: blue, blue, yellow, red, orange

I would like it to just di

Answer 1

Let's say your you have a List<String> values = blue, blue, yellow, red, orange

you can do

ComboBox.ItemsSource = values.Distinct();

or if you are going for MVVM approach you can create a property and bind combo box itemssource with a property like

public List<string> values
{
    get
    {
    return value.Distinct();
     }
}

Answer 2

You could create an IValueConverter that converts your list into a distinct list:

public class DistinctConverter : IValueConverter
{
    public object Convert(
        object value, Type targetType, object parameter, CultureInfo culture)
    {
        var values = value as IEnumerable;
        if (values == null)
            return null;
        return values.Cast<object>().Distinct();
    }

    public object ConvertBack(
        object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

add this to resources:

<local:DistinctConverter x:Key="distinctConverter" />

and use it like this:

<ComboBox ItemsSource="{Binding Vals, Converter={StaticResource distinctConverter}}" />

Answer 3

if you are using WPF c# 4.0

List<object> list = new List<object>();
        foreach (object o in myComboBox.Items)
            {
            if (!list.Contains(o))
                {
                list.Add(o);
                }
            }
        myComboBox.Items.Clear();
        myComboBox.ItemsSource=list.ToArray();