In a WPF form, using C#, how do I set a ComboBox using the Tag

Question

I have this combobox on a WPF form

Settings.xaml

<ComboBox x:Name="cboKioskType" HorizontalAlignment="Right" Margin="0,0,0,0" SelectedValuePath="Tag">
    <ComboBoxItem IsEnabled="False" IsSelected="True" Tag="empty" Content="Select Kiosk Type" />
    <ComboBoxItem Tag="spd" Content="SPD"/>
    <ComboBoxItem Tag="vendor" Content="Vendor"/>
</ComboBox>

I also have a custom object that is populated from XML, and I'm trying to use the value from that to set my ComboBox Selected

ComputerSetting.cs

namespace Kiosk
{
    public class ComputerSetting
    {
        [XmlAttribute("computer_type")]
        public string ComputerType { get; set; }
    }
}

Settings.xaml.cs

namespace Kiosk
{
    public partial class Settings : Window
    {
        internal ComputerSetting ComputerSettings = new ComputerSetting();
    }

    internal void SetSettingsFields()
    {
        cboKioskType.SelectedItem = this.ComputerSettings.ComputerType;
    }
}

The xml works, and the TextBox fields I have on the Settings form all get the values from the XML as expected. But I can't figure out how to get the ComboBox to work properly.

I assume I'm not using the SelectedValuePath on the ComboBox the correct way.

Answer 1

Try This Way

public class ComputerSetting
{
    public string ComputerType;
}


public class ComputerList
{
    [XmlElement("ComputerSettings")]
    public List<ComputerSettings> Computers;
}


var computers = (ComputerList)new XmlSerializer(typeof(ComputerList)).Deserialize(stream);
cboKioskType.ItemsSource = computers.ComputerSettings;


<ComboBox x:Name="cboKioskType" IsReadOnly="False" HorizontalAlignment="Left" IsEditable="True" DisplayMemberPath="ComputerType">

Answer 2

The answer is that I should have used

cboKioskType.SelectedValue = this.ComputerSettings.ComputerType;

not

cboKioskType.SelectedItem = this.ComputerSettings.ComputerType;

NB For this situation data binding isn't appropriate, which is why I'm using a more manual method to set the fields. The code I've given was simplified for this question, so it's obvious that I shouldn't be using binding.