ComboBox中的默认选定值

Question

Im trying to set default value of ComboBox . I'm using binding in layout and I'm not sure how bind it right. Here is my viewModel :

public class ViewModel : INotifyPropertyChanged
{
    private Sklady sklady = null;

    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }

    public Sklady Sklady
    {
        get
        {
            return this.sklady;
        }
        set
        {
            this.sklady = value;
            NotifyPropertyChanged("Sklady");
        }
    }
}

How I am set data to viewModel :

private void comboBoxSklad_Loaded(object sender, RoutedEventArgs e)
{
    //get some data
    prijemWindow.viewModel.Sklady = sklady;
    prijemWindow.viewModel.Sklady.skladID = prijemWindow.viewModel.Radky.radky[index].SKLAD;
}

My viewModel use this class to get values:

[DataContract]
public class Sklady
{
    [DataMember]
    public List<Sklad> sklady { get; set; }
    [DataMember]
    public String skladID { get; set; }

    public class Sklad
    {
        public string ID { get; set; }
        public string NAME { get; set; }
        public string CODE { get; set; }
    }
}

And this is current xaml code:

<ComboBox Name="comboBoxSklad" Loaded="comboBoxSklad_Loaded" ItemsSource="{Binding Sklady.sklady}" DisplayMemberPath="CODE"
        SelectedValuePath="ID" SelectedItem="{Binding Sklady.skladID}"/>

Data are binded into ComboBox correctly and I can see data from sklady List . But I would like to set the ComboBox default value to skladID value. How can I do it?

ANSWER

With answer from Klaus Byskov Pedersen I get it work... First, I use SelectedValue instead of SelectedItem ... Then, I ininialize Sklady in constructor prijemWindow.viewModel.Sklady = new Sklady();prijemWindow.viewModel.Sklady = new Sklady(); and at the end, changed lines :

sklady.skladID = prijemWindow.viewModel.Radky.radky[index].SKLAD;
prijemWindow.viewModel.Sklady = sklady;

Thanks a lot!

Answer 1

Use SelectedValue instead of SelectedItem .

<ComboBox Name="comboBoxSklad" Loaded="comboBoxSklad_Loaded" ItemsSource="{Binding Sklady.sklady}" DisplayMemberPath="CODE"
    SelectedValuePath="ID" SelectedValue="{Binding Sklady.skladID}"/>

When using SelectedItem the bound item would be of type Sklady , not string .

EDIT `

prijemWindow.viewModel.Sklady = sklady;
prijemWindow.viewModel.Sklady.skladID = prijemWindow.viewModel.Radky.radky[index].SKLAD;

You have a NotifyPropertyChanged when you set viewModel.Sklady but at the time this is fired, you have not yet set the skladID so try changing the order of those two statements.