Silverlight combobox SelectedItem binding issue

I am new to .NET, and is working on my first Silverlight application.

I Have a Silverlight Child window which is used to add new Customers to a gridview, and has the following code:

namespace FrontEnd.Views
{
    public partial class NewCustomer : ChildWindow
    {
        public DataTransfer.Customer MyCustomer { get; set; }

        public NewCustomer()
        {
            InitializeComponent();
            MyCustomer = new DataTransfer.Customer();
            NewCustomerForm.CurrentItem = MyCustomer;
            NewCustomerForm.BeginEdit();
        }

        private void OKButton_Click(object sender, RoutedEventArgs e)
        {
            NewCustomerForm.CommitEdit();
            this.DialogResult = true;
        }

        private void CancelButton_Click(object sender, RoutedEventArgs e)
        {
            MyCustomer = null;
            NewCustomerForm.CancelEdit();
            this.DialogResult = false;
        }
    }
}



<dataform:DataForm x:Name="NewCustomerForm" Header="New Customer" AutoGenerateFields="False" Margin="0,12,0,0" MinWidth="290" HorizontalAlignment="Left">
            <dataform:DataForm.EditTemplate>
                <DataTemplate>
                    <StackPanel>
                        <dataform:DataField Label="First name">
                            <TextBox Text="{Binding Firstname, Mode=TwoWay}"/>
                        </dataform:DataField>
                        <dataform:DataField Label="Last name">                         
                            <ComboBox x:Name="cb1" SelectedItem="{Binding Lastname, Mode=TwoWay}">
                                <ComboBoxItem Content="NameOne"></ComboBoxItem>
                                <ComboBoxItem Content="NameTwo"></ComboBoxItem>
                            </ComboBox>
                        </dataform:DataField>
                    </StackPanel>
                </DataTemplate>
            </dataform:DataForm.EditTemplate>
        </dataform:DataForm> 

The MyCustomer object contains a Firstname and a Lastname property.

Just for testing purposes i want to add the Lastname through a combobox, the probl开发者_如何学Pythonem is however, when i bind the Lastname property to the combobox selected item, the value that gets saved to the Lastname property is the string System.Windows.Controls.ComboBoxItem instead of the SelectedItem text value.

How can i save the text from the selectedItem in the combobox to the Lastname property?

try this

<ComboBox x:Name="cb1" SelectedValue="{Binding Lastname, Mode=TwoWay}" SelectedValuePath="Content">

Use ComboBoxName.items.SelectedBoxItem

that is SelectedBoxItem instead of SelectedItem