具有DisplayValue和SelectValue的WPF组合框无法正常工作

Question

I guess I'm missing something here and I hope someone can help me out. I have this class I'm using in Entity Framework:

    public VendorDetail()
    {
        public long VendorID { get; set; }
        public string VendorName { get; set; }
        public string Address { get; set; }
    }

In SQL Server 2008, I have this table called PartsList that has a foreign key relationship with the VendorDetail table.

In the XAML, I have a Datagrid:

   <Grid DataContext="{StaticResource PartsListsSource}">
    <DataGrid x:Name="partsListsDataGrid" AutoGenerateColumns="False" EnableRowVirtualization="True"
            ItemsSource="{Binding}"
            RowDetailsVisibilityMode="VisibleWhenSelected">
               <DataGrid.Columns>
                   <DataGridTextColumn x:Name="partsListIDColumn" Binding="{Binding PartsListID}"
                    Header="Parts List ID" Width="SizeToHeader" />
                   <DataGridTextColumn x:Name="partIDColumn" Binding="{Binding PartID}" Header="Part ID"
                    Width="SizeToHeader" />
                        <DataGridTemplateColumn x:Name="vendorNameColumn"
                                          Width="Auto"
                                          Header="Vendor Name">
                            <DataGridTemplateColumn.CellTemplate>
                                <DataTemplate>
                                    <ComboBox ItemsSource="{Binding RelativeSource={RelativeSource AncestorType=UserControl}, Path=DataContext.VendorDetails}"
                                              DisplayMemberPath="VendorName"
                                              SelectedValuePath="VendorID"
                                              SelectedItem="{Binding VendorID}"/>
                                </DataTemplate>
                            </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                    <DataGridTextColumn x:Name="vendorPartNoColumn" Binding="{Binding VendorPartNo}"
                        Header="Vendor Part No" Width="SizeToHeader" />
                    <DataGridTextColumn x:Name="descriptionColumn" Binding="{Binding Description}"
                        Header="Description" Width="SizeToHeader" />
                </DataGrid.Columns>
    </DataGrid>
</Grid>

Now all the other columns are working except the ComboBox.

I know the VendorID is a bit confusing, so just to clarify: I've created a list of VendorDetail that I want the ComboBox to use, use the VendorDetail.VendorID and VendorDetail.VendorName, and it set to the PartLists.VendorID which is the Foreign Key to VendorDetail.

So what is it that I'm doing wrong?

Answer 1

Someone in another forum told me the problem. I should use SelectedValue instead SelectedItem. So another words, it should be this:

SelectedValue="{Binding VendorID}"

And that took care of the problem. I thought it was something so simple!