WPF Combobox binding Question

Question

I have a 2 Table.

Product
ProductName
CategoryID

Category
ID
CategoryName

I'm filling combobox to table named 'category'.

Code

Product currentProduct=datacontext.products.FirstOrDefault();
this.datacontext=currentProduct;
combobox1.Itemssource=datacontext.categories;

XAML

<Textbox Text="{Binding Path=ProductName}"></Textbox>
<Combobox x:Name="combobox1" SelectedItem="Binding Path=CategoryID"></Combobox>

When click save button, I'm doing datacontext.SubmitChanges()

ProductName changed. But CategoryID not changed.

My target is when i select from combobox, selected category ID set to CategoryID of currentProduct. (like currentProduct.CategoryID=(Category as combobox1.SelectedItem).ID)

How to do is from xaml?

Answer 1

Bind the SelectedValue property of the ComboBox to the CategoryID of the product, not the SelectedItem. You also need to set the SelectedValuePath property :

<Combobox x:Name="combobox1" SelectedValuePath=CategoryID, SelectedValue="{Binding Path=CategoryID, Mode=TwoWay}"></Combobox>