更新ComboBox所选项目

Question

I have a ComboBox that is that is being populated from an ItemsSource collection. I am populating all the customers into an Observable Collection, and binding it to the collection, like so.

<ComboBox ItemsSource="{Binding Path=Customers}"
          SelectedValue="{Binding CustomerKey}"
          DisplayMemberPath="FullName" SelectedValuePath="{Binding Key}" />

In this same view, I have a data grid with basic information with orders in it. When an order is selected, within the view model I am getting a more detailed record for the order. What I want to do is update the view with customer information for the newly selected order.

I was trying to set the CustomerKey , and then selected that Customer based on it's key -- I think I am doing this all wrong though. How can I accomplish this?

Answer 1

The SelectedValuePath property of the ComboBox should be set to a string (and not to a binding) that specifies the name of the property of the Customer class where the key is stored:

<ComboBox ItemsSource="{Binding Path=Customers}"
          SelectedValue="{Binding CustomerKey}"
          DisplayMemberPath="FullName" SelectedValuePath="Key" />

This will work provided that the Customer class has a FullName and a Key property and that the Key property has the same type as the CustomerKey property of the view model.

A customer with a key matching the value that you set the CustomerKey property to must also be present in the Customers collection that you bind the ComboBox to for an item to be selected.