Question

Can some one explain and correct the following XAML given the XML File to define the ComboBox ItemsSource?

XAML:

<ComboBox Name="cbConnection" DataContext="{Binding Source=c:\temp\ConnectionList.xml, XPath=DBConnection}" ItemsSource="{Binding XPath=ComboItem}" DisplayMemberPath="Key" SelectedValuePath="Value">

c:\temp\ConnectionList.xml:

<?xml version="1.0" encoding="utf-8" ?>    
<DBConnection>
<ComboItem>
    <Key>Computer-A</Key>
    <Value>Server=COMPA;Database=MyDB;Integrated Security=SSPI;</Value>
</ComboItem>
<ComboItem>
    <Key>Computer-B</Key>
    <Value>Server=COMPB\SQL2012STD;Database=MyDB;Integrated Security=SSPI;</Value>
</ComboItem>
</DBConnection>

Answer 1

You don’t necessarily need to fool around with the DataContext. Just set the ItemsSource appropriately.

1. Set up an XMLDataProvider, and have it read the xml file
   and provide data to other WPF elements. ItemsSource should point to this provider.
2. Add a closing tag to your XML
3. fix your XPath query to query all nodes called ComboItem, not just top level.

Here is the XMLDataProvider, put this in a resource dictionary in your page:

<XmlDataProvider x:Key="XmlData"
                 Source="c:\temp\ConnectionList.xml">
</XmlDataProvider>

Here is the corrected ComboBox:

<ComboBox x:Name="cbConnection"
          ItemsSource="{Binding Source={StaticResource XmlData}, XPath=//ComboItem}"
          DisplayMemberPath="Key"
          SelectedValuePath="Value" />

Here is the corrected XML:

<?xml version="1.0" encoding="utf-8" ?>    
<DBConnection>
    <ComboItem>
        <Key>Computer-A</Key>
        <Value>Server=COMPA;Database=MyDB;Integrated Security=SSPI;</Value>
    </ComboItem>
    <ComboItem>
        <Key>Computer-B</Key>
        <Value>Server=COMPB\SQL2012STD;Database=MyDB;Integrated Security=SSPI;</Value>
    </ComboItem>
</DBConnection>