Validate the selected value in a WPF combobox

Question

Like the title says, I am trying to validate my form, but I have an issue getting the combobox value:

Answer 1

Stupid, stupid stupid lack of observation on my part. If you were to change the ComboBox's Text to SelectedValue instead like so:

<ComboBox Name="ComboBox_Pais" 
          Validation.Error="Validation_Error"
          SelectedValue="{Binding UpdateSourceTrigger=PropertyChanged, 
                                  Path=Escuela_Pais,
                                  ValidatesOnDataErrors=true, 
                                  NotifyOnValidationError=true}"/>

One will get the selected value and NOT the text.

For those of you who might want to read on it, I found the original tutorial here.

WPF TextBox Validation with IDataErrorInfo