Setting up validation with DevExpress XtraEditors combobox

DevExpress gives a lot of features for the amount of money that you are required to spend. Fact. I like the way everything looks so consistent.

So generally for all controls:

• Drag and drop DxValidationProvider onto your form.
  
• Click the provider.
• Set validation mode to manual.
  
• You will also be get a smart tag for "Customize Validation Rules"
• Select your control and setup the validation rules.
• When you want to validate (e.g. on OK button) use something like the following code:
  

dxValidationProvider1.Validate();
if(dxValidationProvider1.GetInvalidControls().Count!=0)
return;
this.DialogResult = DialogResult.OK;
this.Close();

Done :)

Now for setting up a combobox with valid values as no values along with a list do the following:

• Select your combobox
• In its properties expand the properties section.
• set your selectables in its items collection (with a blank newline as the first line for the empty string)
• Delete its edit value
• Launch its validation editor (from DxValidationProvider).
• Set "Contition Validation" along with "Conditional Operator" as "AnyOf". Edit the values and paste the same items as you did in the items collection.
  

Enjoy!