Required Field Validation for DropDown fields

In the recent release, we have included a required field validation for DropDown fields. This feature has only been added for the DetailsView control.

Property Name	Allowed Values	Description
IsRequired	True/False	Set to True if you want the field to be a required   field
IsRequiredInitialValue	String	This property is used to specify the initial value   for the field and compare if the field value has changed. ** Only valid if IsRequired   = True

This  post will teach you how to :

• Setup required field validation for dropdown field
• Changing value for selected text

Setting up Required Field validation
Step 1 : Add a DetailsView with DropDown field

Step 2 : Set IsRequired field property to ‘True’

Result :

• A validation message is displayed when the ‘Save’ button is clicked.
  

Changing value for selected value in dropdown field
Step 1 : Set IsRequiredInitialValue to ‘I need to change this’

Result :

• Selected value will be ‘I need to change this’
  
• A validation message is displayed if user does not select a different value
  

Step 2 : Set IsRequiredInitialValue  property as blank

Result

• Selected value will be blank
  

Additional information

1. You cannot change the validation message.
2. You can use Custom Setting / Page Parameter / System Variable / SQL Query to specify IsRequiredInitialValue text.
3. If IsRequiredInitialValue is populated, DefaultValue will be overridden