Validation is not working for dropdown

HI I am trying to validate for required value selected in dropdown but does not seem to be working for me

<RadzenDropDown Data="@controlClassifications" TextProperty="Classification" ValueProperty="ClassificationId" @bind-Value="@((newControl.ClassificationId))" Name="Class" />
RadzenRequiredValidator Component="Class" Text="Classification is required" />

Any suggestions are appreciated

Thank you


Hi @chebyr,

Did you put the DropDown and RequiredValidator inside a RadzenTemplateForm component? Radzen validators work only inside a RadzenTemplateForm.

yes I have

RequiredValidator works for textboxes but does not work for dropdowns

Hi, I have the same problem. How I can validate DropDown. Thanks

Check the type for binding value.
If it integer, validation will be always sucseeded.
It must be nullable type


You can set the DefaultValue property of the RequiredValidator - it specifies the value which should check against - using 0 for a numeric should work. Of course if 0 is a valid value you would need a nullable property as suggested by @Simon_Postford.


Thanks for tips. On the end I set default value to object, and then the drop down does not contains empty value.

Using RBS the RadzenRequiredValidator is not working for a dropdown component where the value property is a uniqueidentifier...

           <RadzenFormField Text="Application" Variant="Variant.Filled">
                    <RadzenDropDown Data="@applicationsForApplicationId" TextProperty="Name" ValueProperty="ApplicationId" AllowClear=true
                          @bind-Value="@permission.ApplicationId" Name="ApplicationId" Style="width: 100%" />
                    <RadzenRequiredValidator Component="ApplicationId" Text="Application is required" />                 

Hi @semafox,

It won't work as Guids have a default value (Guid.Empty). Try setting the DefaultValue attribute of RadzenRequiredValidator to Guid.Empty:

<RadzenRequiredValidator DefaultValue=@(Guid.Empty) ... />

Thank you, that was the solution!