Validation is not working for dropdown

Radzen Studio Blazor Server
1

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

2 Likes
2

Hi @chebyr,

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

3

yes I have

RequiredValidator works for textboxes but does not work for dropdowns

4

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

5

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

2 Likes
6

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.

5 Likes
7

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

8

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

           <RadzenFormField Text="Application" Variant="Variant.Filled">
                  <ChildContent>
                    <RadzenDropDown Data="@applicationsForApplicationId" TextProperty="Name" ValueProperty="ApplicationId" AllowClear=true
                          @bind-Value="@permission.ApplicationId" Name="ApplicationId" Style="width: 100%" />
                  </ChildContent>
                  <Helper>
                    <RadzenRequiredValidator Component="ApplicationId" Text="Application is required" />                 
                  </Helper>
            </RadzenFormField>
9

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) ... />
10

Thank you, that was the solution!