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ValueChanged Error

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DropDownList
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Jonathan
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Jonathan asked on 03 Jun 2020, 03:34 PM

Hi..

What is wrong?  When the value changes I need to set values to other textboxes. What is wrong with my 'tags'?

When I set @bind-value , I get error that I can't have 2 change events.

I also need to bind to FoodType property.

 

thx again!

 

Telerik.Blazor.Components.TelerikDropDownList`2[CKonboard.Data.Models.EventFoodType,System.String] requires a value for the 'ValueExpression' ValueExpression is provided automatically when using 'bind-Value'.
   at Telerik.Blazor.Components.Common.TelerikSelectBase`2.OnInitializedAsync()
   at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()
   at Telerik.Blazor.Components.Common.TelerikSelectBase`2.SetParametersAsync(ParameterView parameters)

 

 <TelerikDropDownList Id="FoodType"
                         ValueChanged="@((string c) => EventSelected(c))"
                         Value="@Service.FoodType"
                         Data="@Lookups.EventFoodTypes()"
                         TextField="EvtType"
                         DefaultText="-Select First Event Food Type"
                         ValueField="EvtType"
                         PopupWidth="200px"
                         Width="200px"
                         PopupHeight="130PX"
                         Class="ddl-no-bg">

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Marin Bratanov
Telerik team
answered on 03 Jun 2020, 03:43 PM

Hi Jonathan,

You can read more about the error and its solutions in this article: https://docs.telerik.com/blazor-ui/knowledge-base/requires-valueexpression

When using the <Parameter>Changed event, you can use @bind-<Parameter>, that's how the framework operates.

 

Regards,
Marin Bratanov
Progress Telerik

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Marin Bratanov
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