Multi Select Dropdown throwing an error when Select ALL is clicked

Radzen.Blazor Components
1

Hello,

I am not sure if I am doing something wrong because it DOES work on your demo but not on my end.

I have created a simple app to reproduce the error I am having in another app I am working on:

image
image502×561 26.9 KB

When I click select all from a multi-select Dropdownlist it throws the following error:

[2022-12-15T02:40:54.860Z] Error: System.InvalidCastException: Unable to cast object of type 'System.Linq.EnumerableQuery1[System.String]' to type 'System.String'. at Radzen.DropDownBase1.SelectAll()
at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)

However, when I click one by one it does work as expected

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image661×612 33.1 KB

I appreciate any help!

3 
@page "/"

<PageTitle>Index</PageTitle>

<h1>Hello, world!</h1>

<RadzenDropDown AllowClear="true" AllowFiltering="true" FilterCaseSensitivity="FilterCaseSensitivity.CaseInsensitive"
      Multiple="true" Placeholder="Select..." AllowSelectAll=true Data=@stringList TValue="string"   />

@code
{
    public string[] stringList = { "Item1", "Item2", "Item3" };
}
4

This should be IEnumerable - you might need to check carefully our demos.

5

@enchev I tried with an IEnumerable as well and it still throwing the same error as before:

6 
@page "/"

<PageTitle>Index</PageTitle>

<h1>Hello, world!</h1>

<RadzenDropDown AllowClear="true" AllowFiltering="true" FilterCaseSensitivity="FilterCaseSensitivity.CaseInsensitive"
                @bind-Value=@dropdownTestsresults Multiple="true" Placeholder="Select..." Data=@data TextProperty="TextProperty" ValueProperty="ValueProperty"
                Class="w-100" />

@code {

    public class TestDro
    {
        public string TextProperty { get; set; }

        public string ValueProperty { get; set; }
    }

    IEnumerable<TestDro> dropdownTestsresults;


    public class DropDownTest
    {
        public string TextProperty { get; set; }
        public string ValueProperty { get; set; }
    }


    DropDownTest[] dropDownTests = new DropDownTest[]
    {
        new DropDownTest(){ TextProperty="Text1", ValueProperty = "Value1"},
        new DropDownTest(){ TextProperty="Text2", ValueProperty = "Value2"}

    };

    public IEnumerable<DropDownTest> GetAllValues()
    {
        return dropDownTests;
    }


    public IEnumerable<DropDownTest> data { get; set; }

    protected override async Task OnInitializedAsync()
    {
        data = GetAllValues();
    }

}
7

image
image625×633 32.4 KB

Same error

8

Looks like you didn’t checked the demos at all. It should be IEnumerable since your ValueProperty is a string.