RadzenDropDown multiple in RadzenGridColumn

panthernet · December 16, 2020, 10:40am

Hi, need help with data binding here. I see the drop down with the list of values but can't check any.

<RadzenGridColumn TItem="SimplifiedAuthEntity" Property="RolesList" Title="@LM.Get("webSettingsSaColumnRoles")">
<EditTemplate Context="order">
    <RadzenDropDown @bind-Value="order.RolesList" Data="@_authRolesList" Style="width:100%" Multiple="true"
                    AllowClear="true" Name="RolesName"/>
    <RadzenRequiredValidator Text="Value is required" Component="RolesName" Popup="true" />
</EditTemplate>

    [Required]
    public IEnumerable<string> RolesList { get; set; } = new List<string>();

    IEnumerable<string> _authRolesList;

It only work one single time if RolesList is null. Once I select the first value, the next click and list becomes irresponsive.

panthernet · December 17, 2020, 1:45pm

I've tried to use simple class for the list with the string property Name and set the TextProperty="Name" on the dropdown box but now I'm getting an error. Radzn.Blazor v2.18.6

IEnumerable<TestClass> _authRolesList;

    public class TestClass
    {
        public long Id { get; set; }
        public string Name { get; set; }
    }

<RadzenDropDown @bind-Value="order.RolesList" Data="@_authRolesList" Style="width: 100%" Multiple="true"
        AllowClear="true" Name="RolesName"  TextProperty="Name" ValueProperty="Name">
</RadzenDropDown>

warn: Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer[100]
      Unhandled exception rendering component: Collection was modified; enumeration operation may not execute.
System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
   at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
   at System.Linq.Enumerable.SelectListIterator`2.MoveNext()
   at System.Linq.Enumerable.CastIterator[TResult](IEnumerable source)+MoveNext()
   at Radzen.DropDownBase`1.SelectItemFromValue(Object value)
   at Radzen.DropDownBase`1.OnParametersSetAsync()
   at Microsoft.AspNetCore.Components.ComponentBase.CallOnParametersSetAsync()
   at Microsoft.AspNetCore.Components.ComponentBase.SetParametersAsync(ParameterView parameters)
   at Radzen.RadzenComponent.<>n__0(ParameterView parameters)
   at Radzen.RadzenComponent.SetParametersAsync(ParameterView parameters)
   at Radzen.DropDownBase`1.SetParametersAsync(ParameterView parameters)
   at Radzen.Blazor.RadzenDropDown`1.SetParametersAsync(ParameterView parameters)
fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
      Unhandled exception in circuit 'jNxGKLA069-ja4BoOanzbQpo0PByd9GfKpdzLzcA-_0'.
System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
   at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
   at System.Linq.Enumerable.SelectListIterator`2.MoveNext()
   at System.Linq.Enumerable.CastIterator[TResult](IEnumerable source)+MoveNext()
   at Radzen.DropDownBase`1.SelectItemFromValue(Object value)
   at Radzen.DropDownBase`1.OnParametersSetAsync()
   at Microsoft.AspNetCore.Components.ComponentBase.CallOnParametersSetAsync()
   at Microsoft.AspNetCore.Components.ComponentBase.SetParametersAsync(ParameterView parameters)
   at Radzen.RadzenComponent.<>n__0(ParameterView parameters)
   at Radzen.RadzenComponent.SetParametersAsync(ParameterView parameters)
   at Radzen.DropDownBase`1.SetParametersAsync(ParameterView parameters)
   at Radzen.Blazor.RadzenDropDown`1.SetParametersAsync(ParameterView parameters)
warn: Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer[100]
      Unhandled exception rendering component: Cannot access a disposed object.
System.ObjectDisposedException: Cannot access a disposed object.
   at Microsoft.AspNetCore.Components.RenderTree.ArrayBuilder`1.ThrowObjectDisposedException()
   at Microsoft.AspNetCore.Components.RenderTree.ArrayBuilder`1.GrowBuffer(Int32 desiredCapacity)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendStepOut(DiffContext& diffContext)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForFramesWithSameSequence(DiffContext& diffContext, Int32 oldFrameIndex, Int32 newFrameIndex)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.ComputeDiff(Renderer renderer, RenderBatchBuilder batchBuilder, Int32 componentId, ArrayRange`1 oldTree, ArrayRange`1 newTree)
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry renderQueueEntry)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()
fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
      Unhandled exception in circuit 'jNxGKLA069-ja4BoOanzbQpo0PByd9GfKpdzLzcA-_0'.
System.ObjectDisposedException: Cannot access a disposed object.
   at Microsoft.AspNetCore.Components.RenderTree.ArrayBuilder`1.ThrowObjectDisposedException()
   at Microsoft.AspNetCore.Components.RenderTree.ArrayBuilder`1.GrowBuffer(Int32 desiredCapacity)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendStepOut(DiffContext& diffContext)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForFramesWithSameSequence(DiffContext& diffContext, Int32 oldFrameIndex, Int32 newFrameIndex)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.ComputeDiff(Renderer renderer, RenderBatchBuilder batchBuilder, Int32 componentId, ArrayRange`1 oldTree, ArrayRange`1 newTree)
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry renderQueueEntry)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()

korchev · December 17, 2020, 5:32pm

You can try making the RoleList property IList. IEnumerable does not support adding and removing items. Check how this is done in our demo (DropDown with multiple selection).

panthernet · December 18, 2020, 11:03am

Thanks, but the provided example also has IEnumerable. IEnumerable<string> multipleValues. If I change it to IList as suggested I get an error on value select.

warn: Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer[100]
      Unhandled exception rendering component: Unable to cast object of type 'System.Linq.EnumerableQuery`1[System.String]' to type 'System.Collections.Generic.IList`1[System.String]'.
System.InvalidCastException: Unable to cast object of type 'System.Linq.EnumerableQuery`1[System.String]' to type 'System.Collections.Generic.IList`1[System.String]'.
   at Radzen.DropDownBase`1.SelectItem(Object item, Boolean raiseChange)
   at Radzen.Blazor.RadzenDropDown`1.OnSelectItem(Object item, Boolean isFromKey)
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)
fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
      Unhandled exception in circuit '4AdO892EyfFeE9ShMo4_1HPUXLlAd2jMcQo-f8Nm1cA'.
System.InvalidCastException: Unable to cast object of type 'System.Linq.EnumerableQuery`1[System.String]' to type 'System.Collections.Generic.IList`1[System.String]'.
   at Radzen.DropDownBase`1.SelectItem(Object item, Boolean raiseChange)
   at Radzen.Blazor.RadzenDropDown`1.OnSelectItem(Object item, Boolean isFromKey)
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)

korchev · December 18, 2020, 11:16am

We would need a reproduction in order to troubleshoot. You can try reproducing this issue with our online demo.

panthernet · December 18, 2020, 11:42am

Thanks for pointing, I solved it. Was getting _authRolesList as IEnumerable due to the LINQ query, added ToList() and it finally worked!

panthernet · December 18, 2020, 11:47am

But I assume it only works if _authRolesList items represents a class with properties and I have to set TextProperty="Name" ValueProperty="Name". Is it possible to bind to a simple string list? Had no luck with it yet.