<TelerikButton OnClick="@ToggleStep">Toggle attachments step visibility</TelerikButton>

@if (WizardVisible)
{
    <TelerikWizard @bind-Value="@CurrStepIndex">
        <WizardSteps>
            <WizardStep Label="Personal Details" Icon="SvgIcon.User">
                <Content>
                    content here
                </Content>
            </WizardStep>

            @if (AttachmentsStepVisible)
            {
                <WizardStep Label="Attachments" Icon="SvgIcon.Paperclip">
                    <Content>
                        conditional content here
                    </Content>
                </WizardStep>
            }

            <WizardStep Label="Confirmation" Icon="SvgIcon.Check">
                <Content>
                    other content here
                </Content>
            </WizardStep>
        </WizardSteps>
    </TelerikWizard>
}


@code {
    private bool AttachmentsStepVisible { get; set; }
    private bool WizardVisible { get; set; } = true;

    private int CurrStepIndex { get; set; }

    private async void ToggleStep()
    {
        //dispose the Wizard
        WizardVisible = false;

        // defence against hiding the step when it is the last step, which would cause an exception
        if (AttachmentsStepVisible && CurrStepIndex == 2)
        {
            CurrStepIndex = 1;
        }

        //the actual visibility toggle
        AttachmentsStepVisible = !AttachmentsStepVisible;

        //allow some time for the disposal and toggling the step visibility prior to re-initialization
        await Task.Delay(10);

        //re-initialize the Wizard
        WizardVisible = true;

        StateHasChanged();
    }
}

@using System.Dynamic
@using Telerik.DataSource
@using Telerik.DataSource.Extensions

<TelerikGrid OnRead="@OnGridRead"
             TItem="@ExpandoObject"
             Pageable="true"
             Sortable="true"
             FilterMode="@GridFilterMode.FilterMenu"
             FilterMenuType="@FilterMenuType.CheckBoxList"
             Height="400px">
    <GridToolBarTemplate>
        <GridSearchBox />
    </GridToolBarTemplate>
    <GridColumns>
        @{
            if (GridData != null && GridData.Any())
            {
                <GridColumn Field="PropertyInt" FieldType="@GridPropertyTypes["PropertyInt"]" />
                <GridColumn Field="PropertyString" FieldType="@GridPropertyTypes["PropertyString"]" />
                <GridColumn Field="PropertyGroup" FieldType="@GridPropertyTypes["PropertyString"]" />
                <GridColumn Field="PropertyDate" FieldType="@GridPropertyTypes["PropertyDate"]" />
                <GridColumn Field="PropertyBool" FieldType="@GridPropertyTypes["PropertyBool"]" />
            }
        }
    </GridColumns>
</TelerikGrid>

@code {
    private List<ExpandoObject> GridData { get; set; } = new List<ExpandoObject>();

    private Dictionary<string, Type> GridPropertyTypes { get; set; } = new Dictionary<string, Type>() {
        { "Id", typeof(int) },
        { "PropertyInt", typeof(int) },
        { "PropertyString", typeof(string) },
        { "PropertyGroup", typeof(string) },
        { "PropertyDate", typeof(DateTime) },
        { "PropertyBool", typeof(bool) }
    };

    private async Task OnGridRead(GridReadEventArgs args)
    {
        args.Request.Filters.OfType<CompositeFilterDescriptor>()
        .Each(x =>
        {
            x.FilterDescriptors.OfType<FilterDescriptor>()
                .Each(y => y.MemberType = GridPropertyTypes[y.Member]);
        });

        var result = GridData.ToDataSourceResult(args.Request);

        args.Data = result.Data;
        args.Total = result.Total;
        args.AggregateResults = result.AggregateResults;
    }

    protected override void OnInitialized()
    {
        for (int i = 1; i <= 18; i++)
        {
            dynamic expando = new ExpandoObject();

            expando.Id = i;
            expando.PropertyGroup = $"Group {(i % 3 + 1)}";
            expando.PropertyInt = i;
            expando.PropertyString = $"String {(char)(64 + i)}{(char)(64 + i)}";
            expando.PropertyDate = DateTime.Now.AddMonths(-i);
            expando.PropertyBool = i % 2 != 0;

            GridData.Add(expando);
        }
    }
}

DropDownTreeValue1: @DropDownTreeValue1
<br />
DropDownTreeValue2: @DropDownTreeValue2

<br />

Bug:
<TelerikDropDownTree Data="@DropDownTreeData"
                     @bind-Value="@DropDownTreeValue1"
                     @bind-ExpandedItems="@DropDownTreeExpandedItems"
                     Width="300px">
</TelerikDropDownTree>

Workaround:
<TelerikDropDownTree Data="@DropDownTreeData"
                     @bind-Value="@DropDownTreeValue2"
                     @bind-ExpandedItems="@DropDownTreeExpandedItems"
                     Width="300px">
</TelerikDropDownTree>

@* Render DropDownTree after setting Data *@
@if (DropDownTreeData is not null)
{
    <span>Workaround:</span>
    <TelerikDropDownTree Data="@DropDownTreeData"
                        @bind-Value="@DropDownTreeValue1"
                        @bind-ExpandedItems="@DropDownTreeExpandedItems"
                        Width="300px">
    </TelerikDropDownTree>
}

@code {
    private List<TreeItem>? DropDownTreeData { get; set; }

    private int DropDownTreeValue1 { get; set; }
    private int DropDownTreeValue2 { get; set; }

    private IEnumerable<object> DropDownTreeExpandedItems { get; set; } = new List<TreeItem>();

    protected override async Task OnInitializedAsync()
    {
        DropDownTreeValue1 = 3;
        await Task.Delay(1000);
        DropDownTreeData = LoadFlatData();

        // Set DropDownTree Value after setting Data
        DropDownTreeValue2 = 3;

        DropDownTreeExpandedItems = DropDownTreeData.Where(x => x.ParentId is null && x.HasChildren);
    }

    private int TreeLevels { get; set; } = 3;
    private int RootItems { get; set; } = 2;
    private int ItemsPerLevel { get; set; } = 2;
    private int IdCounter { get; set; }

    private List<TreeItem> LoadFlatData()
    {
        List<TreeItem> items = new List<TreeItem>();

        PopulateChildren(items, null, 1);

        return items;
    }

    private void PopulateChildren(List<TreeItem> items, int? parentId, int level)
    {
        var itemCount = level == 1 ? RootItems : ItemsPerLevel;
        for (int i = 1; i <= itemCount; i++)
        {
            var itemId = ++IdCounter;
            items.Add(new TreeItem()
            {
                Id = itemId,
                ParentId = parentId,
                HasChildren = level < TreeLevels,
                Text = $"Level {level} Item {i} Id {itemId}",
                Value = itemId
            });

            if (level < TreeLevels)
            {
                PopulateChildren(items, itemId, level + 1);
            }
        }
    }

    public class TreeItem
    {
        public int Id { get; set; }
        public int? ParentId { get; set; }
        public bool HasChildren { get; set; }
        public string Text { get; set; } = string.Empty;
        public int Value { get; set; }
    }
}

Selected value: @myDdlData.ToList().Where(x => x.Id == selectedValueId).FirstOrDefault()?.MyValueField.ToString("MM/dd/yyyy HH:mm:ss.fff")
<br />

<TelerikDropDownList Data="@myDdlData" 
                     TextField="MyTextField" 
                     ValueField="Id" 
                     @bind-Value="selectedValueId">
</TelerikDropDownList>

@code {
    public class MyDdlModel
    {
        public int Id { get; set; }
        public DateTime MyValueField { get; set; }
        public string MyTextField => MyValueField.ToString("MM/dd/yyyy HH:mm:ss.fff"); // Display formatted DateTime
    }

    private int selectedValueId { get; set; } = 1;

    private IEnumerable<MyDdlModel> myDdlData = GenerateRandomDateTimes(20);

    private static IEnumerable<MyDdlModel> GenerateRandomDateTimes(int count)
    {
        Random random = new Random();
        DateTime startDate = DateTime.Now;

        return Enumerable.Range(1, count)
            .Select(x => new MyDdlModel
            {
                Id = x, // Unique integer Id
                MyValueField = startDate.AddDays(x)
                    .AddMinutes(random.Next(0, 60))
                    .AddSeconds(random.Next(0, 60))
                    .AddMilliseconds(random.Next(0, 1000))
            }).ToList();
    }
}

@using System.ComponentModel.DataAnnotations
@using Telerik.DataSource
@using Telerik.DataSource.Extensions

<TelerikGrid @ref="@GridRef"
             OnRead="@OnGridRead"
             TItem="@Product"
             EditMode="@GridEditMode.Incell"
             OnCreate="@OnGridCreate"
             OnDelete="@OnGridDelete"
             OnUpdate="@OnGridUpdate"
             Height="600px">
    <GridToolBarTemplate>
        <GridCommandButton Command="Add">Add Item</GridCommandButton>
    </GridToolBarTemplate>
    <GridColumns>
        <GridColumn Field="@nameof(Product.Name)">
            <EditorTemplate>
                @{ var dataItem = (Product)context; }
                <span @onfocusout="@( async () => await OnGridCellFocusOut(nameof(Product.Name)) )">
                    <TelerikTextBox @bind-Value="@dataItem.Name" />
                </span>
            </EditorTemplate>
        </GridColumn>
        @* <GridColumn Field="@nameof(Product.Price)" DisplayFormat="{0:C2}" />
        <GridColumn Field="@nameof(Product.Quantity)" DisplayFormat="{0:N0}" />
        <GridColumn Field="@nameof(Product.ReleaseDate)" DisplayFormat="{0:d}" /> *@
        <GridColumn Field="@nameof(Product.Discontinued)" Width="120px">
            <EditorTemplate>
                @{ var dataItem = (Product)context; }
                <span @onfocusout="@( async () => await OnGridCellFocusOut(nameof(Product.Discontinued)) )">
                    <TelerikCheckBox @bind-Value="@dataItem.Discontinued" />
                </span>
            </EditorTemplate>
        </GridColumn>
        <GridCommandColumn Width="180px">
            <GridCommandButton Command="Delete">Delete</GridCommandButton>
        </GridCommandColumn>
    </GridColumns>
</TelerikGrid>

@code {
    private TelerikGrid<Product>? GridRef { get; set; }

    private ProductService GridProductService { get; set; } = new();

    private async Task OnGridCellFocusOut(string field)
    {
        await Task.Delay(100);

        if (GridRef is null)
        {
            return;
        }

        GridState<Product> gridState = GridRef.GetState();
        Product? editItem = gridState.EditItem as Product;

        if (editItem is null)
        {
            return;
        }

        GridCommandEventArgs args = new GridCommandEventArgs()
        {
             Field = field,
             Item = editItem
        };

        await OnGridUpdate(args);


        gridState.EditField = default;
        gridState.EditItem = default!;
        gridState.OriginalEditItem = default!;

        await GridRef.SetStateAsync(gridState);
    }

    private async Task OnGridCreate(GridCommandEventArgs args)
    {
        var createdItem = (Product)args.Item;

        await GridProductService.Create(createdItem);
    }

    private async Task OnGridDelete(GridCommandEventArgs args)
    {
        var deletedItem = (Product)args.Item;

        await GridProductService.Delete(deletedItem);
    }

    private async Task OnGridRead(GridReadEventArgs args)
    {
        DataSourceResult result = await GridProductService.Read(args.Request);

        args.Data = result.Data;
        args.Total = result.Total;
        args.AggregateResults = result.AggregateResults;
    }

    private async Task OnGridUpdate(GridCommandEventArgs args)
    {
        var updatedItem = (Product)args.Item;

        await GridProductService.Update(updatedItem);
    }

    public class Product
    {
        public int Id { get; set; }
        [Required]
        public string Name { get; set; } = string.Empty;
        public string Description { get; set; } = string.Empty;
        public decimal? Price { get; set; }
        public int Quantity { get; set; }
        [Required]
        public DateTime? ReleaseDate { get; set; }
        public bool Discontinued { get; set; }
    }

    #region Data Service

    public class ProductService
    {
        private List<Product> Items { get; set; } = new();

        private int LastId { get; set; }

        public async Task<int> Create(Product product)
        {
            await SimulateAsyncOperation();

            product.Id = ++LastId;

            Items.Insert(0, product);

            return LastId;
        }

        public async Task<bool> Delete(Product product)
        {
            await SimulateAsyncOperation();

            if (Items.Contains(product))
            {
                Items.Remove(product);

                return true;
            }

            return false;
        }

        public async Task<List<Product>> Read()
        {
            await SimulateAsyncOperation();

            return Items;
        }

        public async Task<DataSourceResult> Read(DataSourceRequest request)
        {
            return await Items.ToDataSourceResultAsync(request);
        }

        public async Task<bool> Update(Product product)
        {
            await SimulateAsyncOperation();

            int originalItemIndex = Items.FindIndex(x => x.Id == product.Id);

            if (originalItemIndex != -1)
            {
                Items[originalItemIndex] = product;
                return true;
            }

            return false;
        }

        private async Task SimulateAsyncOperation()
        {
            await Task.Delay(100);
        }

        public ProductService(int itemCount = 5)
        {
            Random rnd = Random.Shared;

            for (int i = 1; i <= itemCount; i++)
            {
                Items.Add(new Product()
                {
                    Id = ++LastId,
                    Name = $"Product {LastId}",
                    Description = $"Multi-line\ndescription {LastId}",
                    Price = LastId % 2 == 0 ? null : rnd.Next(0, 100) * 1.23m,
                    Quantity = LastId % 2 == 0 ? 0 : rnd.Next(0, 3000),
                    ReleaseDate = DateTime.Today.AddDays(-rnd.Next(365, 3650)),
                    Discontinued = LastId % 2 == 0
                });
            }
        }
    }

    #endregion Data Service
}