Hello,

im trying to render a treview but its not showing any item, im also print the results of my query on a table using a for loop and it shows the results ok , but the trevieww its not loading any data. Attached my code :

I am using the Telerik UI for Blazor 2.13. The export excel does not work with it. I am using the exact code snippet from docs as below on my test page:

@* You can sort, group, filter, page the grid, resize and reodrder its columns, and you can click the
    Export button to save the current data *@
@page "/test"
@using Telerik.Blazor.Components

<TelerikGrid Data="@GridData" Pageable="true" Sortable="true" Resizable="true" Reorderable="true"
              Groupable="true">

    <GridToolBar>
        <GridCommandButton Command="ExcelExport">Export to Excel</GridCommandButton>
        <label><TelerikCheckBox @bind-Value="@ExportAllPages" />Export All Pages</label>
    </GridToolBar>

    <GridExport>
        <GridExcelExport FileName="telerik-grid-export" AllPages="@ExportAllPages" />
    </GridExport>

    <GridColumns>
        <GridColumn Field="@nameof(SampleData.ProductId)" Title="ID" Width="100px" />
        <GridColumn Field="@nameof(SampleData.ProductName)" Title="Product Name" Width="300px" />
        <GridColumn Field="@nameof(SampleData.UnitsInStock)" Title="In stock" Width="100px" />
        <GridColumn Field="@nameof(SampleData.Price)" Title="Unit Price" Width="200px" />
        <GridColumn Field="@nameof(SampleData.Discontinued)" Title="Discontinued" Width="100px" />
        <GridColumn Field="@nameof(SampleData.FirstReleaseDate)" Title="Release Date" Width="300px" />
    </GridColumns>
</TelerikGrid>

@code {
    List<SampleData> GridData { get; set; }
    bool ExportAllPages { get; set; }

    protected override void OnInitialized()
    {
        GridData = Enumerable.Range(1, 100).Select(x => new SampleData
        {
            ProductId = x,
            ProductName = $"Product {x}",
            UnitsInStock = x * 2,
            Price = 3.14159m * x,
            Discontinued = x % 4 == 0,
            FirstReleaseDate = DateTime.Now.AddDays(-x)
        }).ToList();
    }

    public class SampleData
    {
        public int ProductId { get; set; }
        public string ProductName { get; set; }
        public int UnitsInStock { get; set; }
        public decimal Price { get; set; }
        public bool Discontinued { get; set; }
        public DateTime FirstReleaseDate { get; set; }
    }
}

Whenever I click on the export button. It simply does not respond. I do see lot of http requests though :

Please let me know if you need anymore details.

Dear team,

we use a BlazoredTypeahead control inside a TelerikWindow and have this problem.

When you open the result dropdown of BlazoredTypeahead and click on the scrollbar in the result dropdown, the result dropdown is closed suddenly.

This only happens when a BlazoredTypeahead control is inside a TelerikWindow. If I remove the Telerik Window everything works as expected.

Attached is a running example, which demonstrates the issue. In the example just click on the "New" button in the grid, this will open the TelerikWindow, which contains the BlazoredTypeahead control.

Thanks for your help.

With a pageable grid after scrolling down the first page and then paging, the next page should be scrolled to the top - but it is not.

Is there a way to scroll up by code until this is fixed ???

Submitted on customer behalf:

This line of code is taken directly out of your https://demos.telerik.com/blazor-ui/grid/editing-inline

What kind of magic updates the actual database?

privatevoidUpdateItem(GridCommandEventArgs args)

{

var argsItem = args.ItemasProductBindingModel;

var index =GridData.FindIndex(i => i.ProductId== argsItem.ProductId);

if(index !=-1)

{

GridData[index]= argsItem;

}

}"

Grid OnRead .Clear() Issue

With the following component:

@page "/counter"
@using System.Collections.ObjectModel
General grid with its most common features
<TelerikGrid Data="@MyData" Pageable="true" @bind-Page="page" PageSize="5" TotalCount="30" OnRead="@ReadItems" >
    <GridColumns>
        <GridColumn Field="@(nameof(SampleData.Id))" Width="120px" />
        <GridColumn Field="@(nameof(SampleData.Name))" Title="Employee Name" Groupable="false" />
        <GridColumn Field="@(nameof(SampleData.Team))" Title="Team" />
        <GridColumn Field="@(nameof(SampleData.HireDate))" Title="Hire Date" />
    </GridColumns>
</TelerikGrid>

@code {
    public List<SampleData> MyData { get; set; } = new List<SampleData>();
    //public ObservableCollection<SampleData> MyData { get; set; } = new ObservableCollection<SampleData>();
    private int page = 1;

    private void ReadItems(GridReadEventArgs args)
    {
        //MyData = new List<SampleData>();  //OK!
        //MyData = new ObservableCollection<SampleData>(); //OK!
        MyData.Clear();  //List: No update. ObservableCollection: System.StackOverflowException!
        Populate();
        StateHasChanged();
    }

    private void Populate()
    {
        foreach (var data in Enumerable.Range((page - 1) * 5, 5).Select(x => new SampleData
        {
            Id = x,
            Name = "name " + x,
            Team = "team " + x % 5,
            HireDate = DateTime.Now.AddDays(-x).Date
        }))
        {
            MyData.Add(data);
        }
    }

    public class SampleData
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Team { get; set; }
        public DateTime HireDate { get; set; }
    }
}

I see the issues in the comment fields.  Changing OnRead to async makes no difference.  

The workaround is to assign a new List or ObservableCollection instead of using .Clear()

ADMIN EDIT: The issue stems from the data operations in the business logic, and it is not a bug in the component and it does not relate to WebAPI usage.

Hi there,

as a follow-up of https://feedback.telerik.com/blazor/1461176-set-specific-position-in-virtual-scrolling-mode we have implemented the suggested skip handling. But there seems an issue when the data is fetched asynchronously, specifically from an Web API.

After hours of debugging and analyzing i have narrowed it down to the following simple Blazor app showcasing the bug:

https://github.com/ViRuSTriNiTy/blazor-app-telerik-grid-skip-bug

Please clone the repo, start the application and follow the steps displayed above the grid to reproduce the bug.

The second skip followed immediatelly after the first one originates from the Telerik assembly hence i cannot investigate it further (no source code).

What are your thoughts? Is it a bug?

So lonG

Daniel

row height set in grid definition must apply to all rows in the grid for row virtualization as of now. 

in real business case there might be complex content in each row that can't reinforce this - but if each row report its own height, grid still can visualize the load, and it will be much more flexible. 

It would be great if the controls supported arbitrary attributes. Similar to how it is done in the native form editing controls in Blazor framework.

ASP.NET Core Blazor forms and validation

"All of the input components, including EditForm, support arbitrary attributes. Any attribute that doesn't match a component parameter is added to the rendered HTML element."

Looking through the examples I can't find one with SelectionMode="GridSelectionMode.Multiple" and using a RowTemplate.

ADMIN EDIT: This is not a bug in the component, an example of how this can be implemented by the app is available in the comments.

I'm not sure what I should be binding my checkbox to so it accurately reflects selection state.

From the RowTemplate Example adding SelectionMode:

<TelerikGrid Data=@GridData
             @bind-SelectedItems="@SelectedItems"             
             SelectionMode="GridSelectionMode.Multiple"
             Height="@Height">
    <RowTemplate Context="product">
         @*Trying to inspect what is generated in the examples I came up with this, but not sure what to bind to checked*@
               <td role="gridcell" colspan=0 data-col-index="0">
                    <span>
                        <input class="k-checkbox k-grid-checkbox telerik-blazor" type="checkbox" />
                    </span>
                </td>
         <td>
            <img class="rounded-circle" src="@($"images/{product.ProductId}.jpg")" alt="Alternate Text" />
            @product.ProductName
        </td>
        <td>
            @(String.Format("{0:C2}", product.UnitPrice))
        </td>
    </RowTemplate>
    <GridColumns>
        <GridColumn Field=@nameof(Product.ProductName) Title="Product Name" />
        <GridColumn Field=@nameof(Product.UnitPrice) Title="Unit Price" />
    </GridColumns>
</TelerikGrid>

@GridEditMode.Incell mode does not update automatically on row change when an editortemplate is used, as below

            <GridColumn Field=@nameof(ProjectRankingInfo.Ranking.Option2) Title="@Option2Title" Width="120px" Filterable="false">
                <EditorTemplate>
                    @{
                        currentItem = context as ProjectRankingInfo.Ranking;
                        <TelerikNumericTextBox Max="10" Min="0" Step="1" @bind-Value=@currentItem.Option2 />
                    }
                </EditorTemplate>
            </GridColumn>

one must click the update button for the update to occur,

Incell works fine and updates on row change for simple grid columns

ADMIN EDIT: SOLUTION: Read the details in the following article: https://docs.telerik.com/blazor-ui/components/grid/editing/incell#notes

ADMIN EDIT: this thread is rather long and I am adding the workaround offered by René here:

Admin edit: While this cannot become a built-in feature, you may find useful the following example: https://github.com/telerik/blazor-ui/tree/master/common/grpc-example

Hello Team;

As .Net Core 3 offers gRPC support, I'm suggesting that the Blazor Team, look into some of the components that could automatically talk to backend gRPC services to get data, i.e. Auto Complete or DropDown box.

This way it could simplify different ways of providing datasource to some of these data oriented components.

Hope this suggestion helps!
..Ben

TelerikGird with virtual scrolling was working in version 2.7, but after upgrading to 2.10, it is only showing placeholders.

When scrolling, it shows the values for a split second, but then those get replaced by the placeholders.

@page "/test"

<TelerikGrid Data=@GridData
             SelectionMode="GridSelectionMode.Single"
             ScrollMode="GridScrollMode.Virtual"
             Height="300px" RowHeight="20">
    <GridColumns>
        <GridColumn Field=@nameof(Employee.Name) />
        <GridColumn Field=@nameof(Employee.Team) Title="Team" />
    </GridColumns>
</TelerikGrid>

@code {
    public List<Employee> GridData { get; set; }

    protected override void OnInitialized()
    {
        GridData = new List<Employee>();
        for (int i = 0; i < 15; i++)
        {
            GridData.Add(new Employee()
            {
                EmployeeId = i,
                Name = "Employee " + i.ToString(),
                Team = "Team " + i % 3
            });
        }
    }

    public class Employee
    {
        public int EmployeeId { get; set; }
        public string Name { get; set; }
        public string Team { get; set; }
    }
}

I'd like to request a native Blazor Image Component that allows to provide different parameters to control the image.

This could also help to connect it to the upload component, for user to see the image while still in browser and make some changes, i.e resizing, cropping, Black/White, before sending it to server to be stored.

Thanks!
..Ben

The CSS classes used by Blazor UI are not documented. (I haven't looked outside the Blazor area, so maybe it's somewhere else in the docs? My team has no need for other Telerik products.) On a similar note, the Themes page in the documentation explains how to reference alternate themes like Bootstrap, but it doesn't explain how to actually use the classes, or how it integrates with the real Bootstrap CSS, which have many various useful, well-known utilities like margin and padding settings, which don't seem to be part of the Telerik theme support. (I'm an architect at a very large corporation, we do have one of those includes-everything DevCraft licenses, I just can't log in with that account.)

I'm making a wrapper on top of TelerikDatePicker and this is how my component is working

<TelerikDatePicker T="TDate"
                   Value="@_value"
                   ValueChanged="@ValueChanged"
                   ValueExpression="@ValueExpression"
                   Enabled="@Enabled"
                   Class="@ClassMapper.AsString()"
                   Format="@Format" />

@code {

    // ... the other properties

    [Parameter]
    public virtual string Format { get; set; }

}

But here is the problem. This component will give me the error

Error: System.AggregateException: One or more errors occurred. (Value cannot be null. (Parameter 'input'))
 ---> System.ArgumentNullException: Value cannot be null. (Parameter 'input')
   at System.Text.RegularExpressions.Regex.Replace(String input, String replacement)
   at System.Text.RegularExpressions.Regex.Replace(String input, String pattern, String replacement)
   at Telerik.Blazor.Common.DateHelpers.FormatHelper.ExpandFormat(String format)
   at Telerik.Blazor.Common.DateHelpers.FormatHelper.ConvertToKendoIntl(String format)
   at Telerik.Blazor.Components.TelerikDateInputBase`1.GetDateInputOptions()
   at Telerik.Blazor.Components.TelerikDateInputBase`1.OnAfterRenderAsync(Boolean firstRender)

So another solution would be set it to string.Empty, but than it will have a different result when I don't pass the Format property.

Here are the cases:

    [Parameter]
    public virtual string Format { get; set; } // gives the error

    [Parameter]
    public virtual string Format { get; set; } = ""; // doesn't give the default result

I had to make a walkaround to not pass Format to the component for it to work

@if (!string.IsNullOrEmpty(Format))
{
    <TelerikDatePicker T="TDate"
                       Value="@_value"
                       ValueChanged="@ValueChanged"
                       ValueExpression="@ValueExpression"
                       Enabled="@Enabled"
                       Class="@ClassMapper.AsString()"
                       Format="@Format" />
}
else
{
    <TelerikDatePicker T="TDate"
                       Value="@_value"
                       ValueChanged="@ValueChanged"
                       ValueExpression="@ValueExpression"
                       Enabled="@Enabled"
                       Class="@ClassMapper.AsString()" />
}

What should I set as a default value to my wrapper's Format property so it doesn't give me the error and also get's the default value of Format?

Please don't say that I should keep the @if (!string.IsNullOrEmpty(Format)), it's so bad and I don't want to use telerik and still have to make walkarounds.