I am trying to perform the following in a Blazor app. Default value = DateTime.Now. When a user enters a MMddyy or  MMddyyyy I want to automatically format  the date to MM/dd/yyyy. But I'm having an issue where the control automatically formats back to the default date value. Below is my layout for the DatePicker. I've tried different variations based on the demos Telerik provides but no luck. Hope someone can help. Thanks!

I'm getting the following error:

Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer[100]
      Unhandled exception rendering component: Object reference not set to an instance of an object.
      System.NullReferenceException: Object reference not set to an instance of an object.
         at Telerik.Blazor.Components.TelerikFileManager`1.ConvertToFileEntry(Object dataItem)

After I click the create folder button in the TelerikFileManager.  I've confirmed that it does reach the OnModelInit() method which does not return null, but never reaches the OnCreate() method.  Any ideas what might be causing this?

I have 2 questions on how to do something with the grid component.

Setup

Here are the options I have set for the grid component.

        <TelerikGrid @ref="Grid"
                        Data="Entries"
                        TItem="ProductEntryModel"
                        Class="font-size mb-1"
                        Sortable="true"
                        SortMode="@Telerik.Blazor.SortMode.Multiple"
                        FilterMode="@GridFilterMode.FilterMenu"
                        FilterMenuType="@FilterMenuType.CheckBoxList"
                        ScrollMode="@GridScrollMode.Virtual"
                        SelectionMode="@GridSelectionMode.Single"
                        Height="570px"
                        Width="100%"
                        RowHeight="40"
                        PageSize="@PageSize"
                        EditMode="@GridEditMode.Incell"
                        EnableLoaderContainer="@IsLoading"
                        @bind-SelectedItems="SelectedItems"                        
                        OnEdit="OnEditEventHandler"
                        OnUpdate="OnUpdateEventHandler"
                        Navigable="true"
                        Size="sm">

For Context the first cell is a TemplateColumn with a TelerikCombobox Component in it. 

On Load

It loads all the entries for the day selected. 

It adds a new line automatically at the bottom for adding more. But if the rows are longer than the height the new row will not fully show its whole height and I want it to start in edit of the first cell. The image shows that it is selected but not in edit.

This image is right after load. You can see the row is selected but not in edit and half off-screen. If the rows are further than the height it will not bring it into view either.

I would like it to start in view and the first cell in edit, how to accomplish that?

In Edit

This method below allows the user to keep adding rows to the grid after the PO NU... field loses focus. It works great as long as the grids next row is not out of view. Once it is out of view it will add the line, select it, and bring it to view, but the first cell is now out of edit and the user has to click in to the cell to start entry.  

Similar to above, how do I set the focus in the first cell?  Some of this code is different attempts to get it to work. 

    private async Task AddNewRecord(ProductEntryModel? entry = null)
    {
        if (Entries.Any(x => x.ProductId == 0)) return;
        var newLine = new ProductEntryModel
        {
            EntryDate = EntryDate,
            PoNumber = entry != null ? entry.PoNumber : "", // Carry down
            Sublet = entry != null && !string.IsNullOrWhiteSpace(entry.PoNumber) ? entry.Sublet : "", // Carry down            
        };
        Entries.Add(newLine); // Add A new line
        PageSize = Entries.Count > 15 ? Entries.Count : 15; // increase page size
        SelectedItems = new List<ProductEntryModel>() {newLine};  // Select new line
        await Task.Delay(100); // Wait for the grid to update - Doesn't help select the next entry
        await ProjectCombobox.FocusAsync();  // New Attempt and doesn't work
        //Grid.Rebind();

    }

Is there a way to open a dialog/window next to the button that opened it?

<GridColumns>
@foreach (DataRow column in gridColumnData.Rows )
{
<GridColumn Field="@nameof(Person.Age)" Title="@column["columnname"].ToString()" />
}
</GridColumns>

how can i make Field properties also dynamic without creating object model
when i display values without creating model i cant use filter mode it throws unhandled exception?

I'm in need for an OnRendered event (or similar) for a TelerikWindow component. Actually, it would be nice to have for all Telerik blazor components. I this particular case I need to know when a specific <div> is avaible to the browser DOM so that I can call some javascript interop on it. In this case I need to show I leaflet map in the modal window.

I solved it for now, using a javascript timeout of 0.1 second, but that is bad coding.

When scrolling up in a virtual grid, the rows "above" seems to not be kept or loaded like when scrolling down, and it takes a while before they gets "loaded" and shown. This behaviour is not very user friendly and should be corrected. I can accept a certain time of delay when doing large scrolls using the scrollbar, but not when doing a scroll-wheen or page-up scroll.

Unless I missed something in the grid properties? I got the PageSize set.

How to set in code the first row of the grid selected?

grdRptCallDetails_SelectedItems = RptResults[0].ToList();

Wont work. So How do I set that to the first row in the grid?

I am using treelist to display an hierarchical dataset that is read from an API using web calls.

I have encounbtered a problem where my source data contained many root items (which was an actual programming error), but by this surfaced a problem that you have to read ALL roots (or all children of an item) in order to make paging work correctly.

As in some cases I may have up to 10K "child" items (whichs unfortunately landed in my root due to the error), I would expect treeview and treelist to handle this without actually having to transfer 10K objects from my API call.

For this, a similar solution like the one used for the grid "OnRead" event would be a good solution as this could tell the treeview how many (root or direct child) objects there actually are  and provide the offset to start reading with and how many objects to return.

You could even throw in filtering and sorting for all I care and recycle the DataRequest class for this.

This in turn should help getting the "paging" right for the treelist/treeview.

Regards - Hans