DataGrid LoadData No records problem

Radzen.Blazor Components
1

Hi,
I am using LoadData even though data retrieved from the database is not displayed on the grid.

Here is the grid:

<RadzenDataGrid @ref="_grid" AllowFiltering="true" AllowPaging="true" AllowSorting="true" Data="@_orders" TItem="ReportViewModel"
                            PagerHorizontalAlign="HorizontalAlign.Left" ShowPagingSummary="true" AllowColumnResize="true" 
                            AllowVirtualization="true" Style="width: calc(100vw - 120px);" ColumnWidth="170px" PageSize="5" LoadData="@LoadData" >

Here is the related code:

IEnumerable<ReportViewModel?> _orders;
    IEnumerable<Vendor?> _vendors = new List<Vendor?>();
    IEnumerable<Customer?> _customers;
    ClaimsPrincipal user;
    IEnumerable<ReportViewModel?> query;
    List<string> vendorNames;

    protected override async Task OnInitializedAsync()
    {
        user = (await _authenticationStateProvider.GetAuthenticationStateAsync()).User;

        if (!user.Identity.IsAuthenticated)
        {
            NavigationManager.NavigateTo("/Identity/Account/Login", false);
        }

        _vendors = await ViewAllVendorsUseCase.ExecuteAsync();
        _customers = await ViewAllCustomersUseCase.ExecuteAsync();
        vendorNames = _vendors.Select(c => c.Name).ToList();
        
    }

async Task LoadData(LoadDataArgs args)
    {
         _orders = await GetOrdersExportUseCase.ExecuteAsync(_vendorId, _status, _startDate, _endDate, _detailStatus, _customerId, user);

        IQueryable<ReportViewModel?> query = _orders.AsQueryable(); 
        
        if (!string.IsNullOrEmpty(args.Filter)){
        
            query = query.Where(args.Filter);
        }
        if (!string.IsNullOrEmpty(args.OrderBy)){
   
            query = query.OrderBy(args.OrderBy);
        }
        _orders = query.ToList();
        StateHasChanged();
    }

Here is the debug:

records
records1163×709 50.4 KB

Here is the screenshot:

No records
No records1337×648 13.5 KB

2

When using the LoadData event you need to set the Count attribute of RadzenDataGrid.

1 Like
3

Thank you @korchev.
There is something strange about the selection of dropdown that I can't understand. When I select vendors from the dropdown, the grid is not filtered. But when I unselect the list from the dropdown, the grid gets filtered.

<RadzenDataGridColumn TItem="ReportViewModel" Property="VendorName" Title="Vendor" 
                                          Type="typeof(IEnumerable<string>)" FilterValue="@selectedVendors" FilterOperator="FilterOperator.Contains" LogicalFilterOperator="LogicalFilterOperator.Or">
                    <FilterTemplate>
                            <RadzenDropDown Style="width:100%;" @bind-Value=@selectedVendors Placeholder="Select..."
                                            Change=@OnSelectedVendorsChange Data="@(vendorNames)" AllowClear="true" Multiple="true"/>
                    </FilterTemplate>
                    </RadzenDataGridColumn>

Everything seems OK, _orders get the filtered records but the grid is not filtered until the selected value is unselected from the dropdown.

filter
filter1335×648 57 KB

By the way, is it normal for the LoadData method to be called 3 times when the page is loading?

4

I am afraid I can't answer those questions without reproducing the problem first. If you have a subscription you can send us your project to info@radzen.com.

BTW I noticed there is a StateHasChanged call in the LoadData event which is not needed.

5

Thank you @korchev, filtering is not firing when selecting from the dropdown in my case, after selecting the value in the dropdown, I click on the grid somewhere, and it fires and the filter applies. I know it's hard to detect without the source code, but I'm asking in case you've come across it.