I know this is a common problem, but none of the solutions resolved my issue. All explanations seemed logical at first but after implementing them it did absolutely nothing and I'm kinda at a loss here.
Nothing I do to lets me update my UI component and just display some error messages which come from data annotation attributes. I am manually checking my data model for validity and in the case of being invalid I'm updating a list of error messages which in turn should be displayed inside my UI.
This is my component:
@using Syncfusion.Blazor.Grids@using Syncfusion.Blazor.Buttons@using Syncfusion.Blazor.Popups@using Syncfusion.Blazor.DropDowns@using Syncfusion.Blazor.Calendars@using Syncfusion.Blazor.Inputs@using Syncfusion.Blazor.SplitButtons@using Syncfusion.Blazor.Data@using Blazored.Toast.Services@using Microsoft.Data.SqlClient@using System.Text@using Syncfusion.Blazor.Spinner@using System.ComponentModel.DataAnnotations;<SfGrid ID="Grid" Query="@query" HtmlAttributes="htmlAttributes" DataSource="@transactions" @ref="Grid" AllowPaging="true" AllowFiltering="true" AllowExcelExport="true" AllowSorting="true" Toolbar="@(new List<string>() {"Edit", "ExcelExport" })"><GridFilterSettings Type="Syncfusion.Blazor.Grids.FilterType.FilterBar"></GridFilterSettings><GridPageSettings PageCount="5" PageSize="20" PageSizes="@(new string[] { "5", "10", "20", "40", "50", "All" })"></GridPageSettings><GridSelectionSettings Type="Syncfusion.Blazor.Grids.SelectionType.Multiple"></GridSelectionSettings><GridEvents OnActionBegin="ActionBeginHandler" OnToolbarClick="ToolbarClick" TValue="unknownasgdata"></GridEvents><GridEditSettings AllowAdding="true" AllowEditing="true" AllowDeleting="true" Mode="EditMode.Dialog" Dialog="DialogParams" ShowConfirmDialog="true"><Validator><DataAnnotationsValidator></DataAnnotationsValidator></Validator><Template> @{ var unknownItem = (context as unknownasgdata);<div> @if (validationResults.Any()) {<div class="validation-summary"> @foreach (var validationResult in validationResults) {<div>@validationResult.ErrorMessage</div> }</div> }<br/><div class="form-row"><div class="form-group col-md-6"><label><b>Bezeichnung</b></label><br /> @(unknownItem.description)</div></div><div class="form-row"><div class="form-group col-md-6"><label><b>Betriebsstätte</b></label><br /> @(unknownItem.house)</div></div><div class="form-row"><div class="form-group col-md-6"><label><b>Leistungsnummer</b></label><br /> @(unknownItem.leinr)</div></div><div class="form-row"><div class="form-group col-md-6"><label><b>Preis</b></label><br /><SfNumericTextBox @bind-Value="@(unknownItem.articleprice)" ></SfNumericTextBox></div></div><br/><div class="form-row"><div class="form-group col-md-6"><label><b>Mahlzeitart</b></label><br/><SfDropDownList TValue="string" TItem="string" DataSource="@(new List<string> { "Frühstück", "Mittagessen", "Abendessen" })" @bind-Value="@(unknownItem.selectedMahlzeit)"></SfDropDownList></div> </div></div> }</Template><FooterTemplate><SfButton OnClick="@SubmitForm" IsPrimary="true">Speichern</SfButton><SfButton OnClick="Cancel">Abbrechen</SfButton></FooterTemplate></GridEditSettings><GridColumns><GridColumn Field=@nameof(unknownasgdata.description) HeaderText="Beschreibung"></GridColumn><GridColumn Field=@nameof(unknownasgdata.leinr) HeaderText="Lst.Nummer" Width="150"></GridColumn><GridColumn Field=@nameof(unknownasgdata.house) HeaderText="Betriebsstätte" Width="100"></GridColumn></GridColumns></SfGrid>@code{ private async Task<bool> ValidateModel() { validationResults.Clear(); bool isValid = Validator.TryValidateObject(unknownItem, validationContext, validationResults, true); Task.Delay(3000); return isValid; } private async Task SubmitForm() { if (await ValidateModel()) { // Proceed with database updates // Your database update logic here } else { // Handle validation failures // Show validation messages validationResults = new List<ValidationResult>(validationResults); await Task.Delay(3000); await InvokeAsync(() => { StateHasChanged(); // Ensure the UI is updated to reflect validation errors }); await Task.Yield(); } }}There is, of course, a bit of code missing here and there that is important to the class but you can just assume that the basics like initializing variables are working. What I am trying to do is just Submitting my Form and doing a Validation beforehand. ValidateModel() populates the List validationResults which I want to display in my razor component. In theory, shouldn't the component re render as soon as I update the List, since I am checking for elements inside my razor components? I tried calling StateHasChanged multiple times sync and async and using Task.Delay whenever I can but nothing works and nothing lets me update the UI.