Index.razor

@page "/"
@using AutoMapper
@using InstantFeedback.Models;
@using Microsoft.EntityFrameworkCore
@using DevExpress.Data.Linq
@inject IDbContextFactory<NorthwindContext> NorthwindContextFactory
@implements IDisposable

<DxGrid Data="InstantFeedbackSource"
        EditModelSaving="OnEditModelSaving"
        DataItemDeleting="OnDataItemDeleting"
        KeyFieldName="OrderId">
    <Columns>
        <DxGridCommandColumn />
        <DxGridDataColumn FieldName="ShipName" />
        <DxGridDataColumn FieldName="ShipCity" />
        <DxGridDataColumn FieldName="ShipCountry" />
        <DxGridDataColumn FieldName="Freight" />
        <DxGridDataColumn FieldName="OrderDate" />
        <DxGridDataColumn FieldName="ShippedDate" />
    </Columns>
    <EditFormTemplate Context="editFormContext">
        <DxFormLayout>
            <DxFormLayoutItem Caption="Ship Name:">
                @editFormContext.GetEditor("ShipName")
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Ship City:">
                @editFormContext.GetEditor("ShipCity")
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Ship Country:">
                @editFormContext.GetEditor("ShipCountry")
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Freight:">
                @editFormContext.GetEditor("Freight")
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Order Date:">
                @editFormContext.GetEditor("OrderDate")
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Shipped Date:">
                @editFormContext.GetEditor("ShippedDate")
            </DxFormLayoutItem>
        </DxFormLayout>
    </EditFormTemplate>
</DxGrid>
@code {
    EntityInstantFeedbackSource InstantFeedbackSource { get; set; }
    NorthwindContext Northwind { get; set; }
    IMapper ProductMapper { get; set; }

    protected override void OnInitialized() {
        Northwind = NorthwindContextFactory.CreateDbContext();
        InstantFeedbackSource = new EntityInstantFeedbackSource(e => {
            e.KeyExpression = "OrderId";
            e.QueryableSource = Northwind.Orders;
        });
        var config = new MapperConfiguration(c => c.CreateMap<Order, Order>());
        ProductMapper = config.CreateMapper();
    }
    async Task OnEditModelSaving(GridEditModelSavingEventArgs e) {
        var editModel = (Order)e.EditModel;
        // Re-query a data item from the database.
        var dataItem = e.IsNew ? new Order() : Northwind.Orders.Find(editModel.OrderId);
        // Assign changes from the edit model to the data item.
        if (dataItem != null) {
            ProductMapper.Map<Order, Order>(editModel, dataItem);
            // Post changes to the database.
            if (e.IsNew)
                await Northwind.AddAsync(dataItem);
            await Northwind.SaveChangesAsync();
        }
    }

    async Task OnDataItemDeleting(GridDataItemDeletingEventArgs e) {
        // Re-query a data item from the database.
        var orderId = e.Grid.GetDataItemValue(e.DataItem, "OrderId");
        var dataItem = Northwind.Orders.Find(orderId);
        if (dataItem != null) {
            // Remove the data item from the database.
            Northwind.Remove(dataItem);
            await Northwind.SaveChangesAsync();
        }
    }

    public void Dispose() {
        InstantFeedbackSource?.Dispose();
        Northwind?.Dispose();
    }
}