Reputation: 974
I have a simple problem with data binding. I'm not able to get the datagrid DeviceDataGrid
to visualise the entity information. The MainWindow.xaml
file is as follows:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:domain="clr-namespace:FxEditorDatabaseStructure.Core.Domain"
mc:Ignorable="d" x:Class="FxEditorDatabaseStructure.MainWindow"
Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded">
<Window.Resources>
<CollectionViewSource x:Key="DeviceViewSource" d:DesignSource="{d:DesignInstance {x:Type domain:Device}, CreateList=True}"/>
</Window.Resources>
<Grid DataContext="{StaticResource DeviceViewSource}">
<DataGrid x:Name="DeviceDataGrid" AutoGenerateColumns="False" EnableRowVirtualization="True" ItemsSource="{Binding}" Margin="0,64,0,0" RowDetailsVisibilityMode="VisibleWhenSelected">
<DataGrid.Columns>
<DataGridTextColumn x:Name="NameColumn" Binding="{Binding Name}" Header="Name" Width="250"/>
<DataGridTextColumn x:Name="SocketCountColumn" Binding="{Binding DeviceId}" Header="Id" Width="Auto"/>
<DataGridTextColumn x:Name="DescriptionColumn" Binding="{Binding Description}" Header="Description" Width="Auto"/>
<DataGridTextColumn x:Name="ProductTypeColumn" Binding="{Binding ProductType}" Header="Product Type" Width="*"/>
</DataGrid.Columns>
</DataGrid>
<Button Content="Add" HorizontalAlignment="Left" Margin="23,25,0,0" VerticalAlignment="Top" Width="75" RenderTransformOrigin="-0.143,-0.057" Click="AddDevice_Click"/>
</Grid>
</Window>
And trying to visualise the data within the entity on MainWindow. The database is correctly created and even the add button works. This I am able to see with Firefox SQLite Manager.
Here is the xaml.cs file which is "binding" the entity into the datagrid after eager loading entities into memory:
public partial class MainWindow : Window
{
private FxContext _context = new FxContext();
public MainWindow()
{
InitializeComponent();
_context.Database.Migrate();
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
_context.Devices.Add(new Device
{
ProductCode = "100",
Name = "LUX999",
Description = "Measurement device",
Supplier = "X",
Category = "Sensors",
ProductType = "Field device",
TimeCreated = DateTime.Now
});
_context.SaveChanges();
System.Windows.Data.CollectionViewSource deviceViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("DeviceViewSource")));
_context.Devices.Load();
_context.Sockets.Load();
_context.ProductTypes.Load();
deviceViewSource.Source = _context.Devices.GetLocal();
deviceViewSource.Source = _context.Categories.GetLocal();
deviceViewSource.Source = _context.ProductTypes.GetLocal();
}
protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
{
base.OnClosing(e);
_context.Dispose();
}
private void AddDevice_Click(object sender, RoutedEventArgs e)
{
_context.Devices.Add(
new Device
{
TimeCreated = DateTime.Now,
Name = "New Device at " + DateTime.Now.ToShortDateString()
});
_context.SaveChanges();
}
}
}
Because the EF7 (core) still lacks the implementation of local() I'm using an alternative extension method.
public static class Extensions
{
public static ObservableCollection<TEntity> GetLocal<TEntity>(this DbSet<TEntity> set)
where TEntity : class
{
var context = set.GetService<DbContext>();
var data = context.ChangeTracker.Entries<TEntity>().Select(e => e.Entity);
var collection = new ObservableCollection<TEntity>(data);
collection.CollectionChanged += (s, e) =>
{
if (e.NewItems != null)
{
context.AddRange(e.NewItems.Cast<TEntity>());
}
if (e.OldItems != null)
{
context.RemoveRange(e.OldItems.Cast<TEntity>());
}
};
return collection;
}
}
When I run the application the datagrid is not showing any values from the database in its list view. Somehow this line is not transferring the entity correctly deviceViewSource.Source = _context.Devices.GetLocal();
OR some binding procedure is wrong in the xaml-file?
Any ideas what I'm doing wrong?
Upvotes: 3
Views: 3958
Reputation: 27338
The problem is, that you set deviceViewSource.Source
to devices, then replaced with Categories, then with ProductTypes
deviceViewSource.Source = _context.Devices.GetLocal();
deviceViewSource.Source = _context.Categories.GetLocal();
deviceViewSource.Source = _context.ProductTypes.GetLocal();
at the and, you are databanding to ProductTypes... Remove the two bottom lines.
I believe that you dont need the GetLocal() method neither. Try this:
deviceViewSource.Source = _context.Devices
Upvotes: 3