Entity Framework (7), With .NET WPF, Database-First

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//     Manual changes to this file may cause unexpected behavior in your application.  
//     Manual changes to this file will be overwritten if the code is regenerated.  
// </auto-generated>  
//------------------------------------------------------------------------------  
  
namespace WPF_DatabaseFirst  
{  
    using System;  
    using System.Collections.Generic;  
      
    public partial class store  
    {  
        public string stor_id { get; set; }  
        public string stor_name { get; set; }  
        public string stor_address { get; set; }  
        public string city { get; set; }  
        public string state { get; set; }  
        public string zip { get; set; }  
    }  
} 

//------------------------------------------------------------------------------  
// <auto-generated>  
//     This code was generated from a template.  
//  
//     Manual changes to this file may cause unexpected behavior in your application.  
//     Manual changes to this file will be overwritten if the code is regenerated.  
// </auto-generated>  
//------------------------------------------------------------------------------  
  
namespace WPF_DatabaseFirst  
{  
    using System;  
    using System.Data.Entity;  
    using System.Data.Entity.Infrastructure;  
      
    public partial class pubsEntities : DbContext  
    {  
        public pubsEntities()  
            : base("name=pubsEntities")  
        {  
        }  
      
        protected override void OnModelCreating(DbModelBuilder modelBuilder)  
        {  
            throw new UnintentionalCodeFirstException();  
        }  
      
        public virtual DbSet<store> stores { get; set; }  
    }  
} 

and the connection details for the database will be inserted into app.config file,

<connectionStrings>  
  <add name="pubsEntities" connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=System.Data.SqlClient;provider connection string="data source=localhost;initial catalog=pubs;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />  
</connectionStrings> 

Step 2-1, Alternative Approach: Code First

In fact, the Code First approach for .NET Framework is quite simple, just using the entity class and context as created above, even the connection string is not necessary, as simple as these,

Entity class

namespace WPF_CodeFirst    
{    
    public partial class store    
    {    
        public string stor_id { get; set; }    
        public string stor_name { get; set; }    
        public string stor_address { get; set; }    
        public string city { get; set; }    
        public string state { get; set; }    
        public string zip { get; set; }    
    }    
}  

Context class

namespace WPF_CodeFirst    
{     
    using System.Data.Entity;     
        
    public partial class pubsEntities : DbContext    
    {             
        public virtual DbSet<store> stores { get; set; }    
    }    
} 

build the app, we have the database created automatically. See details from Article Entity Framework (1), with .Net MVC, Code-First,

Step 3 - Data Binding: Build the Grid, and Run the app

From both and either the Database First approach or Code First approach above, we got here for the next step: Data Binding, which is something of WPF different from Web module where we can use Scaffolder tool to build the CRUD (controller) using entity framework automatically.

In fact, for the Visual Studio 2010, our job has been almost done, as I described in my previous article WCF (4), RIA Services, that gave a entity database first approach for building a WPF app:

• We already have a DataSource available for Data Binding:
  
• Drag and Drop DataSource into XAML window
  
• Run the app, we got the Data Grid
  

However, for current Visual Studio, actually, after VS 2010, we need to do a little bit more work:

1, Build a Data Source Object:

• From the main menu, select Project => Add New Data Source … (in Visual Studio 2010, select Data => Add New Data Source…)

• In the Choose a Data Source Type window, select Object and click Next
  
  

• In the Select the Data Objects dialog, unfold the application name, here: WPF_DatabaseFirst two times and select data Store => Finish
  
  

• Now we have the Data Source (open: VS Main menu => View => Other Windows => Data Sources):
  

2, Build a Grid and link to Data Source:

• Drag and Drop DataSource into XAML window, however, we still cannot see the data after running the app:
  

This is because after dragging and dropping Data Source into Window, the window code behind does not really setup the connection to the data source as VS 2010 did,

public partial class MainWindow : Window  
{  
    public MainWindow()  
    {  
        InitializeComponent();  
    }  
  
    private void Window_Loaded(object sender, RoutedEventArgs e)  
    {  
        System.Windows.Data.CollectionViewSource storeViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("storeViewSource")));  
        // Load data by setting the CollectionViewSource.Source property:  
        // storeViewSource.Source = [generic data source]  
    }  
} 

Create a Context instance, and link the DataView Source to the Data Source:

public partial class MainWindow : Window  
{  
    private pubsEntities _context = new pubsEntities();  
    public MainWindow()  
    {  
        InitializeComponent();  
    }  
  
    private void Window_Loaded(object sender, RoutedEventArgs e)  
    {  
        System.Windows.Data.CollectionViewSource storeViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("storeViewSource")));  
        _context.stores.Load();  
  
        //Load data by setting the CollectionViewSource.Source property:   
        // storeViewSource.Source = [generic data source]  
        storeViewSource.Source = _context.stores.Local;  
    }  
} 

Now we have the result we want,

Step 4 - CURD

For Web app, after building entity framework, we can use Scaffolder to make CURD happen in controller. Now, we can view data, we need to add CUD:

Actually, add a save button in the Window, we can do the job:

• From the Toolbox, drag Button on to the form. Set the Content property to Save:
• Double Click the button, then add logic into the event handler:

  private void button_Click_1(object sender, RoutedEventArgs e)  
  {  
      // all changes are automatically tracked, including  
      // deletes!  
      _context.SaveChanges();  
    
      // this forces the grid to refresh to latest values  
      storeDataGrid.Items.Refresh();  
      //productsDataGrid.Items.Refresh();  
  } 

The Save button will do the CUD work:

Summary

The .NET WPF for Database-First approach is much similar to the web app, with a little bit more work. Here, we just discuss the basic concept to use Entity Framework to build a simple data driven app and see the similarity with Web apps, but we did not touch more complex issue for WPF exclusively. For example, for master/details data, the database first approach need to modify the auto created code, such as using ObservableCollection, instead of ICollection, see here for details. And we did not touch the major features for WPF, such as enforcing INotifyPropertyChanged interface to notice any data changes, The project did this by manually calling Refresh().

Reference

• Databinding with WPF --- MS
• Getting Started with WPF --- MS (Same as above, but for .NET Core)
• Entity Framework (1), with .Net MVC, Code-First --- Mine
• Entity Framework (2), with .Net MVC, Database-First --- Mine