《Entity Framework 6 Recipes》中文翻译——第九章EntityFramework在N层架构程序中的应用（一）

public class Order
{
    public int Order Id { get; set; }
    public string Product { get; set; }
    public int Quantity { get; set; }
    public string Status { get; set; }
    public byte[] Time Stamp { get; set; }
}

public class Recipe1Context : Db Context
{
    public Recipe1Context() : base("Recipe1Connection String") { }
 
    public Db Set<Order> Orders { get; set; }
  
    protected override void On Model Creating(Db Model Builder model Builder)
    {
        model Builder.Entity<Order>().To Table("Chapter9.Order");
        // Following configuration enables timestamp to be concurrency token
        model Builder.Entity<Order>().Property(x => x.Time Stamp)
            .Is Concurrency Token()
            .Has Database Generated Option(Database Generated Option.Computed);
    }
}

<connection Strings>
  <add name="Recipe1Connection String"
    connection String="Data Source=.;
       Initial Catalog=EFRecipes;
       Integrated Security=True;
       Multiple Active Result Sets=True"
    provider Name="System.Data.Sql Client" />
</connection Strings>

protected void Application_Start()
{
    // Disable Entity Framework Model Compatibilty
    Database.Set Initializer<Recipe1Context>(null);
    ...
}

public class Order Controller : Api Controller
{
    // GET api/order
    public IEnumerable<Order> Get()
    {
        using (var context = new Recipe1Context())
        {
            return context.Orders.To List();
        }
    }
  
    // GET api/order/5
    public Order Get(int id)
    {
        using (var context = new Recipe1Context())
        {
            return context.Orders.First Or Default(x => x.Order Id == id);
        }
    }
  
    // POST api/order
    public Http Response Message Post(Order order)
    {
        // Cleanup data from previous requests
        Cleanup();
 
        using (var context = new Recipe1Context())
        {
            context.Orders.Add(order);
            context.Save Changes();
  
            // create Http Response Message to wrap result, assigning Http Status code of 201,
            // which informs client that resource created successfully
            var response = Request.Create Response(Http Status Code.Created, order);
 
            // add location of newly-created resource to response header
                            response.Headers.Location = new Uri(Url.Link("Default Api",  
new { id = order.Order Id }));
                 
            return response;
        }
    }

// PUT api/order/5
    public Http Response Message Put(Order order)
    {
        using (var context = new Recipe1Context())
        {
            context.Entry(order).State = Entity State.Modified;
            context.Save Changes();
                  
    // return Http Status code of 200, informing client that resouce updated successfully
            return Request.Create Response(Http Status Code.OK, order);
        }
    }
// DELETE api/order/5
    public Http Response Message Delete(int id)
    {
        using (var context = new Recipe1Context())
        {
                var order = context.Orders.First Or Default(x => x.Order Id == id);
                context.Orders.Remove(order);
                context.Save Changes();
          // Return Http Status code of 200, informing client that resouce removed successfully
          return Request.Create Response(Http Status Code.OK);
        }
    }
  
    private void Cleanup()
    {
        using (var context = new Recipe1Context())
        {
            context.Database.Execute Sql Command("delete from chapter9.[order]");
        }
    }
}

private Http Client _client;
private Order _order;
 
private static void Main()
{
    Task t = Run();
    t.Wait();
    Console.Write Line("\n Press <enter> to continue...");
    Console.Read Line();
}
  
private static async Task Run()
{
    // create instance of the program class
    var program = new Program();
    program.Service Setup();
    program.Create Order();
    // do not proceed until order is added
    await program.Post Order Async();
    program.Change Order();
    // do not proceed until order is changed
     await program.Put Order Async();
    // do not proceed until order is removed
   await  program.Remove Order Async();
}
  
private void Service Setup()
{
    // map URL for Web API cal
    _client = new Http Client { Base Address = new Uri("http://localhost:3237/") };
  
    // add Accept Header to request Web API content
    // negotiation to return resource in JSON format
    _client.Default Request Headers.Accept.
        Add(new Media Type With Quality Header Value("application/json"));
}
  
private void Create Order()
{
    // Create new order
    _order = new Order { Product = "Camping Tent", Quantity = 3, Status = "Received" };
}
  
private async Task Post Order Async()
{
    // leverage Web API client side API to call service
    var response = await _client.Post As Json Async("api/order", _order);
    Uri new Order Uri;
  
    if (response.Is Success Status Code)
    {
        // Capture Uri of new resource
        new Order Uri = response.Headers.Location;
  
        // capture newly-created order returned from service,
        // which will now include the database-generated Id value
        _order = await response.Content.Read As Async<Order>();
        Console.Write Line("Successfully created order. Here is URL to new resource: {0}", new Order Uri);
    }
    else
        Console.Write Line("{0} ({1})", (int)response.Status Code, response.Reason Phrase);
}
  
private void Change Order()
{
    // update order
    _order.Quantity = 10;
}
private async Task Put Order Async()
{
    // construct call to generate Http Put verb and dispatch
    // to corresponding Put method in the Web API Service
    var response = await _client.Put As Json Async("api/order", _order);
  
    if (response.Is Success Status Code)
    {
        // capture updated order returned from service, which will include new quanity
        _order = await response.Content.Read As Async<Order>();
        Console.Write Line("Successfully updated order: {0}", response.Status Code);
    }
    else
        Console.Write Line("{0} ({1})", (int)response.Status Code, response.Reason Phrase);
}
  
private async Task Remove Order Async()
{
    // remove order
    var uri = "api/order/" + _order.Order Id;
    var response = await _client.Delete Async(uri);
  
    if (response.Is Success Status Code)
        Console.Write Line("Sucessfully deleted order: {0}", response.Status Code);
    else
        Console.Write Line("{0} ({1})", (int)response.Status Code, response.Reason Phrase);
 }