Question

我正在使用asp.net mvc和entityframwork。我在我的模型中添加了一个新项目Linq - 到Sql类，我命名为：StickerPrinter.dbml。数据库是现有数据库

我添加了一个表：Verploegen_TEST_Location。

但是现在我尝试添加一个下拉列表。因为Verploegen_TEST_Location有五个位置。

见图片

我现在在mvc中有这个：

public ActionResult Index()
        {
            Verploegen_TEST_Location location = new Verploegen_TEST_Location();


        }

如果我在Verploegen_TEST_Location位置上执行f12，我会看到该表的所有属性。但我对Index方法有点挣扎。因为通常我使用这样的DBContext：

 public class StickerPrinterContext:DbContext
    {

        public StickerPrinterContext():base("StickerPrinterContext")
        {}

        public DbSet<Printer>printers  { get; set; }
        public DbSet<Vestiging>Vestigingen { get; set; }
        public DbSet <Vendor>Vendors  { get; set; }
        public DbSet<Verploegen_TEST_Location> Locations { get; set; }
    }

但我认为现在不需要在stickerPrinterContext中添加表格。

那么使用LINQ的下拉函数构建INdex方法？

谢谢

所以，如果我去Verploegen_TEST_Location，我会看到：

[global::System.Data.Linq.Mapping.TableAttribute(Name="dbo.[Verploegen TEST$Location]")]
    public partial class Verploegen_TEST_Location : INotifyPropertyChanging, INotifyPropertyChanged
    {

        private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);

        private System.Data.Linq.Binary _timestamp;

        private string _Code;

        private string _Name;

        private string _Name_2;

        private string _Address;

我的索引控制器就像这样：

public ActionResult Index()
        {
          IList<Verploegen_TEST_Location> locationList = new List<Verploegen_TEST_Location>();
            var query = from location in db.Locations
                        select location;

            return View(locationList);


        }

但如果我现在运行代码，我会收到此错误：

在模型生成期间检测到一个或多个验证错误：

StickerPrinterWeb.DAL.Verploegen_TEST_Location: : EntityType 'Verploegen_TEST_Location' has no key defined. Define the key for this EntityType.
Locations: EntityType: EntitySet 'Locations' is based on type 'Verploegen_TEST_Location' that has no keys defined

所以我所做的就是尝试在模型中添加一个新类：

public class Verploegen_TEST_Location
    {
    }

然后我会收到错误：

代码说明项目行列抑制状态 CS0260声明类型为“Verploegen_TEST_Location”时缺少部分修饰符;此类型的另一个部分声明存在StickerPrinterWeb 8 18 Active

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.42000
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>

我读过这个：

To conclude, Linq to Sql dbml file is an auto-generated file that you should never really need to look the code. The Visual Designer is powerful enough to handle all modifications possible with Linq to Sql.

但是如何处理INdex方法呢？

你的意思是我必须这样做？

[global::System.Data.Linq.Mapping.TableAttribute(Name="dbo.[Verploegen TEST$Location]")]
    public partial class Verploegen_TEST_Location : INotifyPropertyChanging, INotifyPropertyChanged
    {

        private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);

        private System.Data.Linq.Binary _timestamp;

        [Key]
        private string _Code;

        private string _Name;

        private string _Name_2;

        private string _Address;

因为上面的文件我看到了：

#pragma warning disable 1591
//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.42000
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

namespace StickerPrinterWeb.Models

我有一个像这样的viewModel：

public class Vm_LocationsList
    {
        [Key]
        public string _Code { get; set; }
        public string Name { get; set; }
    }

我现在就这样：

 public ActionResult Index()
        {
            // declare your view model if you have any
            var vm_LocationList = new Vm_LocationsList();

            var locationList = new List<Verploegen_TEST_Location>();
            var query = (from location in db.Locations
                         select location).ToList();

            var selectList = new List<SelectListItem>();

            foreach (var items in query)
            {
                selectList.Add(new SelectListItem { Text = items.Name, Value = items.Code });
            }

            model.SelectList = selectList;
            return View(model);
        }

但是模型的贬值在哪里？

好的，谢谢。但所以我没有必要编辑

[global::System.Data.Linq.Mapping.TableAttribute(Name="dbo.[Verploegen TEST$Location]")]
    public partial class Verploegen_TEST_Location : INotifyPropertyChanging, INotifyPropertyChanged
    {

        private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);

        private System.Data.Linq.Binary _timestamp;

        [Key]
        private string _Code;

我先做了什么？

但我仍然得到错误：

StickerPrinterWeb.DAL.Verploegen_TEST_Location: : EntityType 'Verploegen_TEST_Location' has no key defined. Define the key for this EntityType.

清晰度。这是我的Verploegen_TEST_Location：类的一部分：

#pragma warning disable 1591
//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.42000
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

namespace StickerPrinterWeb.Models
{
    using System.Data.Linq;
    using System.Data.Linq.Mapping;
    using System.Data;
    using System.Collections.Generic;
    using System.Reflection;
    using System.Linq;
    using System.Linq.Expressions;
    using System.ComponentModel;
    using System;
    using System.ComponentModel.DataAnnotations;

    [global::System.Data.Linq.Mapping.DatabaseAttribute(Name="VERPLOEGEN-NAV2009R2-TEST")]
    public partial class StickerPrinterDataContext : System.Data.Linq.DataContext
    {

        private static System.Data.Linq.Mapping.MappingSource mappingSource = new AttributeMappingSource();

    #region Extensibility Method Definitions
    partial void OnCreated();
    partial void InsertVerploegen_TEST_Location(Verploegen_TEST_Location instance);
    partial void UpdateVerploegen_TEST_Location(Verploegen_TEST_Location instance);
    partial void DeleteVerploegen_TEST_Location(Verploegen_TEST_Location instance);
    #endregion

        public StickerPrinterDataContext() : 
                base(global::System.Configuration.ConfigurationManager.ConnectionStrings["VERPLOEGEN_NAV2009R2_TESTConnectionString"].ConnectionString, mappingSource)
        {
            OnCreated();
        }

        public StickerPrinterDataContext(string connection) : 
                base(connection, mappingSource)
        {
            OnCreated();
        }

        public StickerPrinterDataContext(System.Data.IDbConnection connection) : 
                base(connection, mappingSource)
        {
            OnCreated();
        }

        public StickerPrinterDataContext(string connection, System.Data.Linq.Mapping.MappingSource mappingSource) : 
                base(connection, mappingSource)
        {
            OnCreated();
        }

        public StickerPrinterDataContext(System.Data.IDbConnection connection, System.Data.Linq.Mapping.MappingSource mappingSource) : 
                base(connection, mappingSource)
        {
            OnCreated();
        }

        public System.Data.Linq.Table<Verploegen_TEST_Location> Verploegen_TEST_Locations
        {
            get
            {
                return this.GetTable<Verploegen_TEST_Location>();
            }
        }
    }

    [global::System.Data.Linq.Mapping.TableAttribute(Name="dbo.[Verploegen TEST$Location]")]
    public partial class Verploegen_TEST_Location : INotifyPropertyChanging, INotifyPropertyChanged
    {

        private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);

        private System.Data.Linq.Binary _timestamp;

        [Key]
        private string _Code;

        private string _Name;

        private string _Name_2;

        private string _Address;

        private string _Address_2;

        private string _City;

        private string _Phone_No_;

        private string _Phone_No__2;

        private string _Telex_No_;

        private string _Fax_No_;

        private string _Contact;

        private string _Post_Code;

        private string _County;

        private string _E_Mail;

        private string _Home_Page;

        private string _Country_Region_Code;

        private byte _Use_As_In_Transit;

        private byte _Require_Put_away;

        private byte _Require_Pick;

        private string _Cross_Dock_Due_Date_Calc_;

        private byte _Use_Cross_Docking;

        private byte _Require_Receive;

        private byte _Require_Shipment;

        private byte _Bin_Mandatory;

        private byte _Directed_Put_away_and_Pick;

        private int _Default_Bin_Selection;

        private string _Outbound_Whse__Handling_Time;

        private string _Inbound_Whse__Handling_Time;

        private string _Put_away_Template_Code;

        private byte _Use_Put_away_Worksheet;

        private byte _Pick_According_to_FEFO;

        private byte _Allow_Breakbulk;

        private int _Bin_Capacity_Policy;

        private string _Open_Shop_Floor_Bin_Code;

        private string _Inbound_Production_Bin_Code;

        private string _Outbound_Production_Bin_Code;

        private string _Adjustment_Bin_Code;

        private byte _Always_Create_Put_away_Line;

        private byte _Always_Create_Pick_Line;

        private int _Special_Equipment;

        private string _Receipt_Bin_Code;

        private string _Shipment_Bin_Code;

        private string _Cross_Dock_Bin_Code;

        private string _Outbound_BOM_Bin_Code;

        private string _Inbound_BOM_Bin_Code;

        private string _Base_Calendar_Code;

        private byte _Use_ADCS;

        private string _Counter_Nos_;

        private string _Payment_Method_comb_;

        private string _Account_No__Cash;

        private string _Account_No__Pay_Card;

        private string _Account_No__Cash_Deliver;

        private string _Account_No__Pay_Card_Deliver;

        private decimal _X_coord;

        private decimal _Y_coord;

        private byte _Autom__Create_Whse__Shipment;

        private byte _Block_for_Item_Availability;

        private string _Printer_Name;

Answer 1

我查看了您的第一条错误消息：

Locations: EntityType: EntitySet 'Locations' is based on type 'Verploegen_TEST_Location' that has no keys defined

根据我的经验，请确保在所有DBML模型类主键字段/属性中添加KeyAttribute以在DbSet上下文中使用它们（可能需要在DBML设计器文件上手动编辑，或者在底层数据库上添加主键，然后重新生成DBML结构。）

关于第二条错误消息：

CS0260: Missing partial modifier on declaration of type 'Verploegen_TEST_Location'; another partial declaration of this type exists

由于模型类被声明为partial，因此您无需在其上添加其他相同的模型类而不使用partial修饰符，但您可以创建单独的视图模型以与视图进行通信并将CRUD执行到模型类中。

如果您已经在所有DBML表类上设置了主键字段/属性，则可以尝试使用List<SelectListItem>或Html.DropDownList将下拉列表内容作为Html.DropDownListFor传递到视图中。

编辑：我修改了给定的示例以适合您的代码说明，包括Model＆amp;控制器例程在这里：

// Model
public class Vm_LocationsList
{
    [Key]
    public string _Code { get; set; }
    public string Name { get; set; }

    // add this line to include drop down list items to your view
    public List<SelectListItem> SelectList { get; set; }
}

// Controller
public ActionResult Index()
{
    // this is your view model declaration
    var vm_LocationList = new Vm_LocationsList();

    var locationList = new List<Verploegen_TEST_Location>();
    var query = (from location in db.Locations
                 select location).ToList();

    var selectList = new List<SelectListItem>();

    foreach (var items in query)
    {
        selectList.Add(new SelectListItem { Text = items.Name, Value = items.Code });
    }

    vm_LocationList.SelectList = selectList;
    return View(vm_LocationList);
}

// View (strongly-typed version)
@Html.DropDownListFor(m => m.Code, Model.SelectList)

欢迎任何建议。

来自外部数据库

1 个答案: