ASP.NET MVC 从入门到放弃(Day19)-MVC模型(Model)介绍

接下来讲讲Model 部分...

简单来说Model负责与资料库沟通的相关逻辑，或者定义模板(.cs)，或是使用Entity Framework自动产生资料库对应的模板(类别(.cs))後...交给Controoler去处理..

Category.cs 类别档

public class Category
{

   public int CateType { get; set; }
   public string CategoryID { get; set; }
   public string CategoryName { get; set; }

   public Category()//建构值
   {

   }

   public static List<Category> Get_Gategory(int id)
   {

            List<Category> result = new List<Category>();
            string connectionString = GlobalFunction.GlobalConnString;

            using (var conn = new MySqlConnection(connectionString))
            {

                conn.Open();

                using (var command = conn.CreateCommand())
                {
                    command.CommandText = "SELECT Category, Category_Name FROM Category WHERE CateType = @CateType";
                    command.Parameters.AddWithValue("@CateType", id);

                    using (var reader = command.ExecuteReader())
                    {
                        if (reader.HasRows)
                        {
                            while (reader.Read())
                            {
                                result.Add(new Category()
                                {
                                    CategoryID = (string)reader["Category"],
                                    CategoryName = (reader.IsDBNull(reader.GetOrdinal("Category_Name"))) ? "" : (string)reader["Category_Name"],
                                });
                            }
                            return result;
                        }
                        else
                        {
                            return result;
                        }
                    }
                }
            }
        }
}

上方public string CategoryName 就是类别档的模板， 接着再用Get_Gategory函式使用Ado 连线存在List 回传给Controoler

小帮手:如果要快速生成属性(property)

   public int CateType { get; set; } 

可以在类别档加入prop 按2次Tab键即可

补充说明:如果使用.Net6版本 属性(property) 预设要加入? (?代表允许Null)

   public int? CateType { get; set; } 

且显示画面Model要加入!

   @Model!.CateType

CategoryController.cs 控制器

public ActionResult Index(string id){
    var category = Category.Get_Category(id);
    return View(category);
}

Controoler收到资料後再透过return View() 将List资料丢给显示画面

Index.cshtml 显示画面

@model IEnumerable<WebApplication1.Models.Category.Category>
<table class="table">
    <tr>
        <th width="70">
            操作
        </th>
        <th width="70">
        </th>
        <th>
            @Html.DisplayNameFor(model => model.FirstOrDefault().CategoryID)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.FirstOrDefault().CategoryName)
        </th>
        <th>

        </th>
    </tr>
    @foreach (var md in this.Model)
    {
        <tr>
            <td>
                @Html.ActionLink("编辑", "Edit", new { Type = ViewBag.Type, categoryID = md.CategoryID }, new { @class = "glyphicon glyphicon-pencil" })
            </td>
            <td>

                @Html.ActionLink("删除", "Delete", new { Type = ViewBag.Type, categoryID = md.CategoryID }, new { @class = "glyphicon glyphicon-trash", @onclick = "return Confirm_Form('"+ md.CategoryID + "')" })
            </td>
            <td>@md.CategoryID</td>
            <td>@md.CategoryName</td>
        </tr>
    }
</table>

Model Class加入写法

Class1.cs 类别档

    public class Class1
    {
        public string Test1 { get; set; }
    }

Controller 传统写法

   Models.Class1 myClass = new Models.Class1();     
   myClass.Test1 = "Yaowen";

Controller 中期写法

    Models.Class1 myClass = new Models.Class1
   {
    
      myClass.Test1 = "Yaowen";
   };

VS2022的简化写法

    Models.Class1 myClass = new ()
   {
    
      myClass.Test1 = "Yaowen";
   };