ASP.NET MVC Notes

inetmgr 进入IIS
ViewBag和ViewData在run-time的时候检查错误，View中的用法如下：

   @*ViewBag传递的是动态对象*@

    @foreach (string item in ViewBag.listData)

    {

        <li>@item</li>

    }

    -----------------------------------------

    @*ViewData传递的是Object,所以要转换类型*@

    @foreach (string item in (List<string>)ViewData["Countries"])

    {

        <li>@item</li>

    }

web.config中连接字符串名称需要和DbContext的类名称一致：

public class EmployeeContext : DbContext

    {

        //定义对应到数据库表的对象集合

        public DbSet<Employee> Employees { get; set; }

    }

    <add name="EmployeeContext"

         providerName="System.Data.SqlClient"

         connectionString="Data Source=.;Initial Catalog=MVCSample;User ID= ;Password= ; "  />

Global.ashx 程序运行初始化配置：

//DBFirst从数据读取数据，程序运行的时候EmployeeContext初始化为Null

    Database.SetInitializer<MVCBlog.Models.EmployeeContext>(null);

View需要List数组对象，则强类型直接定义为IEnumerable; View中@using引用需要用到的类

@model IEnumerable<MVCBlog.Models.Employee>

@using MVCBlog.Models

@{

    ViewBag.Title = "Index";

    Layout = "~/Views/Shared/_Layout.cshtml";

}

<h2>Index</h2>

@*Controller 传递过来的是List对象,所以强类型定义为List<MVCBlog.Models.Employee>*@

<ul>

    @foreach (Employee employee in @Model)

    {

        <li> @Html.ActionLink(employee.Name, "Details", new { @id = @employee.EmployeeID })  </li>

    }

</ul>

业务逻辑层获取数据

public IEnumerable<Employee> employees

        {

            get

            {

                string connectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;

                List<Employee> employees = new List<Employee>();

                using (SqlConnection con = new SqlConnection(connectionString))

                {

                    SqlCommand cmd = new SqlCommand("sp_GetAllEmployee", con);

                    cmd.CommandType = CommandType.StoredProcedure;

                    con.Open();

                    SqlDataReader sdr = cmd.ExecuteReader();

                    while (sdr.Read())

                    {

                        Employee employee = new Employee();

                        employee.EmployeeID = Convert.ToInt32(sdr["EmployeeID"]);

                        employee.Name = sdr["Name"].ToString();

                        employee.City = sdr["City"].ToString();

                        employee.Gender = Convert.ToChar(sdr["Gender"]); 

                        employees.Add(employee);

                    }

                    return employees;

                }

            }

        }

Razor中构建DropList:

  @Html.DropDownList("Gender", new List<SelectListItem> {

                      new SelectListItem { Text="男",Value="M"},

                      new SelectListItem{ Text="女",Value="F"}

                }, "Select Gender", htmlAttributes: new { @class = "control-label col-md-2" })
  //或者是在Controller中构建SelectList后，Razor中Render
  ViewBag.DepartID = new SelectList(db.Department, "ID", "Name", employee.DepartID); 

  @Html.DropDownList("DepartID", null, "Select Department",htmlAttributes: new { @class = "form-control" })

Procedure AddEmployee

CREATE PROCEDURE sp_AddEmployee

     @Name nvarchar()=null,

     @Gender char()=null,

     @City nvarchar()=null,

     @DateOfBirth DateTime=null

AS

BEGIN

    -- SET NOCOUNT ON added to prevent extra result sets from

    -- interfering with SELECT statements.

    Insert Into Employee(Name,Gender,City,DateOfBirth)

    values(@Name,@Gender,@City,@DateOfBirth)

END

GO

Controller搜集从View页面Post过来的数据，有三种方法：

FormCollection 中包含了所有表单数据的键值对集合，通过FromCollection[Key] 访问到View Post 过来的 Data

 [HttpPost]

        public ActionResult Create(FormCollection formCollection)

        {

            //foreach (string key in formCollection.AllKeys)

            //{

            //    Response.Write(key + " ");

            //    Response.Write(formCollection[key] + "<br/>");

            //}

            Employee employee = new Employee();

            employee.Name = formCollection["Name"];

            employee.Gender = Convert.ToChar(formCollection["Gender"]);

            employee.City = formCollection["City"];

            employee.DateOfBirth = Convert.ToDateTime(formCollection["DateOfBirth"]);

            EmployeeService employeeService = new EmployeeService();

            int numSucc = employeeService.AddEmployee(employee);

            if (numSucc > )

            {

                return RedirectToAction("Index");

            }

            else

            {

                return View();

            }

        }

直接以参数的形式接收数据

 [HttpPost]

        public ActionResult Create(string Name,char Gender,string City,string DateOfBirth)

        {

            Employee employee = new Employee();

            employee.Name = Name;

            employee.Gender = Gender;

            employee.City = City;

            employee.DateOfBirth = Convert.ToDateTime(DateOfBirth);

            EmployeeService employeeService = new EmployeeService();

            int numSucc = employeeService.AddEmployee(employee);

            if (numSucc > )

            {

                return RedirectToAction("Index");

            }

            else

            {

                return View();

            }

        }

Controller中UpdaetModel 更新 Model，获得提交过来的数据

 [HttpPost]

        [ActionName("Create")]

        public ActionResult Create_Post()

        {

            Employee employee = new Employee();

            UpdateModel<Employee>(employee);

            int numSucc = ;

            if (ModelState.IsValid)

            {

                EmployeeService employeeService = new EmployeeService();

                numSucc = employeeService.AddEmployee(employee);

            } 

            if (numSucc > )

            {

                return RedirectToAction("Index");

            }

            else

            {

                return View();

            }

        }

Service 新增数据服务：

public int AddEmployee(Employee employee)

        {

            int numSucc = ;

            using (SqlConnection conn = new SqlConnection(connectionString))

            {

                SqlCommand cmd = new SqlCommand("sp_AddEmployee", conn);

                cmd.CommandType = CommandType.StoredProcedure;

                SqlParameter[] paras = new SqlParameter[] {

                    new SqlParameter("Name",employee.Name),

                    new SqlParameter("Gender",employee.Gender),

                    new SqlParameter("City",employee.City),

                    new SqlParameter("DateOfBirth",employee.DateOfBirth)

                };

                cmd.Parameters.AddRange(paras);

                conn.Open();

                numSucc = cmd.ExecuteNonQuery();

            }

            return numSucc;

        }

解决方案中的Nuget包管理器对解决方案中的Nuget包进行管理。
Controller中模型绑定的两种方法：
1,Bind 制定需要进行模型绑定传递到Controller中的数据。
```
public ActionResult Edit_Post([Bind(Include = "Gender , City,DateOfBirth")]Employee employee)
```
2，在UpdateModel中，传递需要更新或者是不需要更新的参数
```
UpdateModel<Employee>(employee, null, null, new string[] { "Name" });
```
3，定义IEmployee接口，Employee继承自IEmployee.
```
UpdateModel<IEmployee>(employee);
```

进行数据的Delete动作必须在Post数据中执行

  @foreach (var item in Model)

    {

        using (Html.BeginForm("Delete", "Employee", new { id = item.ID }))

        {

            <tr>

                <td>

                    @Html.DisplayFor(modelItem => item.Name)

                </td>

                <td>

                    @Html.DisplayFor(modelItem => item.Gender)

                </td>

                <td>

                    @Html.DisplayFor(modelItem => item.City)

                </td>

                <td>

                    @Html.DisplayFor(modelItem => item.DateOfBirth)

                </td>

                <td>

                    @Html.ActionLink("Edit", "Edit", new { id = item.ID }) |

                    @Html.ActionLink("Details", "Details", new { id = item.ID }) |

                    <input type="submit" value="Delete"  onclick="return confirm('确定删除 @item.Name 吗 ')" />

                </td>

            </tr>

        }

    }

EF中字段属性的控制，如：[Required]、[Display(Name="")] 需在partial class中进行处理

[MetadataType(typeof(EmployeeMetaData))]

    public partial class Employee

    {

    }

    public class EmployeeMetaData

    {

        [Required]

        [Display(Name = "姓名")]

        public string Name { get; set; }

        [Required]

        [Display(Name = "性别")]

        public char Gender { get; set; }

        [Required]

        [Display(Name = "所在城市")]

        public string City { get; set; }

        [Required]

        [Display(Name = "生日")]

        public DateTime DateOfBirth { get; set; }

        [Required]

        [Display(Name = "部门")]

        public int DepartID { get; set; }

    }

Edit信息的时候不需要更新字段的处理，如不需要更新Name。

partial class 中去掉 [Required]
Edit方法中用查出来的实体来存储更新后的数据

 [HttpPost]

        [ValidateAntiForgeryToken]

        public ActionResult Edit([Bind(Include = "ID,Gender,City,DateOfBirth,DepartID")] Employee employee)

        {

            Employee employeeFromDB = db.Employee.Find(employee.ID);

            //须要用你查出来的实体来存储更新后的数据，不更新Name字段

            employeeFromDB.City = employee.City;

            employeeFromDB.Gender = employee.Gender;

            employeeFromDB.DepartID = employee.DepartID;

            employeeFromDB.DateOfBirth = employee.DateOfBirth;

            if (ModelState.IsValid)

            {

                db.Entry(employeeFromDB).State = EntityState.Modified;

                db.SaveChanges();

                return RedirectToAction("Index");

            }

            ViewBag.DepartID = new SelectList(db.Department, "ID", "Name", employee.DepartID);

            return View(employee);

        }

Controller的Create方法中必需的字段，添加验证检查处理

 if (string.IsNullOrEmpty(employee.Name))

            {

                ModelState.AddModelError("Name", "姓名为必需字段");

            }

Lambda表达式，统计Department下Employee数量

 [HttpGet]

        public ActionResult EmployeeByDepartment()

        {

            var departmentTotals = db.Employee.Include("Department")

                .GroupBy(d => d.Department.Name)

                .Select(y => new DepartmentTotals

                {

                    Name = y.Key,

                    Total = y.Count()

                }).ToList().OrderByDescending(y => y.Total);

            return View(departmentTotals);

        }

Controller中Return View()中如果指定带有后缀的View,如index.cshtml，则需要传递完整路径：

 public ActionResult Index()

        {

            var employee = db.Employee.Include(e => e.Department);

            return View("~/Views/Employee/Index.cshtml",employee.ToList());

        }

巴特西

ASP.NET MVC Notes - 01

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