ASP.NET MVC Notes - 01

2018-06-22 06:04:19来源：未知阅读 ()

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(50)=null,
     @Gender char(1)=null,
     @City nvarchar(50)=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 > 0)
            {
                return RedirectToAction("Index");
            }
            else
            {
                return View();
            } 
        }

View Code

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 > 0)
            {
                return RedirectToAction("Index");
            }
            else
            {
                return View();
            }
        }

View Code

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 = 0;
            if (ModelState.IsValid)
            {
                EmployeeService employeeService = new EmployeeService();
                numSucc = employeeService.AddEmployee(employee);
            } 

            if (numSucc > 0)
            {
                return RedirectToAction("Index");
            }
            else
            {
                return View();
            }
        }

View Code

Service 新增数据服务：

public int AddEmployee(Employee employee)
        {
            int numSucc = 0;
            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;
        }

View Code

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>
        }
    }

View Code

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; } 
    }

View Code

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);
        }

View Code

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");
            }

View Code

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);
        }

View Code

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());
        }

View Code

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