ASP.NET MVC Notes - 01

2018-06-22 06:04:19来源:未知 阅读 ()

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  1. inetmgr 进入IIS
  2. ViewBag和ViewData在run-time的时候检查错误,View中的用法如下: 
  3.    @*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>
        }
  4. web.config中连接字符串名称需要和DbContext的类名称一致:
  5. 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= ; "  />
  6. Global.ashx 程序运行初始化配置:
  7. //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);
  8. 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 
  9. @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>
  10. 业务逻辑层获取数据
  11. 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;
                    }
                }
            }
  12. Razor中构建DropList:
  13.   @Html.DropDownList("Gender", new List<SelectListItem> {
                          new SelectListItem { Text="",Value="M"},
                          new SelectListItem{ Text="",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" })
  14. Procedure AddEmployee
  15. 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
  16. Controller搜集从View页面Post过来的数据,有三种方法:
    1. 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
      1.  [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
    2. 直接以参数的形式接收数据
      1.  [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
    3. Controller中UpdaetModel 更新 Model,获得提交过来的数据 
      1.  [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
  17. Service  新增数据服务:
    1. 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
  18. 解决方案中的Nuget包管理器对解决方案中的Nuget包进行管理。
  19. 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);
  20. 进行数据的Delete动作必须在Post数据中执行
    1.   @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
  21. EF中字段属性的控制,如:[Required]、[Display(Name="")]  需在partial class中进行处理
    1. [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
  22. Edit信息的时候不需要更新字段的处理,如不需要更新Name。
    1. partial class 中 去掉 [Required]
    2. Edit方法中用 查出来的实体来存储更新后的数据
    3.  [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
    4. Controller的Create方法中必需的字段,添加验证检查处理
    5.  if (string.IsNullOrEmpty(employee.Name))
                  {
                      ModelState.AddModelError("Name", "姓名为必需字段");
                  }
      View Code
  23. Lambda表达式,统计Department下Employee数量
    1.  [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
  24. 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:
    1.  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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