新的开始 接触ASP.NET Core跨平台的框架

       今天我刚学习了使用Visual Studio 2015新建了.NET Core项目写了一个小的CSHTML代码。按我的话说就是，把C#和HTML合起来使用了，
写了一个简单的关于学生的“增” “删” “改"  "查"的一系列的代码(只是一个简单的关于的学生的“增” “删” “改"  "查"代码哦)。
       今天可以说是我第一次接触CSHTML，学会了把简单的代码在网页上显示出来。
       这种技术叫ASP.NET Core是一个全新的跨平台的框架，主要用于架构如Web应用等连接互联网的现代应用程序，可以在Windows上跨平台
开发和运行你的ASP.NET Core应用。

一开始就从数据库查询所须的条件

public IActionResult Index()
      {
          var list = new List<Dictionary<string, dynamic>>(); //用字典接收每一个事物的所有值
          using (var con = new SqlConnection("server=.;database=MySchool;uid=sa;pwd=ljk123;"))
          //连接数据库
          {
              var cmd = new SqlCommand();
              cmd.Connection = con;
              cmd.CommandText = @"select StudentNo,StudentName,Sex,t2.GradeName from Student t1 ,Grade t2
                                  where t1.GradeId= t2.GradeId";
              //按传递的Sql语句执行操作
              con.Open();
              var dr = cmd.ExecuteReader();
              while (dr.Read())
              {
                  list.Add(Enumerable.Range(0, dr.FieldCount).ToDictionary(dr.GetName, dr.GetValue));
              }
              //循环遍历
          }
          ViewData["Persons"] = list; //将遍历出来的值赋到ViewData["变量名"]中。
          return View();
      }

然后在Imdex中按表单的形式查询所查学生的信息

<table border="0" title="添加">
    <caption>添加信息</caption>
    <tr>
        <th>学号</th>
        <th>姓名</th>
        <th>性别</th>
        <th>年级</th>
    </tr>
    <tr>
        <td imput type=text></td>
        <td imput type=text></td>
        <td imput type=text></td>
        <td imput type=text></td>
    </tr>
</table>
<table class="table table-bordered table-hover table-condensed table-responsive table-striped">
    <thead>
        <tr>
            <th>学号</th>
            <th>姓名</th>
            <th>性别</th>
            <th>年级</th>
            <th>操作</th>
        </tr>
    </thead>
    <tbody>
        @foreach (var item in ViewData["Persons"] as System.Collections.Generic.List<Dictionary<string,dynamic>>)
        {
        <tr>
            <td>@item["StudentNo"]</td>
            <td>@item["StudentName"]</td>
            <td>@item["Sex"]</td>
            <td>@item["GradeName"]</td>
            <td>
                <a class="btn btn-success" href="/home/modify?bh=@item["StudentNo"]">修改</a>
                <button class="btn btn-danger"  onclick="deletestu('@item["StudentNo"]')">删除</button>
            </td>
        </tr>
        } 
    </tbody>   
</table>

然后在HomeController中添加学生信息（Get Post）

[HttpGet]
       public IActionResult Add()
       {
           ViewData["Message"] = "Your application description page.";

           return View();
       }
       [HttpPost]
       public IActionResult Add(string mc, string bh, string gen, int nj)
       {
           var list = new List<Dictionary<string, dynamic>>(); //用字典接收每一个事物的所有值
           using (var con = new SqlConnection("server=.;database=MySchool;uid=sa;pwd=ljk123;"))
           //连接数据库
           {
               var cmd = new SqlCommand();
               cmd.Connection = con;
               cmd.CommandText = $@"insert into Student(StudentNo,StudentName,Sex,GradeId)
                                     values('{bh}','{mc}','{gen}',{nj})";
               //按传递的Sql语句执行操作
               con.Open();
               var dr = cmd.ExecuteNonQuery();
               if (dr > 0)
               {
                   return Redirect("/home/index");
               }
               else
               {
                   ViewData["Message"] = "添加失败！";
                   return View();
               }
           }
       }

在add按表单排版，"添加"新的学生信息

<form method="post" action="/home/add">
    <p>学生编号：<input name="bh" class="form-control" type="text"></p>
    <p>学生姓名：<input name="mc" class="form-control" type="text"></p>
    性&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp别：
    <input name="gen" type="radio" class="input" value="男" checked="checked">男 

    <input name="gen" type="radio" class="input" value="女">女 <br />
    年&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp级：
     <select name="nj">
         <option value="1">S1</option>
         <option value="2">S2</option>
         <option value="3">Y2</option>
         <option value="1" selected="selected">S1</option>

     </select> <br /><br />
    &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp
    <input type="reset" name="Reset" value="重填">&nbsp&nbsp&nbsp&nbsp
    <input type="submit" name="Submit" value="提交">
</form>
@ViewData["Message"]

　　在HomeController中修改学生信息（Get Post）

[HttpGet]
        public IActionResult Modify(string bh)
        {
            ViewData["Message"] = "Your contact page.";
            Dictionary<string, dynamic> dic = null;
            using (var con = new SqlConnection("server=.;database=MySchool;uid=sa;pwd=ljk123;"))
            //连接数据库
            {
                var cmd = new SqlCommand();
                cmd.Connection = con;
                cmd.CommandText = $@"select StudentNo,StudentName,Sex,GradeId from Student
                                    where StudentNo= '{bh}'";
                //按传递的Sql语句执行操作
                con.Open();
                var dr = cmd.ExecuteReader();

                while (dr.Read())
                {
                    dic = (Enumerable.Range(0, dr.FieldCount).ToDictionary(dr.GetName, dr.GetValue));
                }
                //循环遍历
            }
            ViewData["Person"] = dic; //将遍历出来的值赋到ViewData["变量名"]中。
            return View();
        }
        [HttpPost]
        public IActionResult Modify(string mc, string bh, string gen, int nj)
        {
            var list = new List<Dictionary<string, dynamic>>(); //用字典接收每一个事物的所有值
            using (var con = new SqlConnection("server=.;database=MySchool;uid=sa;pwd=ljk123;"))
            //连接数据库
            {
                var cmd = new SqlCommand();
                cmd.Connection = con;
                cmd.CommandText = $@"update Student set StudentNo = '{bh}',StudentName='{mc}',Sex='{gen}',GradeId='{nj}'
                              where StudentNo = '{bh}'";
                //按传递的Sql语句执行操作
                con.Open();
                var dr = cmd.ExecuteNonQuery();
                if (dr > 0)
                {
                    return Redirect("/home/index");
                }
                else
                {
                    ViewData["Message"] = "更新失败！";
                    return View();
                }
            }
            return View();
        }

　通过把学生的编号传过去修改

 <a class="btn btn-success" href="/home/modify?bh=@item["StudentNo"]">修改</a>

　　

　在Midify中排版修改

<form method="post" action="/home/Modify">
    <p>学生编号：<input name="bh" class="form-control" disabled="disabled" type="text" value="@((ViewData["Person"] as Dictionary<string, dynamic>)["StudentNo"])"></p>
    <p>学生姓名：<input name="mc" class="form-control" type="text" value="@((ViewData["Person"] as Dictionary<string, dynamic>)["StudentName"])"></p>
    性&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp别：
    @if ((ViewData["Person"] as Dictionary<string, dynamic>)["Sex"] == "男")
    {
        <input name="gen" type="radio" class="input" value="男" checked="checked"><span>男</span>
        <input name="gen" type="radio" class="input" value="女"><span>女</span>
    }
    else
    {
        <input name="gen" type="radio" class="input" value="男"><span>男</span>
        <input name="gen" type="radio" class="input" value="女" checked="checked"><span>女</span>
    }
    </br>年&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp级：

    <select name="nj">
        @if ((ViewData["Person"] as Dictionary<string, dynamic>)["GradeId"] == 1)
        {
            <option value="1" selected="selected">S1</option>
            <option value="2">S2</option>
            <option value="3">Y2</option>
        }
        else if (((ViewData["Person"] as Dictionary<string, dynamic>)["GradeId"] == 2))
        {
            <option value="1">S1</option>
                <option value="2" selected="selected">S2</option>
                <option value="3">Y2</option>
        }
        else
        {
            <option value="1">S1</option>
                <option value="2">S2</option>
                <option value="3" selected="selected">Y2</option>
        }
    </select> <br /><br />
     <input type="reset" name="Reset" value="重填">
     <input type="submit" name="Submit" value="提交">
  </form>

　　最后是删除了通过接收到的编号进行删除

<button class="btn btn-danger"  onclick="deletestu('@item["StudentNo"]')">删除</button>

　　在HomeController中删除学生信息（post）

[HttpPost]
        public string Delete(string bh)
        {
            ViewData["Message"] = "Your contact page.";

            using (var con = new SqlConnection("server=.;database=MySchool;uid=sa;pwd=ljk123;"))
            //连接数据库
            {
                var cmd = new SqlCommand();
                cmd.Connection = con;
                cmd.CommandText = $@"delete from Student
                                    where StudentNo= '{bh}'";
                //按传递的Sql语句执行操作
                con.Open();
                var dr = cmd.ExecuteNonQuery();
                if (dr > 0)
                {
                    return "删除成功！";
                }
                else
                {
                    return "删除失败！";
                }
            }
        }

　最后在用AJAX进行删除　

<script>    //定义客户端脚本
    function deletestu(bh)   // function	功能，作用;
    {
        if (confirm("确定要删除吗？")) {
            $.post("/home/delete", { bh: bh }, function (result) {

                alert(result);
                window.location.href="/home/index";
            })
        }
    }
</script>