EasyUI 之 DataGrid利用用拉姆达表达式实现分页查询

  首先，我们在DataGrid的URL中加上我们要查询的条件：查询用户名不是“呵呵”的所有用户。

<div>
        <table id="dg" class="easyui-datagrid" style=" 600px; height: 350px" >
            <thead>
                <tr>
                    <th data-options="field:'UserID',148,sortable:true">ID</th>
                    <th data-options="field:'UserName',148,sortable:true">姓名</th>
                    <th data-options="field:'Sex',148,sortable:true">性别</th>
                </tr>
            </thead>

        </table>
    </div>

    <!--datagrid基本设置-->
    <script type="text/javascript">
        $(function () {
            $('#dg').datagrid({
                title: '测试表格',
                url: "/EvaluationSituation/jsonTest?strUserName=呵呵", //添加查询条件
                pagination: true,//显示分页工具栏
                fitColumns: true, //自动大小

            });
        });
    </script>

        然后我们在后台接收参数，并执行查询

public JsonResult  jsonTest()
       {
           #region 制造假数据
           List<User> listUser = new List<User>();

           listUser.Add(new User {
               UserID ="001",
               UserName="呵呵",
               Sex ="男"
           });
           listUser.Add(new User
           {
               UserID = "002",
               UserName = "哈哈",
               Sex = "女"
           });
           listUser.Add(new User
           {
               UserID = "003",
               UserName = "嘿嘿",
               Sex = "男"
           });
           listUser.Add(new User
           {
               UserID = "004",
               UserName = "嘻嘻",
               Sex = "男"
           });
           listUser.Add(new User
           {
               UserID = "002",
               UserName = "哈哈",
               Sex = "女"
           });
           listUser.Add(new User
           {
               UserID = "003",
               UserName = "嘿嘿",
               Sex = "男"
           });
           listUser.Add(new User
           {
               UserID = "004",
               UserName = "嘻嘻",
               Sex = "男"
           });
           listUser.Add(new User
           {
               UserID = "002",
               UserName = "哈哈",
               Sex = "女"
           });
           listUser.Add(new User
           {
               UserID = "003",
               UserName = "嘿嘿",
               Sex = "男"
           });
           listUser.Add(new User
           {
               UserID = "004",
               UserName = "嘻嘻",
               Sex = "男"
           });
           listUser.Add(new User
           {
               UserID = "002",
               UserName = "哈哈",
               Sex = "女"
           });
           listUser.Add(new User
           {
               UserID = "003",
               UserName = "嘿嘿",
               Sex = "男"
           });
           listUser.Add(new User
           {
               UserID = "004",
               UserName = "嘻嘻",
               Sex = "男"
           });
           #endregion

           string strUserName = Request["strUserName"];//查询条件
           var pageIndex = int.Parse(Request["page"]);//当前页
           var pageSize = int.Parse(Request["rows"]);//页面行数
           var total = 0;

           //首先得到符合该查询条件的总记录条数
           total = listUser.Where(p => p.UserName != strUserName).Count();

           //根据页号、页面大小和查询条件查询当前页应该显示的内容
           var listQuery = listUser.Where(p => p.UserName != strUserName)  //查询条件为：UserName不等于strUserName
                            .OrderBy(p => p.UserID)    //根据UserID进行升序排序
                            .Skip(pageSize * (pageIndex - 1))  //跳过记录中的前（pageSize * (pageIndex - 1)）行，假如当前页为第二页-pageIndex=2，每页显示10条数据-pageSize=10，那么就跳过记录中的前10条数据，达到分页查询的效果
                            .Take(pageSize);   //取出pageSize条记录

           var data = new
           {
               total,
               rows = listQuery
           };

           //将数据转换成Json格式
           JsonResult jsonUser = new JsonResult();
           jsonUser = Json(data);


           return jsonUser;
       }

        然后我们就可以看见结果：

                                                   

                                                 

        分页查询是一个很普通的东西，基本上只要有表格就需要分页查询，所以这些东西我们还是需要掌握。其中的拉姆达表达式，我们也可以在VS中通过F12转到定义，多看看其中方法的定义。