获取在asp.net MVC3的DropDownList数据的基础上名单 [英] Get list on basis of dropdownlist data in asp.net mvc3

问题描述

我有两个dropdownlists我的模块中。

在一个DropDownList中，我已经很难codeD中的所有像＆LT运营商;，＆GT;，＆LT; =，＆GT; =，==

在第二个DropDownList的，我的员工像辛勤codeD工资 1000,2000,3000,4000 .... 50000

现在，如果我选择＆LT; 从一个列表和 2000 从第二个列表，点击提交按钮我应该谁拿到的薪水有不到2000名员工的名单。

我想这样做在asp.net MVC3

我怎样才能完成这个任务？

我是否需要写存储过程呢？

谁能帮助我？

我创建的DropDownList这样的：

  viewModel.OperatorsList =新[]
                                {
                                 新SelectListItem {值=＆LT;文本=＆LT; }，
                                 新SelectListItem {值=＆gt;中，文本=＆gt;中}，
                                 新SelectListItem {值=＆LT; =文本=＆LT; =}，
                                 新SelectListItem {值=＆GT; =文本=＆GT; =}，
                                 新SelectListItem {值===，文本===}
                                                         };
   viewModel.SalaryList =新[]
                                                         {
                                 新SelectListItem {值=1000，文字=1000}，
                                 新SelectListItem {值=2000，文字=2000}，
                                 新SelectListItem {值=3000，文字=3000}，
                                 。
                                 。
                                  };
 

和我用它来显示视图中的DropDownList：

 ＆LT;％：Html.DropDownListFor（X =＆GT; x.Operators，Model.OperatorsList）％GT;
 

解决方案

好了，你可以做这样的事情。

假设视图模型 ...是你的视图模型，和你有一个实体员工与属性薪酬（ INT 在此示例中，它可能是一个小数在现实世界中）

创建一个静态辅助类

 公共静态类MyHelper
    {
        //一个字典操作员以及相应的防爆pressionType
        公共静态字典＆LT;字符串，防爆pressionType＆GT;防爆pressionTypeDictionary =新词典＆LT;字符串，防爆pressionType＆GT;
        {
            {＆LT;防爆pressionType.LessThan}，
            {＆gt;中，前pressionType.GreaterThan}，
            {＆GT; =，前pressionType.GreaterThanOrEqual}
            //等等
        };
        //过滤您可查询的方法
        公共静态的IQueryable＆LT;员工＆GT; FilterSalary（这IQueryable的＆LT;员工＆GT;可查询，INT工资，串operatorType）
        {
            恩pression的//左半部分：M
            变量参数=前pression.Parameter（typeof运算（员工），M）;
            //身体是前pression的右侧部分：M
            防爆pression体=参数;
            //m.Salary
            机身前= pression.Property（身体，工资）;
            //m.Salary＆所述; = 1000（例如）
            机身前= pression.MakeBinary（前pressionTypeDictionary [operatorType]，车身，前$​​ P $ pssion.Constant（工资））;
            // M =＆GT; m.Salary＆LT; = 1000
            VAR波长=前pression.Lambda＆LT;＆Func键LT;员工，布尔＆GT;＆GT;（身体，新的[] {参数}）;
            //所以这将是queryable.Where（M =＆GT; m.Salary＆下; = 1000）
            返回queryable.Where（拉姆达）;
        }
}
 

使用

  VAR可查询= context.All＆LT;员工＆GT;（）; //或类似的东西，并返回一个IQueryable＆LT;员工＆GT;
可查询= queryable.FilterSalary（viewModel.Salary，viewModel.Operators）;
 

I have two dropdownlists in my module.

In one dropdownlist, I have hardcoded all the operators like <,>,<=,>=,==

In second dropdownlist, I have hardcoded salary of employees like 1000,2000,3000,4000....50000

Now if I select < from one list and 2000 from second list and click on submit button I should get list of employees who have salary less than 2000.

I want to do this in asp.net mvc3

How can I accomplish this task???

Do I need to write stored procedure for this?

can anyone help me??

I have created dropdownlist like:

 viewModel.OperatorsList = new[]
                                {
                                 new SelectListItem { Value = "<", Text = "<" },
                                 new SelectListItem { Value = ">", Text = ">" },  
                                 new SelectListItem { Value = "<=", Text = "<=" },
                                 new SelectListItem { Value = ">=", Text = ">=" },
                                 new SelectListItem { Value = "==", Text = "==" }
                                                         };
   viewModel.SalaryList = new[]
                                                         {
                                 new SelectListItem { Value = "1000", Text = "1000" },
                                 new SelectListItem { Value = "2000", Text = "2000" },  
                                 new SelectListItem { Value = "3000", Text = "3000" },
                                 .
                                 .
                                  };

and I have used this to show dropdownlist in view:

 <%: Html.DropDownListFor(x => x.Operators, Model.OperatorsList)%>

解决方案

well, you could do something like that

assuming viewModel is... your viewModel, and you've got an entity Employee with a property Salary (int in this sample, it's probably a decimal in real world)

create a static helper class

public static class MyHelper
    {
        // a dictionary for your operators and corresponding ExpressionType
        public static Dictionary<string, ExpressionType> ExpressionTypeDictionary = new Dictionary<string, ExpressionType>
        {
            {"<", ExpressionType.LessThan},
            {">", ExpressionType.GreaterThan},
            {">=", ExpressionType.GreaterThanOrEqual}
            //etc
        };
        //a method to filter your queryable
        public static IQueryable<Employee> FilterSalary(this IQueryable<Employee> queryable, int salary, string operatorType)
        {
            //left part of the expression : m
            var parameter = Expression.Parameter(typeof(Employee), "m");
            //body is the right part of the expression : m
            Expression body = parameter;
            //m.Salary
            body = Expression.Property(body, "Salary");
            //m.Salary <= 1000 (for example)
            body = Expression.MakeBinary(ExpressionTypeDictionary[operatorType], body, Expression.Constant(salary));
            //m => m.Salary <=1000
            var lambda = Expression.Lambda<Func<Employee, bool>>(body, new[] { parameter });
            //so it will be queryable.Where(m => m.Salary <= 1000)
            return queryable.Where(lambda);
        }
}

usage

var queryable = context.All<Employee>();//or something like that, returning an IQueryable<Employee>
queryable = queryable.FilterSalary(viewModel.Salary, viewModel.Operators);

这篇关于获取在asp.net MVC3的DropDownList数据的基础上名单的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！