Lambda,MVC 练习（20101117)

   复习以前学过的东西 发现大部分东西都忘记了。悲剧。后来总结发现应该记个记号，以后没事的时候翻出来瞅两眼，忘的就不是那么快了。那都是必须的。

   摘至MSDN ：Lambda

 

1、“Lambda 表达式”是一个并匿名函数，它可以包含表达式和语句，且可用于创建委托或表达式树类型。

所有 Lambda 表达式都使用 Lambda 运算符=>。 该运算符读为“goes to”。 该 Lambda 运算符的左边是输入参数（如果有），右边包含表达式或语句块。 Lambda 表达式 x => x * x 读作“x goes to x times x”。可以将此表达式分配给委托类型.

 

2、=> 运算符具有与赋值运算符 (=) 相同的优先级，并且是右结合运算符。

lambda=>Msdn.lambdaInfo.

 

  1、建立一个MVC工程.

 2、建立以个文件夹并命名为components与Views文件夹同级.

    其次在components下建立类Mycompares其代码如下:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Collections;

namespace LambdaMvcPractice.Components
{
    public class Mycompare : IComparer<int>
    {
        public int Compare(int x, int y)
        {
            int x1 = Math.Abs(x);
            int y1 = Math.Abs(y);
            if (x1 > y1)
            {
                return 1;
            }
            else if (x1 == y1)
            {
                return 0;
            }
            else
            {
                return -1;
            }
        }
    }
}

 3、LambdaController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Collections;

namespace LambdaMvcPractice.Controllers
{
    public class LambdaController : Controller
    {
        //
        // GET: /Lambda/

        int[] Age = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
        //1、Where()
        public ActionResult Where()
        {
            //声明一数组
            //通过Where来过滤 能被2整除的数
            ViewData["NewAgeList"] = Age.Where(n => n % 2 == 0);
            ViewData["NewAgeListByIndex"] = Age.Where((num, index) => num >= index * 2);
            return View();
        }

        //2、OrderBy()
        public ActionResult OrderBy()
        {

            int[] C = { 1, -2, 3, -4, 5, -6, 7, -8, 9, -10 };
            //除10后升序排列
            ViewData["OrderByAsc"] = Age.OrderBy(M => M % 10);
            //除10后降序排列
            ViewData["OrderByDes"] = Age.OrderByDescending(M => M % 10);
            //通过Mycompare类中的compare方法来进行升序排列
            ViewData["CompareList"] = C.OrderBy(M => M, new Components.Mycompare());
            return View();
        }

        //3、Skip
        public ActionResult Skip()
        {
            //int[] Age = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
            //跳过前3个元素
            ViewData["SkipList"] = Age.Skip(3);
            //跳出小于7的元素
            ViewData["SkipWhile"] = Age.SkipWhile(M => M < 7);
            return View();
        }
        //4、Take
        public ActionResult Take()
        {
            int[] A = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
            //提取前9个元素,在跳出前小于4的元素，在取出小于7的元素.(如果这里lambda表达式为:M=>M>7,显示不出数据(越界))
            ViewData["TakeList"] = A.Take(9).SkipWhile(M => M < 4).TakeWhile(M => M < 7);
            //提取小于5的元素跳出前3个元素..
            ViewData["TakeWhile"] = A.TakeWhile(M => M <= 5).Skip(3);
            //不支持自动排序,不支持M>2&&M<5?,不支持M==5?.
            return View();
        }

        //5、Min Max Avg Sum
        public ActionResult Func()
        {
            IList<string> Fuclist = new List<string>();
            //最小值
            Fuclist.Add(Age.Min().ToString());
            //最大值
            Fuclist.Add(Age.Max().ToString());
            //平均值
            Fuclist.Add(Age.Average().ToString());
            //求和
            Fuclist.Add(Age.Sum().ToString());
            ViewData["Fuc"] = Fuclist;

            int[] intary = { 1, 1, 2, 2, 3, 3, 4, 5 };
            //过滤相同字符串
            ViewData["Distinct"] = intary.Distinct();
            return View();
        }

        public ActionResult Concat()
        {
            string[] strAry1 = { "Kevin", "James", "Ben" };
            string[] strAry2 = { "Ken", "James", "cc" };
            //左连右
            ViewData["Concat1"] = strAry1.Concat(strAry2);
            //右连左
            ViewData["Concat2"] = strAry2.Concat(strAry1);
            //并集
            ViewData["Union"] = strAry1.Union(strAry2);
            //交集
            ViewData["Intersect"] = strAry1.Intersect(strAry2);
            //差集
            ViewData["Except"] = strAry1.Except(strAry2);
            return View();
        }


    }
}

 前台Views只贴几个页面。觉得写的不是很好。如果有朋友些的好的可以指出，我好改正。

Where:

<%@ Page Title="" Language="C#" Debug="true" MasterPageFile="~/Views/Shared/Site.Master"
    Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Index
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <h2>
        Where()<br />
        数组Arrylist={1,2,3,4,5,6,7,8,9,10}<br />
        --------------Begin--------------<br />
        被2整除的数<br />
        结果：
        <% IList<int> Arrylist = (ViewData["NewAgeList"] as IEnumerable<int>).ToList<int>(); %>
        <%= Html.Display("<br/>") %>
        <% for (int i = 0; i < Arrylist.Count; i++) %>
        <% { %>
        <%= Html.Label(Arrylist[i].ToString()) %>
        <% } %>
        <br />
        ------------------------------<br />
        本身大于2倍索引<br />
        结果：
        <% IList<int> Arrylist2 = (ViewData["NewAgeListByIndex"] as IEnumerable<int>).ToList<int>(); %>
        <% for (int j = 0; j < Arrylist2.Count; j++) %>
        <% { %>
        <%= Html.Label(Arrylist2[j].ToString())%>
        <% } %><br />
        ---------------End---------------
    </h2>
</asp:Content>

 

 

 

 

Concat

<%@ Page Title="" Language="C#" Debug="true" MasterPageFile="~/Views/Shared/Site.Master"
    Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Concat
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <h2>
        Concat()<br />
        数组strAry1 = { "Kevin", "James", "Ben" }<br />
        strAry2 = { "Ken", "James", "cc" }<br />
        --------------Begin--------------<br />
        strAry1连strAry2<br />
        结果：
        <% IList<string> Arrylist = (ViewData["Concat1"] as IEnumerable<string>).ToList<string>(); %>
        <% for (int i = 0; i < Arrylist.Count; i++) %>
        <% { %>
        <%= Html.Label(Arrylist[i].ToString()) %>
        <% } %>
        <br />
        ------------------------------<br />
        strAry2连strAry1<br />
        结果：
        <% IList<string> Arrylist2 = (ViewData["Concat2"] as IEnumerable<string>).ToList<string>(); %>
        <% for (int j = 0; j < Arrylist2.Count; j++) %>
        <% { %>
        <%= Html.Label(Arrylist2[j].ToString())%>
        <% } %><br />
        ------------------------------<br />
        并集<br />
        结果：
        <% IList<string> Arrylist3 = (ViewData["Union"] as IEnumerable<string>).ToList<string>(); %>
        <% for (int k = 0; k < Arrylist3.Count; k++) %>
        <% { %>
        <%= Html.Label(Arrylist3[k].ToString())%>
        <% } %><br />
        ------------------------------<br />
        交集<br />
        结果：
        <% IList<string> Arrylist4 = (ViewData["Intersect"] as IEnumerable<string>).ToList<string>(); %>
        <% for (int l = 0; l < Arrylist4.Count; l++) %>
        <% { %>
        <%= Html.Label(Arrylist4[l].ToString())%>
        <% } %><br />
        ------------------------------<br />
        差集<br />
        结果：
        <% IList<string> Arrylist5 = (ViewData["Except"] as IEnumerable<string>).ToList<string>(); %>
        <% for (int m = 0; m < Arrylist5.Count; m++) %>
        <% { %>
        <%= Html.Label(Arrylist5[m].ToString())%>
        <% } %><br />
        ---------------End---------------</h2>
</asp:Content>

 

OrderBy

 

<%@ Page Title="" Language="C#" Debug="true" MasterPageFile="~/Views/Shared/Site.Master"
    Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    OrderBy
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <h2>
        Order()<br />
        数组:Arrylist={1,2,3,4,5,6,7,8,9,10}
        <br />
        ------------Begin------------<br />
        升序<br />
        结果：<% IList<int> Arrlist = (ViewData["OrderByAsc"] as IEnumerable<int>).ToList<int>(); %>
        <% for (int i = 0; i < Arrlist.Count; i++) %>
        <% { %>
        <%= Html.Label(Arrlist[i].ToString())%>
        <% } %>
        <br />
        ---------------------------
        <br />
        降序<br />
        结果： <% IList<int> Arrlist2 = (ViewData["OrderByDes"] as IEnumerable<int>).ToList<int>(); %>
        <% for (int j = 0; j < Arrlist2.Count; j++) %>
        <% { %>
        <%= Html.Label(Arrlist2[j].ToString())%>
        <% } %>
        <br />
        ---------------------------
        <br />
        自定义方法升序<br />
        数组:Arrylist={1,-2,3,-4,5,-6,7,-8,9,-10}<br />
        <% IList<int> Arrlist3 = (ViewData["CompareList"] as IEnumerable<int>).ToList<int>(); %>
        <% for (int k = 0; k < Arrlist3.Count; k++) %>
        <% { %>
        <%= Html.Label(Arrlist3[k].ToString())%>
        <% } %>
         <br />
        ------------End------------       
    </h2>
</asp:Content>

Skip

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Skip
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <h2> Skip()、SkipWhile()<br />
        数组Arrylist={1,2,3,4,5,6,7,8,9,10}<br />
        --------------Begin--------------<br />
        提取前9个元素,在跳出前小于4的元素，在取出小于5的元素.(如果这里lambda表达式为:M=>M>7,显示不出数据(越界))<br />
        结果：<% IList<int> Arrylist = (ViewData["SkipList"] as IEnumerable<int>).ToList<int>(); %>
        <%= Html.Display("<br/>") %>
        <% for (int i = 0; i < Arrylist.Count; i++) %>
        <% { %>
        <%= Html.Label(Arrylist[i].ToString()) %>
        <% } %>
        <br />
        ------------------------------<br />
        跳过小于7的元素<br />
       结果： <% IList<int> Arrylist2 = (ViewData["SkipWhile"] as IEnumerable<int>).ToList<int>(); %>
        <% for (int j = 0; j < Arrylist2.Count; j++) %>
        <% { %>
        <%= Html.Label(Arrylist2[j].ToString())%>
        <% } %><br />
        ---------------End---------------</h2>

</asp:Content>

 Take.aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Take
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <h2>Take()、TakeWhile()<br />
        数组Arrylist={11, 12, 13, 14, 5, 6, 7, 8, 9, 10 }<br />
        --------------Begin--------------<br />
        提取前9个元素,在跳出前小于4的元素，在取出小于7的元素.<br />
        (如果这里lambda表达式为:M=>M>7,显示不出数据(越界))<br />
        结果：
        <% IList<int> Arrylist = (ViewData["TakeList"] as IEnumerable<int>).ToList<int>(); %>
        <%= Html.Display("<br/>") %>
        <% for (int i = 0; i < Arrylist.Count; i++) %>
        <% { %>
        <%= Html.Label(Arrylist[i].ToString()) %>
        <% } %>
        <br />
        ------------------------------------------------------------<br />
        提取小于5的元素跳出前3个元素..<br />
        结果：
        <% IList<int> Arrylist2 = (ViewData["TakeWhile"] as IEnumerable<int>).ToList<int>(); %>
        <% for (int j = 0; j < Arrylist2.Count; j++) %>
        <% { %>
        <%= Html.Label(Arrylist2[j].ToString())%>
        <% } %><br />
        ---------------End---------------</h2>

</asp:Content>

 

 Func.aspx

<%@ Page Title="" Debug="true" Language="C#" MasterPageFile="~/Views/Shared/Site.Master"
    Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Func
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <h2>
        Func()：Min,Max,Avg,Sum<br />
        数组Arrylist={1,2,3,4,5,6,7,8,9,10}<br />
        --------------Begin--------------<br />
        结果：
        <% IList<string> Arrylist = ViewData["Fuc"] as List<string>; %>
        <%= Html.Display("<br/>") %>
        <% for (int i = 0; i < Arrylist.Count; i++) %>
        <% { %>
        <%= Html.Label(Arrylist[i].ToString()) %>
        <% } %>
        <br />
        ---------------End---------------</h2>
    <h2>
        Distinct() 数组Arrylist={1,1, 2,2, 3, 3, 4, 5}<br />
        --------------Begin--------------<br />
        结果：
        <% IList<int> Arrylist2 = (ViewData["Distinct"] as IEnumerable<int>).ToList<int>(); %>
        <% for (int j = 0; j < Arrylist2.Count; j++) %>
        <% { %>
        <%= Html.Label(Arrylist2[j].ToString()) %>
        <% } %>
        <br />
        ---------------End---------------</h2>
</asp:Content>

 

 

 

  That's all.

希望各位园友指点指点。有各位的指点，才会不断进步.

 

VS2008+SP1

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