VS 2008 + .NET 3.5 - LINQ查询操作符(二)_silverlight

VS 2008 + .NET 3.5 - LINQ查询操作符之DisTinct、Union、Concat、Intersect、Except、Skip、Take、SkipWhile、TakeWhile、Single、SingLeorDefault、Reverse、SELEctMany

介绍
    ·DisTinct - 过滤集合中的相同项；延迟
    ·Union - 连接不同集合，自动过滤相同项；延迟
    ·Concat - 连接不同集合，不会自动过滤相同项；延迟
    ·Intersect - 获取不同集合的相同项（交集）；延迟
    ·Except - 从某集合中删除其与另一个集合中相同的项；延迟
    ·Skip - 跳过集合的前n个元素；延迟
    ·Take - 获取集合的前n个元素；延迟
    ·SkipWhile - 直到某一条件成立就停止跳过；延迟
    ·TakeWhile - 直到某一条件成立就停止获取；延迟
    ·Single - 根据表达式返回集合中的某一元素；不延迟
    ·SingLeorDefault - 根据表达式返回集合中的某一元素（如果没有则返回默认值）；不延迟
    ·Reverse - 对集合反向排序；延迟
    ·SELEctMany - SELEct选择（一对多）；延迟

示例

SumMary2.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml.Linq;

using System.Collections.Generic;
using DAL;

public partial class LINQ_SumMary2 : System.Web.UI.Page
{
northwindDataContext _ctx = new NorthwindDataContext();
String[] _ary = null;

    protected void Page_Load(object sender,EventArgs E)
    {
        _ary = new String[] { "asp.net","csharp","xhtml","css","javascript","wcf","wpf",
            "asp.net",
            "silverlight","linq","wf","sqlserver","asp.net ajax","ssis","ssas","ssrs" };

// DisTinct - 过滤集合中的相同项；延迟
SumMary_DisTinct();

// Union - 连接不同集合，自动过滤相同项；延迟
SumMary_Union();

// Concat - 连接不同集合，不会自动过滤相同项；延迟
SumMary_Concat();

// Intersect - 获取不同集合的相同项（交集）；延迟
SumMary_Intersect();

// Except - 从某集合中删除其与另一个集合中相同的项；延迟
SumMary_Except();

        // Skip - 跳过集合的前n个元素；延迟
        // Take - 获取集合的前n个元素；延迟
        SumMary_Skip_Take();

        // SkipWhile - 直到某一条件成立就停止跳过；延迟
        // TakeWhile - 直到某一条件成立就停止获取；延迟
        SumMary_SkipWhile_TakeWhile();

        // Single - 根据表达式返回集合中的某一元素；不延迟
        // SingLeorDefault - 根据表达式返回集合中的某一元素（如果没有则返回默认值）；不延迟
        SumMary_Single_SingLeorDefault();

// Reverse - 对集合反向排序；延迟
SumMary_Reverse();

        // SELEctMany - SELEct选择（一对多）；延迟
        SumMary_SELEctMany();
    }
}

DisTinct - 过滤集合中的相同项；延迟

//// <sumMary>
 /// DisTinct - 过滤集合中的相同项；延迟
 /// </sumMary>
 void SumMary_DisTinct()
 {
 var ary = (from a in _ary
 SELEct a).DisTinct();

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }
运行结果
asp.net
csharp
xhtml
css
javascript
wcf
wpf
silverlight
linq
wf
sqlserver
asp.net ajax
ssis
ssas
ssrs

Union - 连接不同集合，自动过滤相同项；延迟

//// <sumMary>
 /// Union - 连接不同集合，自动过滤相同项；延迟
 /// </sumMary>
 void SumMary_Union()
 {
 var ary = (from a in _ary
 SELEct a).Take(3).Union((from a in _ary
 SELEct a).Take(6));

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }

运行结果
asp.net
csharp
xhtml
css
javascript
wcf

Concat - 连接不同集合，不会自动过滤相同项；延迟

//// <sumMary>
 /// Concat - 连接不同集合，不会自动过滤相同项；延迟
 /// </sumMary>
 void SumMary_Concat()
 {
 var ary = (from a in _ary
 SELEct a).Take(3).Concat((from a in _ary
 SELEct a).Take(6));

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }

运行结果
asp.net
csharp
xhtml
asp.net
csharp
xhtml
css
javascript
wcf

Intersect - 获取不同集合的相同项（交集）；延迟

//// <sumMary>
 /// Intersect - 获取不同集合的相同项（交集）；延迟
 /// </sumMary>
 void SumMary_Intersect()
 {
 var ary = (from a in _ary
 SELEct a).Take(3).Intersect((from a in _ary
 SELEct a).Skip(1).Take(3));

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }

运行结果
csharp
xhtml

Except - 从某集合中删除其与另一个集合中相同的项；延迟

//// <sumMary>
 /// Except - 从某集合中删除其与另一个集合中相同的项；延迟
 /// </sumMary>
 void SumMary_Except()
 {
 var ary = (from a in _ary
 SELEct a).Take(3).Except((from a in _ary
 SELEct a).Skip(1).Take(3));

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }

运行结果
asp.net

Skip - 跳过集合的前n个元素；延迟
Take - 获取集合的前n个元素；延迟

//// <sumMary>
 /// Skip - 跳过集合的前n个元素；延迟
 /// Take - 获取集合的前n个元素；延迟
 /// </sumMary>
 void SumMary_Skip_Take()
 {
 var ary = (from a in _ary
 SELEct a).Skip(2).Take(3);

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }

运行结果
xhtml
css
javascript

SkipWhile - 直到某一条件成立就停止跳过；延迟
TakeWhile - 直到某一条件成立就停止获取；延迟

//// <sumMary>
 /// SkipWhile - 直到某一条件成立就停止跳过；延迟
 /// TakeWhile - 直到某一条件成立就停止获取；延迟
 /// </sumMary>
 void SumMary_SkipWhile_TakeWhile()
 {
 var ary = (from a in _ary
 SELEct a).SkipWhile(s => s.Length < 8).TakeWhile(s => s.Length > 2);

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }

运行结果
javascript
wcf
wpf
asp.net
csharp
xhtml
css
javascript
silverlight
linq

Single - 根据表达式返回集合中的某一元素；不延迟
SingLeorDefault - 根据表达式返回集合中的某一元素（如果没有则返回默认值）；不延迟

//// <sumMary>
 /// Single - 根据表达式返回集合中的某一元素；不延迟
 /// SingLeorDefault - 根据表达式返回集合中的某一元素（如果没有则返回默认值）；不延迟
 /// </sumMary>
 void SumMary_Single_SingLeorDefault()
 {
 String s = (from a in _ary
 SELEct a).Single(a => a == "silverlight");
 // String s = (from a in _ary
 // SELEct a).SingLeorDefault(a => a == "xxx");
 // s == null

result.InnerHtml += s + " ";
 result.InnerHtml += " ";
 }

运行结果
silverlight

Reverse - 对集合反向排序；延迟

//// <sumMary>
 /// Reverse - 对集合反向排序；延迟
 /// </sumMary>
 void SumMary_Reverse()
 {
 var ary = (from a in _ary
 orderby a.Length ascending
 SELEct a).Reverse();

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }

运行结果
asp.net ajax
silverlight
javascript
javascript
sqlserver
asp.net
asp.net
csharp
csharp
xhtml
xhtml
ssrs
ssas
ssis
linq
css
wpf
wcf
css
wf

SELEctMany - SELEct选择（一对多）；延迟

//// <sumMary>
 /// SELEctMany - SELEct选择（一对多）；延迟
 /// </sumMary>
 void SumMary_SELEctMany()
 {
 var ary = (from a in _ary
 where a.Contains(".")
 SELEct a).SELEctMany(a => a.Split('.'));

foreach (String s in ary)
 {
 result.InnerHtml += s + " ";
 }
 result.InnerHtml += " ";
 }

运行结果aspnetaspnetaspnet ajax

VS 2008 + .NET 3.5 - LINQ查询操作符(二)

概述

大佬总结