var selectedItems = from item in items
　　　　　　　　　　　　where item.ParentID == parentID
　　　　　　　　　　　　orderby item.SortIndex descending ,item.Name ascendingselect item;

var list=collection.Where(t => (txtCustomerName.Text.Trim().Length == 0 || t.ClientName.ToUpper().IndexOf(txtCustomerName.Text.Trim().ToUpper()) >= 0)); 

string[] words = { "the", "quick", "brown", "fox", "jumps" };
IEnumerable<string> query = from word in words where word.Length == 3
 　　　　　　　　　　　　　　　　select word;

bool anyUSA=customers.Any(c=>c.Country=="USA") //如果对于列表中的任意顾客，λ表达式是true，就返回true
bool allAsia=customers.All(c=>c.Region=="Asia") //列表中的所有顾客来自亚洲，返回true。

private BuildExpression(IEnumberable<string>enumberableList){...} //定义 function      return factory =>{BuildExpression(factory); //递归实现的function};

var listFlowActions = new List<FlowAction>();
var connectors = flowActions.Where(i => i.ActionType == MongoConstants.FlowActions.Connector && IsFlowActionExists(i.SourceFlowActionId)&& IsFlowActionExists(i.TargetFlowActionId)).OrderBy(connection => connection.Index);
var allNodes = flowActions.Where(i => i.ActionType != MongoConstants.FlowActions.Connector);
var connectedNodes = new List<FlowAction>();
connectors.Each(t => connectedNodes.Add(allNodes.Where(i => i.Id == t.SourceFlowActionId).FirstOrDefault())).Each(t=>connectedNodes.Add(allNodes.Where(i=>i.Id==t.TargetFlowActionId).FirstOrDefault()));
var notConnectedNodes = connectedNodes.Except(connectedNodes) .Each((i, index) => i.X = index * 100).Each(i => i.Y = 50);;

     public static bool SaveEmployeeToFunctionPoint(Guid functionPointID, List<Guid> employeeIDList){var oldCollection = new EmployeeToFunctionPointCollection();oldCollection.GetMulti(EmployeeToFunctionPointFields.FunctionPointId == functionPointID);var oldIDList = from item in oldCollection select item.EmployeeId; var newList = from item in employeeIDList where !oldIDList.Contains(item) selectitem; //选择 employeeidlist中不与oldidlist中重复的项var trans = new Transaction(System.Data.IsolationLevel.ReadCommitted, "SaveEmployeeToFunctionPoint");try{foreach (Guid empID in newList){                    var entity = new EmployeeToFunctionPointEntity{EmployeeId = empID,FunctionPointId = functionPointID,IsMain = false}; trans.Add(entity); entity.Save(); } trans.Commit();return true; } catch (Exception e){trans.Rollback();return false;}}

static void FunLinq(){int[] numbers = { 2, 10, 30, 15, 1, 22 };//输出大于10的总数int count = (from i in numbers where i > 10 orderby i select i).Count<int>();Console.WriteLine(count);//输出：3}

      var newnumbers = from i in numbers select i;foreach (var p in numbers.Reverse()){Console.WriteLine(p);//输出22 1 15 30 10 2}

//排序(正序)string[] games = { "Morrowind", "Uncharted 2", "Fallout 3", "Daxter", "Shock2" };var newn = from i in games orderby i ascending select i;foreach (var p in games){Console.Write(p+",");//
            } 

var queryResult= from c in customersOrderby c.Region,c.Country,c.CitySelect new(c.ID,c.Region,c.County,C.City)

var queryResult=customers.OrderBy(c=>c.Region).ThenByDescending(c=>c.County).ThenBy(c=>c.City).select(c=>new{c.ID,c.Region,c.Country,c.City})

//排序(正序)string[] games = { "Morrowind", "Uncharted 2", "Fallout 3", "Daxter", "Shock2", "Shock2"};var newn = from i in games orderby i ascending select i;foreach (var p in games.Disinct()){Console.Write(p+",");//
            }

//聚合操作//最大值var maxi =( from i in games orderby i ascending select i).Max();//最小值var mini = (from i in games orderby i ascending select i).Min();//平均值var avar = (from i in numbers orderby i ascending select i).Average();//总和var sum = (from i in numbers orderby i ascending select i).Sum();list.Sum(item=>item.Quantity);    //合计，合计list中的quantity 字段querResults.Sum(n=>(long)n)   //无参数返回32位int类型，n=>(long)n转化为64位，防止溢出

string sentence = "the quick brown fox jumps over the lazy dog";// Split the string into individual words.string[] words = sentence.Split(' ');// Prepend each word to the beginning of the // new sentence to reverse the word order.string reversed = words.Aggregate((workingSentence, next) =>next + " " + workingSentence);outputBlock.Text += reversed + "\n";// This code produces the following output: dog lazy the over jumps fox brown quick the 

List<string> words = new List<string>() { "an", "apple", "a", "day" };
var query = from word in wordsselect word.Substring(0, 1);

List<string> phrases = new List<string>() { "an apple a day", "the quick brown fox" };
var query = from phrase in phrasesfrom word in phrase.Split(' ')select word;
var queryResult= from c in customers Where c.Region=="North America"Select new(c.City,c.Count,c.Sales)
var queryResult=customers.where(c=>c.Region=="North America").select(c=>new(c.City,c.Count,c.Sales))

string[] words = { "an", "apple", "a", "day", "keeps", "the", "doctor", "away" };
var query = words.Skip(4);

string[] words = { "an", "apple", "a", "day", "keeps", "the", "doctor", "away" };
var query = words.SkipWhile(u => u.Substring(0, 1) == "a");

string[] words = { "an", "apple", "a", "day", "keeps", "the", "doctor", "away" };
var query = words.Take(2);

string[] words = { "an", "apple", "a", "day", "keeps", "the", "doctor", "away" };
var query = words.TakeWhile(u => u.Length < 6);

dbconn.BidRecord.OrderBy(p=>p.bid_id).ToList<BidRecord>().OrderBy(p => p.bid_id).Skip(skip).Take(take).ToList<BidRecord>();

var queryResult= from c in customerGroup c by c.Region in to cgSelect new(TotalSales=cg.Sum(c=>c.Sales),Region=cg.Key)