publicstaticvoidMain(string[] args){ varlist= new List<int>() {10,20,30,40,50,60,70,80,90,100,110,120, }; var rateList =list.Select((item, index) => {returnindex ==0?0: Math.Round(((decimal)list[index] -list[index -1]) /list[index -1],2); }).ToList(); rateList....
};varselectResult =fromsinstudentListselects.StudentName; select可以定义结果数据类型,可以返回用户自定义的类型或者匿名类型 IList<Student> studentList =newList<Student>() {newStudent() { StudentID =1, StudentName ="John", Age =13} ,newStudent() { StudentID =2, StudentName ="Moin", Age =...
select new { c.VideoNetServerRowID,c.VedeoNetServerName,c.VedeoNetServerCode,c.IPAddress,cc.AreaName };return query;} public static List<Plant> GetData { get{ var ds = DataAccess.VideoNetServers.SelectAnyInfo();List<Plant> data = new List<Plant>();foreach (var obj in ds){ //这个...
().Select(x => x.WellID).ToList(); WellOrganDescriptor类封装了组织机构单井信息类,利用ofType方法限定了方法属性名,通过select方法投影出单井的ID属性,使用var匿名定义方法返回值。 单属性投影 select多属性投影 多属性投影相比单属性投影多了定义一个new的步骤,分为两种情况,一种是new出当前list的单个属性...
vartoCityList=fromaindb.CR_BC_CITYjoinbindb.CR_BE_TAILWIND_CAR_RENTALona.CR_BC_CITY_ID equals b.CR_BC_CITY_IDselecta;varhumpPinyinsList=fromainfromCityListjoinbintoCityListona.CR_BC_CITY_ID equals b.CR_BC_CITY_IDselectnew{a.HUMP_PINYINS};foreach(varvinhumpPinyinsList){//这里用到了...
C# Select .CSV File, Read Into MS Access Database C# Send Data To Various Computer C# Send mouseclick to hWnd C# SendKeys.Send problem C# serialize list<string> to xml C# Serialize to JSON inside a text file, but the object is empty, why? C# Server - TcpClient.Client.Receive - Is ...
var estimateModel = new EstimateModel() { ShopID = 1, YearCrowdFilterDict = new Dictionary<string, List<TagCrowdFilterModel>>() { { "17年",new List<TagCrowdFilterModel>() { new TagCrowdFilterModel(){ CrowdFiter="between 10 and 20" }, ...
查询子句本身可能包含查询表达式,也称为子查询。每个子查询都是以from子句开头,该子句不一定指向第一个from子句中相同的数据源。如下示例中,在select语句用于检索分组操作结果的查询表达式。 var groupMax = from city in cityList group city by city.Population into newCity select new { Level = newCity.Key,...
List<int> numbers = [1,2,4,6,8,10,12,14,16,18,20]; IEnumerable<int> queryFactorsOfFour =fromnuminnumberswherenum %4==0selectnum;// Store the results in a new variable// without executing a foreach loop.varfactorsofFourList = queryFactorsOfFour.ToList();// Read and write from ...
List<int> numbers = [1,2,4,6,8,10,12,14,16,18,20]; IEnumerable<int> queryFactorsOfFour =fromnuminnumberswherenum %4==0selectnum;// Store the results in a new variable// without executing a foreach loop.varfactorsofFourList = queryFactorsOfFour.ToList();// Read and write from ...