var multiColQuery = from line in strs let elements = line.Split(',') let scores = elements.Skip(1) select (from str in scores select Convert.ToInt32(str)); // Execute the query and cache the results to improve // performance. // ToArray could be used instead of ToL...
stringstartFolder ="""C:\Program Files\dotnet\sdk""";// Or// string startFolder = "/usr/local/share/dotnet/sdk";varfileList = Directory.GetFiles(startFolder,"*.*", SearchOption.AllDirectories);varfileQuery =fromfileinfileListletfileLen =newFileInfo(file).LengthwherefileLen >0s...
var result = (from d1 in dataset1 join d2 in dataset2 on d1.Key equals d2.Key where d1.SomeProperty == "SomeValue" select new { d1, OtherProperty = d2.OtherProperty }).ToList(); 说明:虽然方法语法通常更简洁,但查询语法可以增强可读性,尤其是对于涉及联接、where 和 select 语句的...
static void SelectVsSelectMany() { List<Bouquet> bouquets = new List<Bouquet>() { new Bouquet { Flowers = new List<string> { "sunflower", "daisy", "daffodil", "larkspur" }}, new Bouquet{ Flowers = new List<string> { "tulip", "rose", "orchid" }}, new Bouquet{ Flowers = new ...
Array' does not contain a definition for 'Select' and no extension method 'Select' accepting a first argument of type 'System.Array' could be found (are you missing a using directive or an assembly reference?) C# Console App - Can't retrieve SOAP 1.2 response from Web Service C# Console...
由原型可看到它将原本的集合视为TOuter,而将传入的集合视为TInner,儿还要决定由哪个属性或成员当Key,最后由resultSelector来输出联接的结果。例: 1var query=from item1inlist12 join item2inlist2 on item1 equals item23selectitem2;4var query3=list1.Join(5list2,6 item1=>item1,7 item2=>item2,8...
所选子集合中的字段可以是静态的,但是我希望动态地传递当前实体中的字段列表,以及导航属性引用的其他实体中的字段。下面是查询的静态版本,类似于我在代码中使用的查询,在很多地方,我想动态地创建这个查询: var listItems = _efDbContext.Blogs.Select(x => new {Ivan的答案确实很酷,但它不支持引...
Select用法varselectedItems =fromiteminitemswhereitem.ParentID == parentIDorderbyitem.SortIndex descending ,item.Name ascendingselectitem;0.1where:varlist=collection.Where(t => (txtCustomerName.Text.Trim().Length ==0|| t.ClientName.ToUpper().IndexOf(txtCustomerName.Text.Trim().ToUpper()) >=0...
() where c.active select c).ToList();/*C#写法3*/IEnumerable JointList = ( from r1 in list...( inner: salaryList, /*因为比较器用到了name和occupation两个属性,所以这里的Selector要包含这两个有用的属性值...在数据库或其他数据源操作中,Join操作使得从多个表中组合数据变得可能,极...
' Returns a combined collection of all of the' processes currently running and a descriptive' name for the process taken from a list of' descriptive names.Dimprocesses =FromprocInProcess.GetProcessesJoindescInprocessDescriptionsOnproc.ProcessNameEqualsdesc.ProcessNameSelectproc.ProcessName, proc.Id, ...