Displaying processDate from dataItem2 does not require LINQ… Just user standard dot notation. If this does not answer your question please post the relevant code. Proper way: dataItem2.ProcessDate On the other hand if you have a collection of DataItem objects like below: List<DataItem> items = PopulateMyItems(); then you can filter like so: items.Where(t=>t.ProcessDate > TwoWeeksAgo); … Read more
Here’s how I’d go about it – I wrote it in SQL because I’m WAY better at that than I am at LINQ, but converting from one to the other should be straightforward: select t1.id , t1.value from table1 as t1 inner join table2 as t21 on t21.idTable1 = t1.id and t21.number = 1 inner … Read more
You can use LINQ: int updateInt = 0; var mostRecendUpdate = Directory.EnumerateDirectories(updateDir) .Select(path => new { fullPath = path, directoryName = System.IO.Path.GetFileName(path) // returns f.e. Update15 }) .Where(x => x.directoryName.StartsWith(“Update”)) // precheck .Select(x => new { x.fullPath, x.directoryName, updStr = x.directoryName.Substring(“Update”.Length) // returns f.e. “15” }) .Where(x => int.TryParse(x.updStr, out updateInt)) // int-check and initialization … Read more
Either LINQ: List<Guid> guids = guidStrings.Select(Guid.Parse).ToList(); or List.ConvertAll which is a little bit more efficient because it knows the size: List<Guid> guids = guidStrings.ConvertAll(Guid.Parse); 0 solved Convert a Collection of Strings into Collection of GUID
I would use a HashSet<string> in this case: var files = new HashSet<string> { “file0”, “file1”, “file2”, “file3” }; string originalFile = “file0″; string file = originalFile; int counter = 0; while (!files.Add(file)) { file = $”{originalFile}({++counter})”; } If you have to use a list and the result should also be one, you can still … Read more
You can write your own extension method that works like the built-in LINQ methods: public static class Extensions { public static IEnumerable<T> DistinctWhere<T>(this IEnumerable<T> input, Func<T,bool> predicate) { HashSet<T> hashset = new HashSet<T>(); foreach(T item in input) { if(!predicate(item)) { yield return item; continue; } if(!hashset.Contains(item)) { hashset.Add(item); yield return item; } } } } … Read more
Type of conditional expression cannot be determined because there is no implicit conversion between ‘Entities.KRAParameterInfo’ and ‘string’ solved Type of conditional expression cannot be determined because there is no implicit conversion between ‘Entities.KRAParameterInfo’ and ‘string’
Yes, you can simply use multiple from clauses: var result = from x in list1 from y in list2 from z in list3 select x+y+z; In the csharp interactive shell, this gives: csharp> var list1 = new string[] {“A”, “B”, “C”}; csharp> var list2 = new string[] {“1”, “2”, “3”}; csharp> var list3 = new … Read more
I solved the problem. Actually the problem was I didn’t have a using directive to System.Data.Entity namespace at the top of my class. Even thought I could use “Include(“PropertyName)” name in my query, I couldn’t use “Include(x=> x.Childs)”. But after adding “using System.Data.Entity” on top of my class I can use “Include” in these both … Read more
Check the reference source from Microsoft here Following is the SelectMany overload being utilized public static IEnumerable<TResult> SelectMany<TSource, TCollection, TResult>(this IEnumerable<TSource> source, Func<TSource, IEnumerable<TCollection>> collectionSelector, Func<TSource, TCollection, TResult> resultSelector) { if (source == null) throw Error.ArgumentNull(“source”); if (collectionSelector == null) throw Error.ArgumentNull(“collectionSelector”); if (resultSelector == null) throw Error.ArgumentNull(“resultSelector”); return SelectManyIterator<TSource, TCollection, TResult>(source, collectionSelector, resultSelector); } … Read more
bool contains = list.Any(yourString.Contains); This is searching for substrings, so it doesn’t compare “words”. Here is a version that ignores the case: bool contains = list.Any(s => yourString.IndexOf(s, StringComparison.CurrentCultureIgnoreCase) >= 0); 2 solved Lambda statement for finding sub-string in a string from list of strings [closed]
You need to do var result = lista.Where(foo => foo.idinvoice == 1 && listaIDprod.Contains(foo.idprod)).ToList(); Please look into your code, before putting on SO. class objeto() should be class objeto. Also, please choose sensible names for your classes and objects. 2 solved (C# Linq) Get items from a list when your ID is on another list … Read more
Now, what I want to do is select all DISTINCT by name elements from listA where the dictionary Attributes key equals any value from the Filters list. To define a distinct by property you could use define a group by name and take the first one. To define a filter, you could use Keys property … Read more
This is an XY problem. What you’re trying to achieve isn’t the same thing as what your question is asking. Your desired syntax wouldn’t work, even if you made this method async: var courses = await ids.ToChunks(1000) .Select(chunk => Courses.Where(c => chunk.Contains(c.CourseID))) .SelectMany(x => x).ToListAsync(); And the result you really want is just as easily … Read more
You can write it like this IEnumerable<int> range = Enumerable.Range(1, n); var sum = range.Aggregate(0, (x, y) => x + y); Sum of squares: IEnumerable<int> range = Enumerable.Range(1, n); var sum = range.Aggregate(0, (x, y) => x + y * y); 1 solved How to use self defined aggregate function with LINQ? (without using extension … Read more