WebJan 17, 2010 · Use the GroupBy extension on IEnumerable () to group the numbers and extract the count of each. This creates the dictionary from the list and orders it in one statement. var ordered = list.GroupBy ( l => l ) .OrderByDescending ( g => g.Count () ) .ToDictionary ( g => g.Key, g.Count () ); Share Follow answered Jan 17, 2010 at 13:55 … Webvar results = persons.GroupBy ( p => p.PersonId, p => p.car, (key, g) => new { PersonId = key, Cars = g.ToList () }); Basically the contents of the group (when viewed as an IEnumerable) is a sequence of whatever values were in the projection ( p.car in this case) present for the given key.
c# - Group dictionary by multiple properties of key - Stack Overflow
WebJul 15, 2012 · The group part will give you an IGrouping>, and the subsequent ToDictionary will convert each group of key/value pairs back into a dictionary. EDIT: Note that this will always use the first letter. WebSep 18, 2024 · I need to find a way to group the value and loop through the group of dictionary values. For example, I need a loop like: int [] value_groups = new int [] { 10, 20, 30 }; foreach (int group1 in value_groups) { List group_keys = D0.Where (x => x.value == group1).ToList (); foreach (string key1 in group_keys) { how fast is 400cc
C# 从文本框中输入的字符串中读取所有字符,而不重复和计数每 …
WebApr 13, 2024 · var myDictionary = entities .GroupBy (e => e.EntityId) .Select (e => e.First ()) .ToDictionary (e => e.EntityId, async entity => await GetData (entity)); Unfortunately myDictionary is of type Dictionary> How to fill in the using async lambda in ToDictionary? c# linq dictionary async-await Share Follow asked Apr 13, 2024 at 14:05 WebMay 28, 2024 · LINQ Group By into a Dictionary Object; Using GroupBy / ToDictionary grouping by a List; C# Linq Group by with Dictionary-LINQ; Reading elements into a dictionary object using LINQ; C# - Convert a list to a dictionary. Let's begin by looking at an example of performing the group by: var objects = myCustomObjects.GroupBy(c => … WebFeb 18, 2024 · The following example shows how to group source elements by using something other than a property of the object for the group key. In this example, the key is the first letter of the student's last name. C#. var groupByFirstLetterQuery = from student in students group student by student.LastName [0]; foreach (var studentGroup in ... how fast is 420 knots