获取通用列表项的计数

Question

I have a generic list of int List<int>() and I want to know Count of a item of it. How can I do it?

Answer 1

使用扩展方法是最简单的方法

int count = list.Count(i => i > 10);// get the count of those which is bigger than 10

Answer 2

如果要计算列表中项目数的计数，可以使用表达式执行此操作：

int count = myList.Count(i => i.Equals(5));

Answer 3

Count of A Generic List (generated from stored procedure)

List<GetDivisionsForGroup> GroupDivision = new List<GetDivisionsForGroup>();
        String storedProcedures = "Sp_GetDivisionsForGroup " + grpid;
        GroupDivision = db.ExecuteStoreQuery<GetDivisionsForGroup>("exec " + storedProcedures).ToList();

        if (GroupDivision.Count > 0)
        {

        }

Answer 4

http://code.msdn.microsoft.com/LINQ-Aggregate-Operators-c51b3869

public void Linq73() 
{ 
    int[] factorsOf300 = { 2, 2, 3, 5, 5 }; 

    int uniqueFactors = factorsOf300.Distinct().Count(); 

    Console.WriteLine("There are {0} unique factors of 300.", uniqueFactors); 
}