NET CORE List<T> 按字符串字段分组求和：详细教程和示例代码

{"title":"NET CORE List 按字符串字段分组求和：详细教程和示例代码","description":"本文介绍了如何在NET CORE中使用LINQ的GroupBy和Sum方法对List对象按给定的字符串字段进行分组并求和。通过示例代码演示了如何实现分组聚合功能，并解释了相关代码细节。","keywords":"NET CORE, List, GroupBy, Sum, 分组求和, LINQ, 字符串字段, 教程, 示例代码","content":"要按给定的字符串字段分组并求和，您可以使用LINQ的GroupBy和Sum方法来实现。以下是一个示例代码：\n\ncsharp\nusing System;\nusing System.Collections.Generic;\nusing System.Linq;\n\npublic class Program\n{\n public static void Main(string[] args)\n {\n List<Person> people = new List<Person>()\n {\n new Person() { Name = "John", Category = "A", Score = 10 },\n new Person() { Name = "Alice", Category = "A", Score = 20 },\n new Person() { Name = "Bob", Category = "B", Score = 30 },\n new Person() { Name = "Charlie", Category = "B", Score = 40 },\n new Person() { Name = "David", Category = "C", Score = 50 },\n };\n\n var sumByCategory = people.GroupBy(p => p.Category)\n .Select(g => new { Category = g.Key, TotalScore = g.Sum(p => p.Score) });\n\n foreach(var result in sumByCategory)\n {\n Console.WriteLine($"Category: {result.Category}, Total Score: {result.TotalScore}");\n }\n }\n}\n\npublic class Person\n{\n public string Name { get; set; }\n public string Category { get; set; }\n public int Score { get; set; }\n}\n\n\n在上面的示例中，我们首先定义了一个Person类，其中包含Name（姓名）、Category（类别）和Score（分数）属性。\n\n然后，我们创建了一个包含多个Person对象的List<Person>。我们使用GroupBy方法按Category字段进行分组，并使用Sum方法计算每个组的总分数。\n\n最后，我们使用foreach循环遍历每个分组的结果，并打印出类别和总分数。\n\n输出将是：\n\n\nCategory: A, Total Score: 30\nCategory: B, Total Score: 70\nCategory: C, Total Score: 50\n\n\n您可以根据自己的需求修改示例代码中的类和字段。"}