C# Linq语句select 进行类型转换,where语句条件筛选

最新推荐文章于 2024-11-28 07:00:00 发布

原创最新推荐文章于 2024-11-28 07:00:00 发布 · 617 阅读

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#linq #c# #开发语言 #c语言

该代码示例展示了如何使用C#中的Linq方法将`Student`对象列表转换为`GoodStudent`对象列表，并应用条件筛选，只保留测试通过的学生信息。最后，筛选后的结果打印出来。

        public class Student
        {
            public string FirstName { get; set; }
            public string LastName { get; set; }
            public DateTime? Birthday { get; set; }
            public bool TestPassed { get; set; }

            public Student(string firstName, string lastName, DateTime? birthday, bool testPassed)
            {
                this.FirstName = firstName;
                this.LastName = lastName;
                this.Birthday = birthday;
                this.TestPassed = testPassed;
            }
         }

        public class GoodStudent
        {
                public string FirstName { get; set; }
                public string LastName { get; set; }
                public bool TestPassed { get; set; }

        }

              var students = new List<Student>();
              students.Add(new Student("Kana", "Yamada", null, true));
              students.Add(new Student("Keita", "Maeda", Convert.ToDateTime("2010/05/15"), true));
              students.Add(new Student("Kaede", "Tanaka", Convert.ToDateTime("2009/02/01"), false));
              students.Add(new Student("Ryota", "Suzuki", Convert.ToDateTime("2010/11/24"), true));
              students.Add(new Student("Saki", "Taguchi", null, false));
              students.Add(new Student("seki", "gi", null, true));
             
             //通过Linq语句select 进行类型转换，where语句进行条件筛选 
             var list4 = students.Select(x=>new GoodStudent  //表示list4的结果是一个GoodStudent类
                { 
                    FirstName=x.FirstName,
                    LastName=x.LastName,
                    TestPassed=x.TestPassed
                }).Where(a => a.TestPassed == true).ToList();
             foreach (var item in list4)
             {
                 Console.WriteLine();
                 Console.WriteLine(item.FirstName + "******list4****" + item.LastName);
             }
             //处理结果是：
            Kana******list4****Yamada
			Keita******list4****Maeda
			Ryota******list4****Suzuki
			seki******list4****gi