C#获取类的属性和值的方法(含List转Datatable方法)

引言

为什么会引出这样的问题呢？其实，这是必然的，因为我们在日常的代码编写中，当使用到泛型，
如：public class ConvertHelper where T : class,new()
我们会发现此时想要对泛型T进行属性获取和值获取的时候，仿佛成了一个棘手的问题！

一、环境准备

1.1 创建测试类

 public class User
    {
    
    
        public string Id {
    
     get; set; }
        public string UserName {
    
     get; set; }
    }

1.2 创建List

public List<User> GetList()
    {
    
    
        List<User> list = new List<User>();
        string Id = Guid.NewGuid().ToString();
        User u1 = new U()
        {
    
    
            Id = Id,
            UserName = "UserName1"
        };
        list.Add(u1);
        User u2 = new U()
        {
    
    
            Id = Id,
            UserName = "UserName2"
        };
        list.Add(u2);
        User u3 = new U()
        {
    
    
            Id = Id,
            UserName = "UserName3"
        };
        list.Add(u3);
        User u4 = new U()
        {
    
    
            Id = Id,
            UserName = "UserName4"
        };
        list.Add(u4);
    }

二、获取泛型T的属性

2.1 代码实现

public class ConverHelper<T> where T:class,new()
    {
    
    
        public static void ToDatabale(List<T> tList)
        {
    
    
            T t = new T();
            var properties = t.GetType().GetProperties();
            foreach (var item in properties)
            {
    
    
                Console.WriteLine(item.Name);
            }
        }
    }

2.2 代码调用

 class Program
    {
    
    
        static void Main(string[] args)
        {
    
    
             ConverHelper<User>.ToDatabale(GetList())
        }
    }

三、获取泛型T的值

3.1 代码实现

public class ConverHelper<T> where T:class,new()
    {
    
    
        public static void ToDatabale(List<T> tList)
        {
    
    
            T t = new T();
            var properties = t.GetType().GetProperties();
            
            //获取属性的值
            for (int i = 0; i < tList.Count; i++)
            {
    
    
                for (int j = 0; j < properties.Length; j++)
                {
    
    
                    var property = properties[j].Name;
                    var value = tList[i].GetType().GetProperty(property).GetValue(tList[i]);
                    Console.WriteLine(property + "：" + value);
                }
            }
        }
    }

3.2 代码调用

 class Program
    {
    
    
        static void Main(string[] args)
        {
    
    
             ConverHelper<User>.ToDatabale(GetList())
        }
    }

四、扩展：List转DataTable

4.1 代码实现

public class ConverHelper<T> where T:class,new()
    {
    
    
        public static DataTable ToDatabale(List<T> tList)
        {
    
    
            DataTable dt = new DataTable();
            T t = new T();
            var properties = t.GetType().GetProperties();

            //添加列
            foreach (var item in properties)
            {
    
    
                dt.Columns.Add(item.Name, item.PropertyType);
            }
            
            //获取属性的值
            for (int i = 0; i < tList.Count; i++)
            {
    
    
                //添加行
                dt.Rows.Add();
                for (int j = 0; j < properties.Length; j++)
                {
    
    
                    var property = properties[j].Name;
                    var value = tList[i].GetType().GetProperty(property).GetValue(tList[i]);
                    //填充行列
                    dt.Rows[i][property] = value;
                }
            }
            return dt;
        }
    }

4.2 代码调用

 class Program
    {
    
    
        static void Main(string[] args)
        {
    
    
            DataTable dt = ConverHelper<User>.ToDatabale(list);
            for (int i = 0; i < dt.Rows.Count; i++)
            {
    
    
                Console.WriteLine("Id：" + dt.Rows[i]["Id"]);
                Console.WriteLine("UserName：" + dt.Rows[i]["UserName"]);
            }
        }
    }