C#中字典Dictionary与自定义类型CustomType之间的转换

news2024/11/24 16:07:21

思路：

可以使用反射System.Reflection来获取类的具体属性，

属性名称就映射字典的键Key。

新建控制台程序DictionaryCustomClassConversionDemo

第一步、新建关键转换类ConversionUtil。

类ConversionUtil的源代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace DictionaryCustomClassConversionDemo
{
    /// <summary>
    /// 字典Dictionary与自定义类CustomClass属性之间的转化
    /// 斯内科 2024-05-10
    /// </summary>
    public class ConversionUtil
    {
        /// <summary>
        /// 将一个实体类的属性转化为键值对集合，键为属性名PropertyName，值为对应的值
        /// </summary>
        /// <typeparam name="T">一种自定义类，该类必须已实例化</typeparam>
        /// <param name="obj">实例化后的类对象</param>
        /// <returns>返回转化后的字典</returns>
        public static Dictionary<string, object> CustomClassToDictionary<T>(T obj) where T : class, new()
        {
            Dictionary<string, object> dict = new Dictionary<string, object>();
            Type type = typeof(T);
            PropertyInfo[] propertyInfos = type.GetProperties();
            for (int i = 0; i < propertyInfos.Length; i++)
            {
                string key = propertyInfos[i].Name;
                object val = propertyInfos[i].GetValue(obj);
                dict.Add(key, val);
            }
            return dict;
        }

        /// <summary>
        /// 将字典转化为实例化类，如果类的属性名称在字典中存在该键key，就使用该键对应的值为类的属性key赋值【注意，转化可能因值的类型、范围等不同而导致失败】
        /// 如果类的属性名称在字典中不存在该键key，则不进行赋值，只是按属性对应类型的默认值处理
        /// </summary>
        /// <typeparam name="T">要转化的目标类型</typeparam>
        /// <param name="dict">键值对字典</param>
        /// <returns>要获取的目标实例化类对象，如果字典为空，则按类的默认值处理</returns>
        public static T DictionaryToCustomClass<T>(Dictionary<string, object> dict) where T : class
        {
            T obj = default(T);
            if (dict == null || dict.Count == 0) 
            {
                return obj;
            }
            Type type = typeof(T);
            obj = (T)Activator.CreateInstance(type);
            PropertyInfo[] propertyInfos = type.GetProperties();
            for (int i = 0; i < propertyInfos.Length; i++)
            {
                string key = propertyInfos[i].Name;
                if (dict.ContainsKey(key)) 
                {
                    propertyInfos[i].SetValue(obj, dict[key]);
                }
            }
            return obj;
        }
    }
}

二、新建实体测试类TestClass。

测试类TestClass源程序如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DictionaryCustomClassConversionDemo
{
    /// <summary>
    /// 测试类
    /// </summary>
    public class TestClass
    {
        /// <summary>
        /// 主键
        /// </summary>
        public int CoreID { get; set; }

        /// <summary>
        /// 档位编号
        /// </summary>
        public int LevelId { get; set; }

        /// <summary>
        /// 电压下限
        /// </summary>
        public double VoltageMin { get; set; }

        /// <summary>
        /// 电压上限
        /// </summary>
        public double VoltageMax { get; set; }

        /// <summary>
        /// 内阻值
        /// </summary>
        public string Resistance { get; set; }

        /// <summary>
        /// 修改时间
        /// </summary>
        public DateTime ModifyTime { get; set; }

        public override string ToString()
        {
            return $"{{CoreID:{CoreID},\nLevelId:{LevelId},\nVoltageMin:{VoltageMin},\nVoltageMax:{VoltageMax},\nResistance:{Resistance},\nModifyTime:{ModifyTime.ToString("yyyy-MM-dd HH:mm:ss")}}}";
        }
    }
}

三、调用测试Program如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DictionaryCustomClassConversionDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.SetWindowSize(100, 60);
            try
            {
                TestClass testClass = new TestClass()
                {
                    CoreID = 6,
                    LevelId = 3,
                    VoltageMin = 3.10,
                    VoltageMax = 3.99,
                    Resistance = "888MΩ",
                    ModifyTime = DateTime.Now
                };
                Console.WriteLine($"--------打印原对象信息:--------");
                Console.WriteLine(testClass);
                Dictionary<string, object> dict = ConversionUtil.CustomClassToDictionary(testClass);
                Console.WriteLine("--------打印类对象转化后的字典信息:--------");
                for (int i = 0; i < dict.Count; i++)
                {
                    KeyValuePair<string, object> keyValuePair = dict.ElementAt(i);
                    Console.WriteLine($"{keyValuePair.Key}:{keyValuePair.Value}");
                }
                Console.WriteLine();
                Console.WriteLine("--------测试字典转化为类--------");

                dict["Resistance"] = "333MΩ";
                dict["LevelId"] = 1;
                dict["VoltageMax"] = 5;
                dict.Add("额外参数", "额外值");
                Console.WriteLine("--------打印原字典信息1:--------");
                for (int i = 0; i < dict.Count; i++)
                {
                    KeyValuePair<string, object> keyValuePair = dict.ElementAt(i);
                    Console.WriteLine($"{keyValuePair.Key}:{keyValuePair.Value}");
                }
                TestClass testObj1 = ConversionUtil.DictionaryToCustomClass<TestClass>(dict);
                Console.WriteLine("--------打印字典转化为类对象1--------");
                Console.WriteLine(testObj1);
                Console.WriteLine();
                dict["Resistance"] = 66666;
                dict["LevelId"] = 5;
                Console.WriteLine("--------打印原字典信息2:--------");
                for (int i = 0; i < dict.Count; i++)
                {
                    KeyValuePair<string, object> keyValuePair = dict.ElementAt(i);
                    Console.WriteLine($"{keyValuePair.Key}:{keyValuePair.Value}");
                }
                TestClass testObj2 = ConversionUtil.DictionaryToCustomClass<TestClass>(dict);
                Console.WriteLine("--------打印字典转化为类对象2--------");
                Console.WriteLine(testObj2);
            }
            catch (Exception ex) 
            {
                Console.WriteLine($"{ex.Message}.异常类型【{ex.GetType()}】");
            }
            Console.ReadLine();
        }
    }
}