c#计算集合中各个属性的合计

一个通用的 C# 类 SumHelper，用于计算集合中各个属性的合计。这个方法CalculateSums<T>使用 LINQ 和表达式树来动态计算属性的总和.
cs 复制代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;

namespace YourNamespace
{
    /// <summary>
    /// 合计帮助类
    /// </summary>
    public static class SumHelper
    {
        /// <summary>
        /// 属性合计
        /// </summary>
        public static Dictionary<string, decimal> CalculateSums<T>(IEnumerable<T> list) where T : class
        {
            var type = typeof(T);
            var sum = new Dictionary<string, decimal>();
            var properties = type.GetProperties(BindingFlags.Public | BindingFlags.Instance);

            foreach (var property in properties)
            {
                // 检查属性类型
                if (property.PropertyType != typeof(int) && property.PropertyType != typeof(long) &&
                    property.PropertyType != typeof(decimal) && property.PropertyType != typeof(double) &&
                    property.PropertyType != typeof(int?) && property.PropertyType != typeof(long?) &&
                    property.PropertyType != typeof(decimal?) && property.PropertyType != typeof(double?))
                {
                    continue;
                }

                var parameter = Expression.Parameter(typeof(T), "x");
                var member = Expression.Property(parameter, property);

                // 处理可空类型
                var convertedMember = Expression.Convert(member, typeof(decimal));

                // 创建 lambda 表达式
                var lambda = Expression.Lambda<Func<T, decimal>>(convertedMember, parameter);
                
                // 计算总和
                var sumValue = list.AsQueryable().Sum(lambda);
                sum[property.Name + "Sum"] = sumValue;
            }

            return sum;
        }
    }
}
public class SampleData
{
    public int Value1 { get; set; }
    public decimal Value2 { get; set; }
    public double? Value3 { get; set; }
}

public class Program
{
    public static void Main()
    {
        var dataList = new List<SampleData>
        {
            new SampleData { Value1 = 10, Value2 = 20.5m, Value3 = 1.5 },
            new SampleData { Value1 = 5, Value2 = 10.5m, Value3 = null },
            new SampleData { Value1 = 15, Value2 = 30.0m, Value3 = 2.5 }
        };

        var sums = SumHelper.CalculateSums(dataList);

        foreach (var sum in sums)
        {
            Console.WriteLine($"{sum.Key}: {sum.Value}");
        }
    }
}