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DataSetHelper dsHelper = DataSetHelper(); List<M_Order> listSrc = new List<M_Order>(); listSrc = (List<M_Order>)ModelConvertHelper<M_Order>.ConvertToModel(ds.Tables[0]); var sums = listSrc.GroupBy(x => new { x.Name }) .Select(group => new { Keys= group.Key, OrderCount = group.Sum(x => x.OrderCount) }); #region 类 private class M_Order { public int OrderCount { get; set; } public string Name { get; set; } public string Date { get; set; } } #endregion

namespace common { public class ModelConvertHelper<T> where T : new() { public static IList<T> ConvertToModel(DataTable dt) { // 定义集合 IList<T> ts = new List<T>(); // 获得此模型的类型 Type type = typeof(T); string tempName = ""; foreach (DataRow dr in dt.Rows) { T t = new T(); // 获得此模型的公共属性 PropertyInfo[] propertys = t.GetType().GetProperties(); foreach (PropertyInfo pi in propertys) { tempName = pi.Name; // 检查DataTable是否包含此列 if (dt.Columns.Contains(tempName)) { // 判断此属性是否有Setter if (!pi.CanWrite) continue; object value = dr[tempName]; if (value != DBNull.Value) pi.SetValue(t, value, null); } } ts.Add(t); } return ts; } } }

http://stackoverflow.com/questions/363655/c-list-groupby-2-values