C# List实现行转列的通用方案

/// <summary> /// 家庭费用情况 /// </summary> public class House { /// <summary> /// 户主姓名 /// </summary> public string Name { get; set; } /// <summary> /// 所属行政区域 /// </summary> public string Area { get; set; } /// <summary> /// 月份 /// </summary> public string Month { get; set; } /// <summary> /// 电费金额 /// </summary> public double DfMoney { get; set; } /// <summary> /// 水费金额 /// </summary> public double SfMoney { get; set; } /// <summary> /// 燃气金额 /// </summary> public double RqfMoney { get; set; } }

/// <summary> /// 动态Linq方式实现行转列 /// </summary> /// <param name="list">数据</param> /// <param name="DimensionList">维度列</param> /// <param name="DynamicColumn">动态列</param> /// <returns>行转列后数据</returns> private static List<dynamic> DynamicLinq<T>(List<T> list, List<string> DimensionList, string DynamicColumn, out List<string> AllDynamicColumn) where T : class { //获取所有动态列 var columnGroup = list.GroupBy(DynamicColumn, "new(it as Vm)") as IEnumerable<IGrouping<dynamic, dynamic>>; List<string> AllColumnList = new List<string>(); foreach (var item in columnGroup) { if (!string.IsNullOrEmpty(item.Key)) {  AllColumnList.Add(item.Key); } } AllDynamicColumn = AllColumnList; var dictFunc = new Dictionary<string, Func<T, bool>>(); foreach (var column in AllColumnList) { var func = DynamicExpression.ParseLambda<T, bool>(string.Format("{0}==/"{1}/"", DynamicColumn, column)).Compile(); dictFunc[column] = func; } //获取实体所有属性 Dictionary<string, PropertyInfo> PropertyInfoDict = new Dictionary<string, PropertyInfo>(); Type type = typeof(T); var propertyInfos = type.GetProperties(BindingFlags.Instance | BindingFlags.Public); //数值列 List<string> AllNumberField = new List<string>(); foreach (var item in propertyInfos) { PropertyInfoDict[item.Name] = item; if (item.PropertyType == typeof(int) || item.PropertyType == typeof(double) || item.PropertyType == typeof(float)) {  AllNumberField.Add(item.Name); } } //分组 var dataGroup = list.GroupBy(string.Format("new ({0})", string.Join(",", DimensionList)), "new(it as Vm)") as IEnumerable<IGrouping<dynamic, dynamic>>; List<dynamic> listResult = new List<dynamic>(); IDictionary<string, object> itemObj = null; T vm2 = default(T); foreach (var group in dataGroup) { itemObj = new ExpandoObject(); var listVm = group.Select(e => e.Vm as T).ToList(); //维度列赋值 vm2 = listVm.FirstOrDefault(); foreach (var key in DimensionList) {  itemObj[key] = PropertyInfoDict[key].GetValue(vm2); } foreach (var column in AllColumnList) {  vm2 = listVm.FirstOrDefault(dictFunc[column]);  if (vm2 != null)  {  foreach (string name in AllNumberField)  {  itemObj[name + column] = PropertyInfoDict[name].GetValue(vm2);  }  } } listResult.Add(itemObj); } return listResult; }

/// <summary> /// EF实体查询封装  /// </summary> /// <typeparam name="T">实体类型</typeparam> /// <param name="Query">IQueryable对象</param> /// <param name="gridParam">过滤条件</param> /// <returns>查询结果</returns> public static EFPaginationResult<T> PageQuery<T>(this IQueryable<T> Query, QueryCondition gridParam) { //查询条件 EFFilter filter = GetParameterSQL<T>(gridParam); var query = Query.Where(filter.Filter, filter.ListArgs.ToArray()); //查询结果 EFPaginationResult<T> result = new EFPaginationResult<T>(); if (gridParam.IsPagination) { int PageSize = gridParam.PageSize; int PageIndex = gridParam.PageIndex < 0 ? 0 : gridParam.PageIndex; //获取排序信息 string sort = GetSort(gridParam, typeof(T).FullName); result.Data = query.OrderBy(sort).Skip(PageIndex * PageSize).Take(PageSize).ToList<T>(); if (gridParam.IsCalcTotal) {  result.Total = query.Count();  result.TotalPage = Convert.ToInt32(Math.Ceiling(result.Total * 1.0 / PageSize)); } else {  result.Total = result.Data.Count(); } } else { result.Data = query.ToList(); result.Total = result.Data.Count(); } return result; }

/// <summary> /// 通过查询条件,获取参数化查询SQL /// </summary> /// <param name="gridParam">过滤条件</param> /// <returns>过滤条件字符</returns> private static EFFilter GetParameterSQL<T>(QueryCondition gridParam) { EFFilter result = new EFFilter(); //参数值集合 List<object> listArgs = new List<object>(); string filter = "1=1"; #region "处理动态过滤条件" if (gridParam.FilterList != null && gridParam.FilterList.Count > 0) { StringBuilder sb = new StringBuilder(); int paramCount = 0; DateTime dateTime; //操作符 string strOperator = string.Empty; foreach (var item in gridParam.FilterList) {  //字段名称为空则跳过  if (string.IsNullOrEmpty(item.FieldName))  {  continue;  }  //匹配枚举，防止SQL注入  Operator operatorEnum = (Operator)Enum.Parse(typeof(Operator), item.Operator, true);  //跳过字段值为空的  if (operatorEnum != Operator.Null && operatorEnum != Operator.NotNull && string.IsNullOrEmpty(item.FieldValue))  {  continue;  }  strOperator = operatorEnum.GetDescription();  if (item.IgnoreCase && !item.IsDateTime)  {  //2016-07-19添加查询时忽略大小写比较  item.FieldValue = item.FieldValue.ToLower();  item.FieldName = string.Format("{0}.ToLower()", item.FieldName);  }  switch (operatorEnum)  {  //等于,不等于，小于，大于，小于等于，大于等于  case Operator.EQ:  case Operator.NE:  case Operator.GT:  case Operator.GE:  case Operator.LT:  case Operator.LE:  if (item.IsDateTime)  {  if (DateTime.TryParse(item.FieldValue, out dateTime))  {   if (!item.FieldValue.Contains("00:00:00") && dateTime.ToString("HH:mm:ss") == "00:00:00")   {   if (operatorEnum == Operator.LE)   {   listArgs.Add(DateTime.Parse(dateTime.ToString("yyyy-MM-dd") + " 23:59:59"));   }   else   {   listArgs.Add(dateTime);   }   }   else   {   listArgs.Add(dateTime);   }   sb.AppendFormat(" AND {0} {1} @{2}", item.FieldName, strOperator, paramCount);  }  }  else  {  listArgs.Add(ConvertToType(item.FieldValue, GetPropType<T>(item.FieldName)));  sb.AppendFormat(" AND {0} {1} @{2}", item.FieldName, strOperator, paramCount);  }  paramCount++;  break;  case Operator.Like:  case Operator.NotLike:  case Operator.LLike:  case Operator.RLike:  listArgs.Add(item.FieldValue);  if (operatorEnum == Operator.Like)  {  sb.AppendFormat(" AND {0}.Contains(@{1})", item.FieldName, paramCount);  }  else if (operatorEnum == Operator.NotLike)  {  sb.AppendFormat(" AND !{0}.Contains(@{1})", item.FieldName, paramCount);  }  else if (operatorEnum == Operator.LLike)  {  sb.AppendFormat(" AND {0}.EndsWith(@{1})", item.FieldName, paramCount);  }  else if (operatorEnum == Operator.RLike)  {  sb.AppendFormat(" AND {0}.StartsWith(@{1})", item.FieldName, paramCount);  }  paramCount++;  break;  case Operator.Null:  listArgs.Add(item.FieldValue);  sb.AppendFormat(" AND {0}=null", item.FieldName);  paramCount++;  break;  case Operator.NotNull:  listArgs.Add(item.FieldValue);  sb.AppendFormat(" AND {0}!=null", item.FieldName);  paramCount++;  break;  case Operator.In:  sb.AppendFormat(" AND (");  foreach (var schar in item.FieldValue.Split(','))  {  listArgs.Add(schar);  sb.AppendFormat("{0}=@{1} or ", item.FieldName, paramCount);  paramCount++;  }  sb.Remove(sb.Length - 3, 3);  sb.AppendFormat(" )");  break;  case Operator.NotIn:  sb.AppendFormat(" AND (");  foreach (var schar in item.FieldValue.Split(','))  {  listArgs.Add(schar);  sb.AppendFormat("{0}!=@{1} and ", item.FieldName, paramCount);  paramCount++;  }  sb.Remove(sb.Length - 3, 3);  sb.AppendFormat(" )");  break;  }  if (sb.ToString().Length > 0)  {  filter = sb.ToString().Substring(4, sb.Length - 4);  } } #endregion } result.Filter = filter; result.ListArgs = listArgs; return result; }