一、泛型转DataSet
/// <summary> /// 泛型集合转换DataSet /// </summary> /// <typeparam name="T"></typeparam> /// <param name="list">泛型集合</param> /// <returns></returns> /// public static DataSet ToDataSet<T>(List<T> list) { return ToDataSet1<T>(list, null); } /// <summary> /// 泛型集合转换DataSet,并指定需要转换的字段 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="p_List">泛型集合</param> /// <param name="p_PropertyName">待转换属性名数组</param> /// <returns></returns> public static DataSet ToDataSet1<T>(List<T> p_List, params string[] p_PropertyName) { List<string> propertyNameList = new List<string>(); if (p_PropertyName != null) propertyNameList.AddRange(p_PropertyName); DataSet result = new DataSet(); DataTable _DataTable = new DataTable(); if (p_List.Count > 0) { Type type = typeof(T); PropertyInfo[] propertys = type.GetProperties(); foreach (PropertyInfo pi in propertys) { if (propertyNameList.Count == 0) { // 没有指定属性的情况下全部属性都要转换 _DataTable.Columns.Add(pi.Name, pi.PropertyType); } else { if (propertyNameList.Contains(pi.Name)) _DataTable.Columns.Add(pi.Name, pi.PropertyType); } } for (int i = 0; i < p_List.Count; i++) { ArrayList tempList = new ArrayList(); foreach (PropertyInfo pi in propertys) { if (propertyNameList.Count == 0) { object obj = pi.GetValue(p_List[i], null); tempList.Add(obj); } else { if (propertyNameList.Contains(pi.Name)) { object obj = pi.GetValue(p_List[i], null); tempList.Add(obj); } } } object[] array = tempList.ToArray(); _DataTable.LoadDataRow(array, true); } } result.Tables.Add(_DataTable); return result; } //调用 // List<实体类> List = new List<实体类>(); //DataSet ds = ToDataSet(List);
二、DataSet转泛型
第一种通过索引
/// <summary> /// DataSet装换为泛型集合 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="p_DataSet">DataSet</param> /// <param name="p_TableIndex">待转换数据表索引</param> /// <returns></returns> public static List<T> DataSetToList<T>(DataSet p_DataSet, int p_TableIndex) { if (p_DataSet == null || p_DataSet.Tables.Count < 0) return null; if (p_TableIndex > p_DataSet.Tables.Count - 1) return null; if (p_TableIndex < 0) p_TableIndex = 0; DataTable p_Data = p_DataSet.Tables[p_TableIndex]; // 返回值初始化 List<T> result = new List<T>(); for (int j = 0; j < p_Data.Rows.Count; j++) { T _t = (T)Activator.CreateInstance(typeof(T)); PropertyInfo[] propertys = _t.GetType().GetProperties(); foreach (PropertyInfo pi in propertys) { for (int i = 0; i < p_Data.Columns.Count; i++) { // 属性与字段名称一致的进行赋值 if (pi.Name.Equals(p_Data.Columns[i].ColumnName.ToUpper())) { // 数据库NULL值单独处理 if (p_Data.Rows[j][i] != DBNull.Value) { if (p_Data.Rows[j][i].GetType().Name == "Double") { pi.SetValue(_t, Convert.ToDecimal(p_Data.Rows[j][i]), null); } else { pi.SetValue(_t, p_Data.Rows[j][i], null); } } else pi.SetValue(_t, null, null); break; } } } result.Add(_t); } return result; } //调用 DataSet ds = new DataSet(); List<实体类> list = new List<实体类>(); dddss.Tables.Add(dt); //组合条件筛选完成之后转换为实体集合 list = DataSetToList<实体类>(ds, 索引);
第二种通过数据表名称
/// <summary> /// DataSet装换为泛型集合 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="p_DataSet">DataSet</param> /// <param name="p_TableName">待转换数据表名称</param> /// <returns></returns> /// 2008-08-01 22:47 HPDV2806 public static List<T> DataSetToList<T>(DataSet p_DataSet, string p_TableName) { int _TableIndex = 0; if (p_DataSet == null || p_DataSet.Tables.Count < 0) return null; if (string.IsNullOrEmpty(p_TableName)) return null; for (int i = 0; i < p_DataSet.Tables.Count; i++) { // 获取Table名称在Tables集合中的索引值 if (p_DataSet.Tables[i].TableName.Equals(p_TableName)) { _TableIndex = i; break; } } return DataSetToList<T>(p_DataSet, _TableIndex); } /// <summary> /// DataSet装换为泛型集合 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="p_DataSet">DataSet</param> /// <param name="p_TableIndex">待转换数据表索引</param> /// <returns></returns> /// 2008-08-01 22:46 HPDV2806 public static List<T> DataSetToList<T>(DataSet p_DataSet, int p_TableIndex) { if (p_DataSet == null || p_DataSet.Tables.Count < 0) return null; if (p_TableIndex > p_DataSet.Tables.Count - 1) return null; if (p_TableIndex < 0) p_TableIndex = 0; DataTable p_Data = p_DataSet.Tables[p_TableIndex]; // 返回值初始化 List<T> result = new List<T>(); for (int j = 0; j < p_Data.Rows.Count; j++) { T _t = (T)Activator.CreateInstance(typeof(T)); PropertyInfo[] propertys = _t.GetType().GetProperties(); foreach (PropertyInfo pi in propertys) { for (int i = 0; i < p_Data.Columns.Count; i++) { // 属性与字段名称一致的进行赋值 if (pi.Name.Equals(p_Data.Columns[i].ColumnName.ToUpper())) { // 数据库NULL值单独处理 if (p_Data.Rows[j][i] != DBNull.Value) { if (p_Data.Rows[j][i].GetType().Name == "Double") { pi.SetValue(_t, Convert.ToDecimal(p_Data.Rows[j][i]), null); } else { pi.SetValue(_t, p_Data.Rows[j][i], null); } } else pi.SetValue(_t, null, null); break; } } } result.Add(_t); } return result; } //调用 DataSet ds = new DataSet(); List<实体类> list = new List<实体类>(); dddss.Tables.Add(dt); //组合条件筛选完成之后转换为实体集合 list = DataSetToList<实体类>(ds, 表名);