using System; using System.Collections.Generic; using System.Data; using System.Linq; using System.Reflection; using System.Text; using System.Threading.Tasks; namespace Com.AppCode.Extend { static public class TableConvert { #region DataTable 1 /// <summary> /// 将datatable转换为泛型集合 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="inputDataTable"></param> /// <returns></returns> public static List<TEntity> ToList<TEntity>(this DataTable inputDataTable) where TEntity : class, new() { if (inputDataTable == null) { throw new ArgumentNullException("input datatable is null"); } Type type = typeof(TEntity); PropertyInfo[] propertyInfos = type.GetProperties(); List<TEntity> lstEntitys = new List<TEntity>(); foreach (DataRow row in inputDataTable.Rows) { object obj = Activator.CreateInstance(type); foreach (PropertyInfo pro in propertyInfos) { foreach (DataColumn col in inputDataTable.Columns) { //如果直接查询的数据库，数据库是不区别大小写的，所以转换为小写忽略大小写的问题 if (col.ColumnName.ToLower().Equals(pro.Name.ToLower())) { //属性是否是可写的，如果是只读的属性跳过。 if (pro.CanWrite) { //判断类型，基本类型，如果是其他的类属性 if (pro.PropertyType == typeof(System.Int32)) { pro.SetValue(obj, Convert.ToInt32(row[pro.Name.ToLower()])); } else if (pro.PropertyType == typeof(System.String)) { pro.SetValue(obj, row[pro.Name.ToLower()].ToString()); } else if (pro.PropertyType == typeof(System.Boolean)) { pro.SetValue(obj, Convert.ToBoolean(row[pro.Name.ToLower()])); } else if (pro.PropertyType == typeof(System.DateTime)) { pro.SetValue(obj, Convert.ToDateTime(row[pro.Name.ToLower()])); } else if (pro.PropertyType == typeof(System.Int64)) { pro.SetValue(obj, Convert.ToInt64(row[pro.Name.ToLower()])); } else { pro.SetValue(obj, row[pro.Name.ToLower()]); } } } } } TEntity tEntity = obj as TEntity; lstEntitys.Add(tEntity); } return lstEntitys; } /// <summary> /// 将list转换为datatable /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="inputList"></param> /// <returns></returns> public static DataTable ToDataTable<TEntity>(this List<TEntity> inputList) where TEntity : class, new() { if (inputList == null) { throw new ArgumentNullException("inputList"); } DataTable dt = null; Type type = typeof(TEntity); if (inputList.Count == 0) { dt = new DataTable(type.Name); return dt; } else { dt = new DataTable(); } PropertyInfo[] propertyInfos = type.GetProperties(); foreach (var item in propertyInfos) { dt.Columns.Add(new DataColumn() { ColumnName = item.Name, DataType = item.PropertyType }); } foreach (var item in inputList) { DataRow row = dt.NewRow(); foreach (var pro in propertyInfos) { row[pro.Name] = pro.GetValue(item); } dt.Rows.Add(row); } return dt; } #endregion #region DataTable 2 /// <summary> /// DataTable转成List /// </summary> /// <typeparam name="T"></typeparam> /// <param name="dt"></param> /// <returns></returns> public static List<T> ToDataList<T>(this DataTable dt) { var list = new List<T>(); var plist = new List<PropertyInfo>(typeof(T).GetProperties()); foreach (DataRow item in dt.Rows) { T s = Activator.CreateInstance<T>(); for (int i = 0; i < dt.Columns.Count; i++) { PropertyInfo info = plist.Find(p => p.Name == dt.Columns[i].ColumnName); if (info != null) { try { if (!Convert.IsDBNull(item[i])) { object v = null; if (info.PropertyType.ToString().Contains("System.Nullable")) { v = Convert.ChangeType(item[i], Nullable.GetUnderlyingType(info.PropertyType)); } else { v = Convert.ChangeType(item[i], info.PropertyType); } info.SetValue(s, v, null); } } catch (Exception ex) { throw new Exception("字段[" + info.Name + "]转换出错," + ex.Message); } } } list.Add(s); } return list; } /// <summary> /// DataTable转成Dto /// </summary> /// <typeparam name="T"></typeparam> /// <param name="dt"></param> /// <returns></returns> public static T ToDataDto<T>(this DataTable dt) { T s = Activator.CreateInstance<T>(); if (dt == null || dt.Rows.Count == 0) { return s; } var plist = new List<PropertyInfo>(typeof(T).GetProperties()); for (int i = 0; i < dt.Columns.Count; i++) { PropertyInfo info = plist.Find(p => p.Name == dt.Columns[i].ColumnName); if (info != null) { try { if (!Convert.IsDBNull(dt.Rows[0][i])) { object v = null; if (info.PropertyType.ToString().Contains("System.Nullable")) { v = Convert.ChangeType(dt.Rows[0][i], Nullable.GetUnderlyingType(info.PropertyType)); } else { v = Convert.ChangeType(dt.Rows[0][i], info.PropertyType); } info.SetValue(s, v, null); } } catch (Exception ex) { throw new Exception("字段[" + info.Name + "]转换出错," + ex.Message); } } } return s; } /// <summary> /// 将实体集合转换为DataTable /// </summary> /// <typeparam name="T">实体类型</typeparam> /// <param name="entities">实体集合</param> public static DataTable ToTable<T>(List<T> entities) { var result = CreateTable<T>(); FillData(result, entities); return result; } /// <summary> /// 创建表 /// </summary> private static DataTable CreateTable<T>() { var result = new DataTable(); var type = typeof(T); foreach (var property in type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance)) { var propertyType = property.PropertyType; if ((propertyType.IsGenericType) && (propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))) propertyType = propertyType.GetGenericArguments()[0]; result.Columns.Add(property.Name, propertyType); } return result; } /// <summary> /// 填充数据 /// </summary> private static void FillData<T>(DataTable dt, IEnumerable<T> entities) { foreach (var entity in entities) { dt.Rows.Add(CreateRow(dt, entity)); } } /// <summary> /// 创建行 /// </summary> private static DataRow CreateRow<T>(DataTable dt, T entity) { DataRow row = dt.NewRow(); var type = typeof(T); foreach (var property in type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance)) { row[property.Name] = property.GetValue(entity) ?? DBNull.Value; } return row; } #endregion #region DataTable 3 /// <summary> /// DataTable转换为List /// </summary> /// <typeparam name="T">实体对象</typeparam> /// <param name="dt">datatable表</param> /// <returns>返回list集合</returns> static public List<T> TableToList<T>(DataTable dt) where T : new() { //定义集合 List<T> list = new List<T>(); //获得此模型的类型 Type type = typeof(T); //定义一个临时变量 string tempName = string.Empty; //遍历Datatable中所有的数据行 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(); //遍历该对象的所有属性 foreach (PropertyInfo pi in propertys) { //将属性名称赋值给临时变量 tempName = pi.Name; //检查DataTable是否包含此列（列名==对象的属性名） if (dt.Columns.Contains(tempName)) { //判断此属性是否有Setter if (!pi.CanWrite) continue;//该属性不可写，直接跳出 //取值 object value = dr[tempName]; //如果非空，则赋给对象的属性 if (value != DBNull.Value) { //加一重if判断，如果属性值是int32类型的，就进行一次强制转换 if (pi.GetMethod.ReturnParameter.ParameterType.Name == "Int32") { value = Convert.ToInt32(value); } pi.SetValue(t, value, null); } } } //对象添加到泛型集合中 list.Add(t); } return list; } #endregion } }