DataReader,DataTable利用泛型填充实体类

怼烎@ 2021-12-13 23:47 224阅读 0赞

using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 
 /// <summary>
 ///TestTableModel 的摘要说明
 /// </summary>
 public class TestTableModel
 {
 public int D_Id { get; set; }
 public string D_Name { get; set; }
 public string D_Password { get; set; }
 public string D_Else { get; set; }
 public decimal D_Amount { get; set; }
 }

using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Data;
 using System.Reflection;
 
 namespace MSCL
 {
 /// <summary>
 ///ObjectToList 的摘要说明
 /// </summary>
 public static class ObjectToList
 {
 /* --示例
 IDataReader dr = MSCL.SqlHelper.GetSqlDataReader("select * from TestTable where d_id in(6,7,8)");
 List<TestTableModel> t1 = MSCL.ObjectToList.DataReaderToList<TestTableModel>(dr);
 for (int i = 0; i < t1.Count; i++)
 {
 Response.Write(t1[i].D_Id + " ");
 Response.Write(t1[i].D_Name + " ");
 Response.Write(t1[i].D_Password + " ");
 Response.Write(t1[i].D_Else + " ");
 Response.Write(t1[i].D_Amount + " ");
 } 
 dr.Dispose();
 dr.Close();
 */
 
 /// <summary>
 /// DataReader利用泛型填充实体类
 /// </summary>
 /// <typeparam name="T">实体类</typeparam>
 /// <param name="reader">DataReader</param>
 /// <returns></returns>
 public static List<T> DataReaderToList<T>(IDataReader reader)
 {
 //实例化一个List<>泛型集合
 List<T> DataList = new List<T>();
 while (reader.Read())
 {
 T RowInstance = Activator.CreateInstance<T>();//动态创建数据实体对象
 //通过反射取得对象所有的Property
 foreach (PropertyInfo Property in typeof(T).GetProperties())
 {
 try
 {
 //取得当前数据库字段的顺序
 int Ordinal = reader.GetOrdinal(Property.Name);
 if (reader.GetValue(Ordinal) != DBNull.Value)
 {
 //将DataReader读取出来的数据填充到对象实体的属性里
 Property.SetValue(RowInstance, Convert.ChangeType(reader.GetValue(Ordinal), Property.PropertyType), null);
 }
 }
 catch
 {
 break;
 }
 }
 DataList.Add(RowInstance);
 }
 return DataList;
 }
 
 /// <summary>
 /// DataTable利用泛型填充实体类
 /// </summary>
 /// <typeparam name="T">实体类</typeparam>
 /// <param name="dt">DataTable</param>
 /// <returns></returns>
 public static List<T> DataTableToList<T>(DataTable dt) where T : new()
 {
 var list = new List<T>();
 if (dt == null) return list;
 var len = dt.Rows.Count;
 
 for (var i = 0; i < len; i++)
 {
 var info = new T();
 foreach (DataColumn dc in dt.Rows[i].Table.Columns)
 {
 var field = dc.ColumnName;
 var value = dt.Rows[i][field].ToString();
 if (string.IsNullOrEmpty(value)) continue;
 if (IsDate(value))
 {
 value = DateTime.Parse(value).ToString();
 }
 
 var p = info.GetType().GetProperty(field);
 
 try
 {
 if (p.PropertyType == typeof(string))
 {
 p.SetValue(info, value, null);
 }
 else if (p.PropertyType == typeof(int))
 {
 p.SetValue(info, int.Parse(value), null);
 }
 else if (p.PropertyType == typeof(bool))
 {
 p.SetValue(info, bool.Parse(value), null);
 }
 else if (p.PropertyType == typeof(DateTime))
 {
 p.SetValue(info, DateTime.Parse(value), null);
 }
 else if (p.PropertyType == typeof(float))
 {
 p.SetValue(info, float.Parse(value), null);
 }
 else if (p.PropertyType == typeof(double))
 {
 p.SetValue(info, double.Parse(value), null);
 }
 else
 {
 p.SetValue(info, value, null);
 }
 }
 catch (Exception)
 {
 //p.SetValue(info, ex.Message, null); 
 }
 }
 list.Add(info);
 }
 dt.Dispose(); dt = null;
 return list;
 }
 
 /// <summary>
 /// 是否是时间
 /// </summary>
 /// <param name="d"></param>
 /// <returns></returns>
 private static bool IsDate(string d)
 {
 DateTime d1;
 double d2;
 return !double.TryParse(d, out d2) && DateTime.TryParse(d, out d1);
 }
 }
 }

转载于:https://www.cnblogs.com/james1207/p/3303925.html