DataTable与实体类互相转换

  1     /// <summary>
  2     /// DataTable与实体类互相转换
  3     /// </summary>
  4     /// <typeparam name="T">实体类</typeparam>
  5     public class ModelHandler<T> where T : new()
  6     {
  7         #region DataTable转换成实体类
  8 
  9         /// <summary>
 10         /// 填充对象列表：用DataSet的第一个表填充实体类
 11         /// </summary>
 12         /// <param name="ds">DataSet</param>
 13         /// <returns></returns>
 14         public List<T> FillModel(DataSet ds)
 15         {
 16             if (ds == null || ds.Tables[0] == null || ds.Tables[0].Rows.Count == 0)
 17             {
 18                 return null;
 19             }
 20             else
 21             {
 22                 return FillModel(ds.Tables[0]);
 23             }
 24         }
 25 
 26         /// <summary>  
 27         /// 填充对象列表：用DataSet的第index个表填充实体类
 28         /// </summary>  
 29         public List<T> FillModel(DataSet ds, int index)
 30         {
 31             if (ds == null || ds.Tables.Count <= index || ds.Tables[index].Rows.Count == 0)
 32             {
 33                 return null;
 34             }
 35             else
 36             {
 37                 return FillModel(ds.Tables[index]);
 38             }
 39         }
 40 
 41         /// <summary>  
 42         /// 填充对象列表：用DataTable填充实体类
 43         /// </summary>  
 44         public List<T> FillModel(DataTable dt)
 45         {
 46             if (dt == null || dt.Rows.Count == 0)
 47             {
 48                 return null;
 49             }
 50             List<T> modelList = new List<T>();
 51             foreach (DataRow dr in dt.Rows)
 52             {
 53                 //T model = (T)Activator.CreateInstance(typeof(T));  
 54                 T model = new T();
 55                 for (int i = 0; i < dr.Table.Columns.Count; i++)
 56                 {
 57                     PropertyInfo propertyInfo = model.GetType().GetProperty(dr.Table.Columns[i].ColumnName);
 58                     if (propertyInfo != null && dr[i] != DBNull.Value)
 59                         propertyInfo.SetValue(model, dr[i], null);
 60                 }
 61                 
 62                 modelList.Add(model);
 63             }
 64             return modelList;
 65         }
 66 
 67         /// <summary>  
 68         /// 填充对象：用DataRow填充实体类
 69         /// </summary>  
 70         public T FillModel(DataRow dr)
 71         {
 72             if (dr == null)
 73             {
 74                 return default(T);
 75             }
 76 
 77             //T model = (T)Activator.CreateInstance(typeof(T));  
 78             T model = new T();
 79 
 80             for (int i = 0; i < dr.Table.Columns.Count; i++)
 81             {
 82                 PropertyInfo propertyInfo = model.GetType().GetProperty(dr.Table.Columns[i].ColumnName);
 83                 if (propertyInfo != null && dr[i] != DBNull.Value)
 84                     propertyInfo.SetValue(model,dr[i],null);
 85             }
 86             return model;
 87         }
 88 
 89         #endregion
 90 
 91         #region 实体类转换成DataTable
 92 
 93         /// <summary>
 94         /// 实体类转换成DataSet
 95         /// </summary>
 96         /// <param name="modelList">实体类列表</param>
 97         /// <returns></returns>
 98         public DataSet FillDataSet(List<T> modelList)
 99         {
100             if (modelList == null || modelList.Count == 0)
101             {
102                 return null;
103             }
104             else
105             {
106                 DataSet ds = new DataSet();
107                 ds.Tables.Add(FillDataTable(modelList));
108                 return ds;
109             }
110         }
111 
112         /// <summary>
113         /// 实体类转换成DataTable
114         /// </summary>
115         /// <param name="modelList">实体类列表</param>
116         /// <returns></returns>
117         public DataTable FillDataTable(List<T> modelList)
118         {
119             if (modelList == null || modelList.Count == 0)
120             {
121                 return null;
122             }
123             DataTable dt = CreateData(modelList[0]);
124 
125             foreach(T model in modelList)
126             {
127                 DataRow dataRow = dt.NewRow();
128                 foreach (PropertyInfo propertyInfo in typeof(T).GetProperties())
129                 {
130                     dataRow[propertyInfo.Name] = propertyInfo.GetValue(model, null);
131                 }
132                 dt.Rows.Add(dataRow);
133             }
134             return dt;
135         }
136 
137         /// <summary>
138         /// 根据实体类得到表结构
139         /// </summary>
140         /// <param name="model">实体类</param>
141         /// <returns></returns>
142         private DataTable CreateData(T model)
143         {
144             DataTable dataTable = new DataTable(typeof (T).Name);
145             foreach (PropertyInfo propertyInfo in typeof(T).GetProperties())
146             {
147                 dataTable.Columns.Add(new DataColumn(propertyInfo.Name, propertyInfo.PropertyType));
148             }
149             return dataTable;
150         }
151 
152         #endregion
153     }