/// 
    /// DataTable与实体类互相转换    /// 
    /// 
     
      实体类
         public class ModelHandler
     
       where T : new()    {        #region DataTable转换成实体类        /// 
      
        /// 填充对象列表：用DataSet的第一个表填充实体类        /// 
        /// 
      DataSet        /// 
              public List
      
        FillModel(DataSet ds)        {            if (ds == null || ds.Tables[0] == null || ds.Tables[0].Rows.Count == 0)            {                return null;            }            else            {                return FillModel(ds.Tables[0]);            }        }        /// 
       
          /// 填充对象列表：用DataSet的第index个表填充实体类        /// 
          public List
       
         FillModel(DataSet ds, int index)        {            if (ds == null || ds.Tables.Count <= index || ds.Tables[index].Rows.Count == 0)            {                return null;            }            else            {                return FillModel(ds.Tables[index]);            }        }        /// 
        
          /// 填充对象列表：用DataTable填充实体类        /// 
          public List
        
          FillModel(DataTable dt)        {            if (dt == null || dt.Rows.Count == 0)            {                return null;            }            List
         
           modelList = new List
          
           (); foreach (DataRow dr in dt.Rows) { //T model = (T)Activator.CreateInstance(typeof(T)); T model = new T(); for (int i = 0; i < dr.Table.Columns.Count; i++) { PropertyInfo propertyInfo = model.GetType().GetProperty(dr.Table.Columns[i].ColumnName); if (propertyInfo != null && dr[i] != DBNull.Value) propertyInfo.SetValue(model, dr[i], null); } modelList.Add(model); } return modelList; } /// 
           
 /// 填充对象：用DataRow填充实体类 /// 
 public T FillModel(DataRow dr) { if (dr == null) { return default(T); } //T model = (T)Activator.CreateInstance(typeof(T)); T model = new T(); for (int i = 0; i < dr.Table.Columns.Count; i++) { PropertyInfo propertyInfo = model.GetType().GetProperty(dr.Table.Columns[i].ColumnName); if (propertyInfo != null && dr[i] != DBNull.Value) propertyInfo.SetValue(model, dr[i], null); } return model; } #endregion #region 实体类转换成DataTable /// 
           
 /// 实体类转换成DataSet /// 
 /// 
           实体类列表 /// 
            public DataSet FillDataSet(List
           
             modelList) { if (modelList == null || modelList.Count == 0) { return null; } else { DataSet ds = new DataSet(); ds.Tables.Add(FillDataTable(modelList)); return ds; } } /// 
            
 /// 实体类转换成DataTable /// 
 /// 
            实体类列表 /// 
             public DataTable FillDataTable(List
            
              modelList) { if (modelList == null || modelList.Count == 0) { return null; } DataTable dt = CreateData(modelList[0]); foreach (T model in modelList) { DataRow dataRow = dt.NewRow(); foreach (PropertyInfo propertyInfo in typeof(T).GetProperties()) { object drValue = propertyInfo.GetValue(model, null); dataRow[propertyInfo.Name] = drValue == null ? DBNull.Value : drValue; } dt.Rows.Add(dataRow); } return dt; } /// 
             
 /// 根据实体类得到表结构 /// 
 /// 
             实体类 /// 
              private DataTable CreateData(T model) { DataTable dataTable = new DataTable(typeof(T).Name); foreach (PropertyInfo propertyInfo in typeof(T).GetProperties()) { dataTable.Columns.Add(new DataColumn(propertyInfo.Name, Nullable.GetUnderlyingType(propertyInfo.PropertyType) ?? propertyInfo.PropertyType)); } return dataTable; } #endregion }