DataSet与泛型集合间的互相转换

/// <summary> 
    /// 泛型集合与DataSet互相转换 
    /// </summary> 
    public class IListDataSet 
    { 

        /// <summary> 
        /// 集合装换DataSet 
        /// </summary> 
        /// <param name="list">集合</param> 
        /// <returns></returns> 
        /// 2008-08-01 22:08 HPDV2806 
        public static DataSet ToDataSet( IList p_List ) 
        { 
            DataSet result = new DataSet(); 
            DataTable _DataTable = new DataTable(); 
            if ( p_List.Count > 0 ) 
            { 
                PropertyInfo[] propertys = p_List[0].GetType().GetProperties(); 
                foreach ( PropertyInfo pi in propertys ) 
                { 
                    _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 ) 
                    { 
                        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; 
        } 

        /// <summary> 
        /// 泛型集合转换DataSet 
        /// </summary> 
        /// <typeparam name="T"></typeparam> 
        /// <param name="list">泛型集合</param> 
        /// <returns></returns> 
        /// 2008-08-01 22:43 HPDV2806 
        public static DataSet ToDataSet<T>( IList<T> list ) 
        { 
            return ToDataSet<T>( list, null ); 
        } 


        /// <summary> 
        /// 泛型集合转换DataSet 
        /// </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> 
        /// 2008-08-01 22:44 HPDV2806 
        public static DataSet ToDataSet<T>( IList<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 ) 
            { 
                PropertyInfo[] propertys = p_List[0].GetType().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; 
        } 

        /// <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 IList<T> DataSetToIList<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 
            IList<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 ) ) 
                        { 
                            // 数据库NULL值单独处理 
                            if ( p_Data.Rows[j][i] != DBNull.Value ) 
                                pi.SetValue( _t, p_Data.Rows[j][i], null ); 
                            else 
                                pi.SetValue( _t, null, null ); 
                            break; 
                        } 
                    } 
                } 
                result.Add( _t ); 
            } 
            return result; 
        } 

        /// <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 IList<T> DataSetToIList<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 DataSetToIList<T>( p_DataSet, _TableIndex ); 
        } 
}

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/veryhappy/archive/2008/08/04/2764333.aspx

 利用反射机制将DataTable的字段与自定义类型的公开属性互相赋值。注意：从DataSet到IList<T>的转换，自定义类型的公开属性必须与DataTable中的字段名称一致，才能到达想要的结果。建议DataTable的定义从数据库来，自定义类型用O/R Mapping的方式获得。