linq查询DataView

转至：  http://blog.csdn.net/livening/article/details/6043081

  

  namespace UseDataView  
    {  
        class Program  
        {  
            static void Main(string[] args)  
            {  
                CreateDataVeiw( );  
                UseDataView( );  
            }  
      
            static DataSet BuildDataSet( )  
            {  
                //创建Students数据集  
                DataSet ds = new DataSet("Students");  
                //创建Students数据表，并添加到数据集  
                //Students数据表包含学生信息  
                DataTable dtStu = new DataTable("Students");  
                ds.Tables.Add(dtStu);  
                //添加学生信息记录的列信息  
                dtStu.Columns.AddRange(new DataColumn[]{  
                    new DataColumn("Name", Type.GetType("System.String")),  
                    new DataColumn("XingBie", Type.GetType("System.String")),  
                    new DataColumn("Age", Type.GetType("System.Int32")),  
                });  
                //添加学生信息的行信息  
                dtStu.Rows.Add("张三", "男", 20);  
                dtStu.Rows.Add("李四", "男", 19);  
                dtStu.Rows.Add("王霞", "女", 21);  
                dtStu.Rows.Add("赵敏", "女", 22);  
                dtStu.Rows.Add("吴安", "男", 18);  
                dtStu.Rows.Add("杨花", "女", 23);  
                //返回数据集  
                return ds;  
            }  
      
            static void CreateDataVeiw( )  
            {  
                //获取数据源  
                DataSet ds = BuildDataSet( );  
                DataTable dt = ds.Tables["Students"];  
                //用DataTable创建DataView  
                DataView dvDt = dt.AsDataView( );  
                //用LINQ查询创建DataView  
                EnumerableRowCollection<DataRow> query1 =  
                    from stu in dt.AsEnumerable( )  
                    select stu;  
                DataView dvNml = query1.AsDataView( );  
                //用LINQ查询创建具有过滤信息的DataView  
                EnumerableRowCollection<DataRow> query2 =  
                    from stu in dt.AsEnumerable( )  
                    where stu.Field<string>("Name").StartsWith("杨")  
                    select stu;  
                DataView dvFilter = query2.AsDataView( );  
                //用LINQ查询创建具有排序信息的DataView  
                EnumerableRowCollection<DataRow> query3 =  
                    from stu in dt.AsEnumerable( )  
                    orderby stu.Field<int>("Age")  
                    select stu;  
                DataView dvSort = query3.AsDataView( );  
            }  
      
            static void UseDataView( )  
            {  
                //获取数据源  
                DataSet ds = BuildDataSet( );  
                DataTable dt = ds.Tables["Students"];  
                //用DataTable创建DataView  
                DataView dvDt = dt.AsDataView( );  
                //通过RowFilter属性设置DataView过滤信息,只需要年龄大于20岁的学生记录  
                dvDt.RowFilter = "Age > 20";  
                //设置RowFilter为null或空字符串，清除过滤信息，二选一  
                dvDt.RowFilter = string.Empty;  
                dvDt.RowFilter = null;  
                //通过Sort属性设置DataView过滤信息  
                dvDt.Sort = "Age asc, Name desc";  
                //设置RowFilter为null或空字符串，清除过滤信息，二选一  
                dvDt.Sort = string.Empty;  
                dvDt.Sort = null;  
            }  
        }  
    }