[EF]分頁處理

之前實現數據真分頁，採用ADO.NET的方式，通常寫一存儲過程實現：

ALTER procedure [dbo].[UP_SqlDataPaging]
@tbName varchar(255),        --表名
@tbFields varchar(1000),      --返回字段
@OrderField varchar(255),   --排序的字段名
@PageSize int,                 --頁尺寸
@PageIndex int,                --頁碼
@OrderType bit,                --排序類型,1是升序,0是降序
@strWhere varchar(1500),    --查詢條件
@Total int output            --返回總記錄數
as
declare @strSql varchar(5000)     --主語句
declare @strOrder varchar(200)    --排序
declare @strSqlCount nvarchar(500)--查詢記錄總數主語句
declare @strtemp varchar(50)      --排序附加語句
--------------排序-----------------1是降序,0未升序
if @OrderType !=0
begin
set @strtemp= '>(select max('
set @strOrder='order by ' + @OrderField + ' asc '
end
else
begin
set @strtemp= '<(select min('
set @strOrder='order by '+ @OrderField + ' desc'
end
--------------總記錄數---------------
if @strWhere !=''
begin
set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName + 'where  '+ @strWhere
end
else
begin
set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName
end
--------------如果是第一頁------------
if @PageIndex =1
begin
if @strWhere !=''
begin
set @strSql = 'Select top' +str(@PageSize)+ ' ' + @tbFields + '  from '+ @tbName +' where ' + @strWhere + ' ' + @strOrder
end
else
begin
set @strSql = 'Select top' +str(@PageSize)+ ' ' + @tbFields + '  from '+ @tbName + ' ' + @strOrder
end
end
else
begin
if @strWhere !=''
begin
set @strSql='Select top ' +str(@PageSize) + ' ' + @tbFields
+' from ' + @tbName + ' where '+@OrderField +' '
+ @strtemp+ ' ' +@OrderField+ ') from (select top'
+str((@PageIndex-1)*@PageSize) + ' '+@OrderField +' from '+@tbName
+ @strWhere+ ' '+ @strOrder +') as tb)'+ @strOrder
end
else
begin
set @strSql='Select top ' + str(@PageSize) + ' ' + @tbFields
+' from ' + @tbName + ' where '+@OrderField + ' '
+ @strtemp+ ' ' +@OrderField+ ') from (select top'
+str((@PageIndex-1)*@PageSize) + ' '+@OrderField +' from '+@tbName
+ ' '+ @strOrder +') as tb)'+ @strOrder
end
end
exec sp_executesql @strSqlCount,N'@TotalCout int output',@Total output
exec(@strSql)

調用此存儲過程方式。實現過程過於繁瑣。
以下爲EF的一個控制檯程序測試：
利用Skip和Take方法快速實現分頁：

      public static void DoSkipTake() {

            using (var context = new KTStoreModel()) {


                var count = context.Products.Count();
                Console.Write("\n數據總行數：{0}\n", count);

                Console.Write("\n預設分頁數據項數：　5");
                int pcount = 5;
                int totalpages = count / 5 + 1;
                Console.Write("\n計算的總頁數：　{0}\n", totalpages);

                Console.Write("\n請輸入您要查詢的頁數：　");
                int pages = int.Parse(Console.ReadLine());

                Console.WriteLine("\n第 {0} 個分頁數據：　\n", pages);
                var products = (from product in context.Products
                                orderby product.Id
                                select product).                               
                                Skip((pages - 1) * pcount).
                                Take(pcount);

                foreach(var product in products)
                {
                    Console.WriteLine("　{0}\t{1}", product.Id, product.Name);
                }
                Console.Write("\n輸出所有數據項：　\n");
                var prds = from product in context.Products
                           orderby product.Id
                           select product;
                foreach (var product in prds)
                {
                    Console.WriteLine("　{0}\t{1}", product.Id, product.Name);
                }


                Console.ReadKey();
            }
        }