网格视图绑定到SqlDataSource创建分页麻烦

Question

I am developing a web app using C#, .net 4. I have a grid view which is bound to a SqlDataSource. There are about more than one crore records of this data source. This is because, I have allowed paging. I have a filter criteria on the same page. User selects options using checkboxes. And then on the event of filter Button, I wrote some code which builds a new SELECT command according to the filter options for SqlDataSource. And after building a new query. I wrote another line of code which is:

DataGridView.SelectCommand= FilteredQuery;

So when user clicks FilterButton, the gridview shows the filtered data. As i told you, I have allowed Paging. So after filteration, when i selects the next button of that gridview, it shows the whole data instead of Filtered one. I think this is because it postsbacks the page and binds the gridview according to the predefined SELECT command for SqlDataSource.

I tried many approaches. I used static bool variable to keep track on page_load event. It works fine then. But it still troubles when i nevigate from one page to another. When i come back to this page, it still shows the filtered data.

I have very less time. Please guide me as soon as possible. Remember, I'm totally new to dot net technologies. So any detailed guidance will be highly appreciated. Thanks.

Best Regards!

Answer 1

You have to create OnPageIndex Changed event

<asp:GridView ID="yourGrid" runat="server" AutoGenerateColumns="false" OnPageIndexChanged="yourGrid_PageIndexChanged">

And in code behind

protected void yourGrid_PageIndexChanged(object sender, EventArgs e)
{
    if (filtered) // you would have to keep track of the filtered state of your grid possibly with hidden field
    {
        DataGridView.SelectCommand = FilteredQuery;
    }
}

Answer 2

SQLDATASOURCE wont work this way. On every page change, you need to recreate your sql query. Try skipping certain rows on each page change.

Here is an example for you.

FOR PAGE - 1

SELECT * FROM (
  SELECT
    ROW_NUMBER() OVER (ORDER BY YOURKEY desc) AS rownumber,
    *
  FROM YOURTABLE
) AS ANYTHING
WHERE rownumber >= STARTING ROW and rownumber <= ENDINGROW

---

FOR EXAMPLE

 SELECT * FROM (
      SELECT
        ROW_NUMBER() OVER (ORDER BY bowzer_id desc) AS rownumber,
        *
      FROM Bowzer
    ) AS BowzerTable
    WHERE rownumber >= 10 and rownumber <= 20

FOR PAGE - 2

SELECT * FROM (
  SELECT
    ROW_NUMBER() OVER (ORDER BY bowzer_id desc) AS rownumber,
    *
  FROM Bowzer
) AS BowzerTable
WHERE rownumber >= 20 and rownumber <= 30

For PAGE - 3

SELECT * FROM (
  SELECT
    ROW_NUMBER() OVER (ORDER BY bowzer_id desc) AS rownumber,
    *
  FROM Bowzer
) AS BowzerTable
WHERE rownumber >= 30 and rownumber <= 40

You need to recreate your SQL query on every page change, as shown in example above.