[RESOLVED] Enable field sorting when gridview datasource from code behind

Ok, I'm not sure how to get this to work. I have a gridview and I've enabled paging and sorting on my gridview. I set the two fields in question to be sortable headers. Here is what I have so far:

 

// Populate GridView using data table from code behind

    private void GetData()
    {
        DataTable table = new DataTable();
        // get the connection
        string _cs = DBUtils.DBString;
        using (SqlConnection conn = new SqlConnection(_cs))
        {
            // write the sql statement to execute
            string sql = "SELECT [userid], [department] FROM [Employees] order by userid";
            // instantiate the command object to fire
            using (SqlCommand cmd = new SqlCommand(sql, conn))
            {
                // get the adapter object and attach the command object to it
                using (SqlDataAdapter ad = new SqlDataAdapter(cmd))
                {
                    // fire Fill method to fetch the data and fill into DataTable
                    ad.Fill(table);
                }
            }
        }
        GridView1.DataSource = table;
        GridView1.DataBind();
    }

// now for the code that is for sorting, I think this may be my problem.

    protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
    {
        DataTable dataTable = GridView1.DataSource as DataTable;

        if (dataTable != null)
        {
            DataView dataView = new DataView(dataTable);
            dataView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e.SortDirection);

            GridView1.DataSource = dataView;
            GridView1.DataBind();
        }
    }

// this code determines the selected sort order

    private string ConvertSortDirectionToSql(SortDirection sortDirection)
    {
        string newSortDirection = String.Empty;

        switch (sortDirection)
        {
            case SortDirection.Ascending:
                newSortDirection = "ASC";
                break;

            case SortDirection.Descending:
                newSortDirection = "DESC";
                break;
        }

        return newSortDirection;
    }

So, how do I get this sorting to work?

dataView. Sort = e. SortExpression + " " + ConvertSortDirectionToSql (e. SortDirection ); AFAIK, dv.sort= like : dataView. Sort = e. SortExpression + " Asc"

hi,

let the sorting work contains several steps:

1)set AllowSorting="True".

2)add SortExpression property in field.like:

3)define gridview sorting method.

Hope this helps

I'm using template fields not bound fields.

Ok, once I click the header, it sets the sort direction as ascending and retains that value no matter how many times I click on the header.

Hi,

You can use client side sorting mechanism. Refer the below urls which will use tablesorter & jquery for this because if we are doing it in server side we need to either fetch the data from db again or we need to keep it in session/other storage mechanism
for holding the data source of gridview won't be available on postback

http://dotnet-mcts.jecaestevez.com/2011/03/sort-aspnet-gridview-columns-using.html

http://www.iamraghuveer.com/2012/04/sorting-aspnet-gridview-control-using.html

Hope it helps

I finally figured this one out. Here's the link that helped me.

http://satindersinght.blogspot.com/2013/05/gridview-sorting-on-header-click-with.html

My relevant code sample:

 

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        List list = new List();
        if (ViewState["SelectedRecords"] != null)
        {
            list = (List)ViewState["SelectedRecords"];
        }
        foreach (GridViewRow row in GridView1.Rows)
        {
            String id = (String)GridView1.DataKeys[row.RowIndex].Value;
            CheckBox checkBox = (CheckBox)row.FindControl("chkSelect");
            if (checkBox.Checked)
            {
                if (!list.Contains(id))
                {
                    list.Add(id);
                }
            }
            if (!checkBox.Checked)
            {
                list.Remove(id);
            }
        }
        ViewState["SelectedRecords"] = list;
        GridView1.PageIndex = e.NewPageIndex;
        GridView1.DataSource = Session["objects"];
        GridView1.DataBind();
    }

    protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
    {
        GetData();
        DataTable sourceTable = GridView1.DataSource as DataTable;
        string sortingDirection = string.Empty;
        if (direction == SortDirection.Ascending)
        {
            direction = SortDirection.Descending;
            sortingDirection = "Desc";
        }
        else
        {
            direction = SortDirection.Ascending;
            sortingDirection = "Asc";
        }
        DataView sortedView = new DataView(sourceTable);
        sortedView.Sort = e.SortExpression + " " + sortingDirection;
        Session["objects"] = sortedView;
        DataView view = new DataView(sourceTable);
        GridView1.DataSource = sortedView;
        GridView1.DataBind();
    }

    public SortDirection direction
    {
        get
        {
            if (ViewState["directionState"] == null)
            {
                ViewState["directionState"] = SortDirection.Ascending;
            }
            return (SortDirection)ViewState["directionState"];
        }
        set
        { ViewState["directionState"] = value; }
    }