C# – Gridview sorting when databinding from codebehind file

asp.netcgridviewwebforms

I am using asp.net web-form and gridview on several pages to display data. I bind gridview from codebehind file.

SO far i am able to use following code to bind datasource to gridview and also enable paging but i a facing problem to enable sorting on the same grid. Any point or help regarding how to enable paging to make it work with the below code.

I also have addition fields which are not part of this code which i use for additional functionality
onrowdatabound="GridView1_RowDataBound" onrowcommand="GridView1_RowCommand"

.ASPX File

<asp:GridView ID="GridView1" runat="server" AllowPaging="True" AutoGenerateColumns="False" DataKeyNames="ID" 
           Width="990px" BackColor="White" BorderColor="WhiteSmoke" BorderStyle="None" BorderWidth="0px" CellPadding="5" 
            Font-Names="Verdana" Font-Size="X-Small" ForeColor="Black" GridLines="Horizontal" PageSize="10" CssClass="myheader"  AllowSorting="true" 
             onrowdatabound="GridView1_RowDataBound"  onrowcommand="GridView1_RowCommand" onpageindexchanging="GridView1_PageIndexChanging" >
            <Columns>
                <asp:BoundField DataField="ID" HeaderText="ID" SortExpression="ID" />
                <asp:BoundField DataField="FirstName" HeaderText="First Name" SortExpression="FirstName" />
                <asp:BoundField DataField="LastName" HeaderText="Last Name" SortExpression="LastName" />
                <asp:BoundField DataField="Date" HeaderText="Date" SortExpression="Date"  DataFormatString="{0:yyyy/MM/dd}"/>
            </Columns>
            <FooterStyle BackColor="#CCCC99" ForeColor="Black" />
            <HeaderStyle  Height="32px" Font-Bold="True" ForeColor="White" HorizontalAlign="Left" BorderStyle="None" />
            <PagerStyle BackColor="White" ForeColor="Black" HorizontalAlign="Right" />
            <SortedAscendingCellStyle BackColor="#F7F7F7" />
            <SortedAscendingHeaderStyle BackColor="#4B4B4B" />
            <SortedDescendingCellStyle BackColor="#E5E5E5" />
            <SortedDescendingHeaderStyle BackColor="#242121" />
            <RowStyle   BorderColor="#f5f5f5" BorderStyle="Notset"/>
   </asp:GridView>

CODE BEHIND

protected void Page_Load(object sender, EventArgs e)
{

    if (!IsPostBack)
    {
        GetDetails();
    }
}   


   protected void GetDetails()
{
    string strSql = "SELECT * FROM Test_Table Order by Date Desc ";
    DataSet ds = DataProvider.Connect_Select(strSql);
    GridView1.DataSource = ds;
    GridView1.DataBind();

}

    protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    GetDetails();
}

UPDATE: Code updated to

.ASPX

OnSorting="GridView1_OnSorting"

CODE BEHIND

    protected void GridView1_OnSorting(object sender, GridViewSortEventArgs e)
{
    string strSql = "SELECT * FROM Test_Table ";
    DataSet ds = DataProvider.Connect_Select(strSql);
    DataTable dataTable = ds.Tables[0];
    DataTable dataTable = ds.Tables[0];

    if (dataTable != null)
    {
        DataView dataView = new DataView(dataTable);
        dataView.Sort = e.SortExpression + " "+e.SortDirection;
        GridView1.DataSource = dataView;
        GridView1.DataBind();
    }
}

Best Answer

You should create sorting event like this :

    protected void GridView1_OnSorting(object sender, GridViewSortEventArgs e)
    {

        //TODO write tour code here to get data from database;
         DataTable dataTable = your datatable get from your db;

        if (dataTable != null)
        {
                if (e.SortDirection.ToString() == "Ascending")
                {
                    dataView.Sort = e.SortExpression + " ASC";
                }
                else if (e.SortDirection.ToString() == "Descending")
                {
                    dataView.Sort = e.SortExpression + " DESC";
                }

            DataView dataView = new DataView(dataTable);
            dataView.Sort = e.SortExpression + " "+e.SortDirection;
            GridView1.DataSource = dataView;
            GridView1.DataBind();
        }
    }


**e.SortExpression** provides sorting column name 

**e.SortDirection** provides sorting direction like ASC or DESC.

Also you can take sort direction in view state on page

private string GridViewSortDirection
    {
        get { return ViewState["SortDirection"] as string ?? "DESC"; }
        set { ViewState["SortDirection"] = value; }
    }

private void SetSortDirection()
        {
            GridViewSortDirection = (GridViewSortDirection.ToUpper() == "DESC") ? "ASC" : "DESC";
        }

I hope above code help you.

Related Solutions

GridView sorting: SortDirection always Ascending

The problem with Session and Viewstate is that you also have to keep track of the gridview control for which SortColumn and Direction is stored if there is more than one gridview on the page.

An alternative to Session and Viewstate is to add 2 attributes to the Gridview and keep track of Column and Direction that way.

Here is an example:

private void GridViewSortDirection(GridView g, GridViewSortEventArgs e, out SortDirection d, out string f)
{
    f = e.SortExpression;
    d = e.SortDirection;

    //Check if GridView control has required Attributes
    if (g.Attributes["CurrentSortField"] != null && g.Attributes["CurrentSortDir"] != null)
    {
        if (f == g.Attributes["CurrentSortField"])
        {
            d = SortDirection.Descending;
            if (g.Attributes["CurrentSortDir"] == "ASC")
            {
                d = SortDirection.Ascending;
            }
        }

        g.Attributes["CurrentSortField"] = f;
        g.Attributes["CurrentSortDir"] = (d == SortDirection.Ascending ? "DESC" : "ASC");
    }

}

Sorting a gridview when databinding a collection or list of objects

Thank you for your answers on the sorting. I turned to LINQ to help sort dynamically. Since the grid knows whether to sort ASC or DESC, and which field, I used a LINQ Expression. The Expression performed the sorting, and then I simply bound those results to my gridview.

I suspect the jQuery method would be faster, and wouldn't require a full postback.

using System.Linq.Expressions;

public SortDirection GridViewSortDirection
{
    get
    {
        if (ViewState["sortDirection"] == null)
            ViewState["sortDirection"] = SortDirection.Ascending;

        return (SortDirection)ViewState["sortDirection"];
    }
    set { ViewState["sortDirection"] = value; }
}

protected void gridView_Sorting(object sender, GridViewSortEventArgs e)
{
    //re-run the query, use linq to sort the objects based on the arg.
    //perform a search using the constraints given 
    //you could have this saved in Session, rather than requerying your datastore
    List<T> myGridResults = PerfomSearch();


    if (myGridResults != null)
    {
        var param = Expression.Parameter(typeof(T), e.SortExpression);
        var sortExpression = Expression.Lambda<Func<T, object>>(Expression.Convert(Expression.Property(param, e.SortExpression), typeof(object)), param);


        if (GridViewSortDirection == SortDirection.Ascending)
        {
            myGridView.DataSource = myGridResults.AsQueryable<T>().OrderBy(sortExpression);
            GridViewSortDirection = SortDirection.Descending;
        }
        else
        {
            myGridView.DataSource = myGridResults.AsQueryable<T>().OrderByDescending(sortExpression);
            GridViewSortDirection = SortDirection.Ascending;
        };


        myGridView.DataBind();
    }
}

Best Answer

Related Solutions

GridView sorting: SortDirection always Ascending

Sorting a gridview when databinding a collection or list of objects

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