GridView without DataSourceControl DataSource

written by Ryan Olshan on Sunday, January 22 2006

If you're like me and converting a .NET 1.1 application to 2.0, and aren't using a DataSourceControl DataSource just yet but need to enable sorting and paging, you might run into the following exceptions:

When changing the page:

The GridView 'GridViewID' fired event PageIndexChanging which wasn't handled.

When clicking a column name to sort the column:

The GridView 'GridViewID' fired event Sorting which wasn't handled.

As a result of not setting the DataSourceID property of the GridView to a DataSourceControl DataSource, you have to add event handlers for sorting and paging.

    
    <asp:GridView ID="gridView" AllowPaging="true" AllowSorting="true"
        OnPageIndexChanging="gridView_PageIndexChanging" OnSorting="gridView_Sorting"
        runat="server" />
 
    private string GridViewSortDirection
    {
        get { return ViewState["SortDirection"] as string ?? "ASC"; }
        set { ViewState["SortDirection"] = value; }
    }
 
    private string GridViewSortExpression
    {
        get { return ViewState["SortExpression"] as string ?? string.Empty; }
        set { ViewState["SortExpression"] = value; }
    }
 
    private string GetSortDirection()
    {
        switch (GridViewSortDirection)
        {
            case "ASC":
                GridViewSortDirection = "DESC";
                break;
 
            case "DESC":
                GridViewSortDirection = "ASC";
                break;
        }
 
        return GridViewSortDirection;
    }
 
    protected void gridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        gridView.DataSource = SortDataTable(gridView.DataSource as DataTable, true);
        gridView.PageIndex = e.NewPageIndex;
        gridView.DataBind();
    }
 
    protected DataView SortDataTable(DataTable dataTable, bool isPageIndexChanging)
    {
        if (dataTable != null)
        {
            DataView dataView = new DataView(dataTable);
            if (GridViewSortExpression != string.Empty)
            {
                if (isPageIndexChanging)
                {
                    dataView.Sort = string.Format("{0} {1}", GridViewSortExpression, GridViewSortDirection);
                }
                else
                {
                    dataView.Sort = string.Format("{0} {1}", GridViewSortExpression, GetSortDirection());
                }
            }
            return dataView;
        }
        else
        {
            return new DataView();
        }
    }
 
    protected void gridView_Sorting(object sender, GridViewSortEventArgs e)
    {
        GridViewSortExpression = e.SortExpression;
        int pageIndex = gridView.PageIndex;
        gridView.DataSource = SortDataTable(gridView.DataSource as DataTable, false);
        gridView.DataBind();
        gridView.PageIndex = pageIndex;
    }

Comments

Giuliano Valentino on on 1.26.2006 at 8:37 AM

Thanks for the code above. It's actually a relief not to get the error anymore!

The problem now is that when I click on my header name (after setting up a sort expression) it does not change the sort order. The event fires but the page looks the same as it did before.

As well, when I select a new page from the index on the bottom it displays the error message I set up to return where there are no records that march a query.

I'm sure there is something simple I'm missing here. Is there anything else I should provide?

Thanks!
Ryan Olshan on on 1.26.2006 at 9:02 AM

From your comment, it sounds like the GridView isn't binding to the DataSource correctly or not binding at all. Is your code an identical match to what I have above? Could you post your code, or if it's too large e-mail it to Ryan(dot)Olshan(at)strongtypes(dot)com?
Giuliano Valentino on on 1.26.2006 at 9:13 AM

I'm emailing you the code in a couple of seconds.
Ryan Olshan on on 1.26.2006 at 9:32 AM

Just replied. The line in the gridView_Sorting method in your code that concatinates the SortExpression should look like m_DataView.Sort = e.SortExpression & " " & ConvertSortDirectionToSql(e.SortDirection) since you are coding in VB.NET.
Patrick Fomin on on 1.31.2006 at 11:49 AM

I still dont get the sorting to work (paging works), i have the same problem as Giuliano. I copied your code and it just dosent work. Here is the the code that is dealing with it:

<asp:GridView ID="usergrid" runat="server" AutoGenerateColumns="False" DataKeyNames="UserName" AllowSorting="True" AllowPaging="True" CellPadding="4" ForeColor="#333333" GridLines="None" PageSize="10" OnPageIndexChanging="usergrid_PageIndexChanging" OnSorting="usergrid_Sorting" OnSorted="usergrid_Sorted">

MembershipUserCollection mUsers;

protected void Page_Load(object sender, EventArgs e)

{

mUsers = Membership.GetAllUsers();

usergrid.DataSource = mUsers;

if (!this.IsPostBack)

{

usergrid.DataBind();

}

}

public void usergrid_PageIndexChanging (object sender, GridViewPageEventArgs e)

{

usergrid.PageIndex = e.NewPageIndex;

usergrid.DataBind();

}

public void usergrid_Sorting (object sender, GridViewSortEventArgs e)

{

DataTable m_DataTable = usergrid.DataSource as DataTable;

if (m_DataTable != null)

{

DataView m_DataView = new DataView(m_DataTable);

m_DataView.Sort = e.SortExpression + " " + e.SortDirection;

usergrid.DataSource = m_DataView;

usergrid.DataBind();

}

}

public void usergrid_Sorted (object sender, EventArgs e)

{

Response.Write("Sorting by " +

usergrid.SortExpression.ToString() +

" in " + usergrid.SortDirection.ToString() +

" order.");

}
Ryan Olshan on on 2.02.2006 at 4:00 AM

Hi Patrick,

When you say you can't get sorting to work, what happens? Does it not work at all? Is an exception raised? Also, do you have a value for the SortExpression property of the column you want to sort assigned a value?
huzefa on on 2.07.2006 at 8:06 PM

Hi Rolshan....

Wel I have been trying to get the sorting event to work but in vain. even made the change as u mentioned above about the '&', since i too am coding in VB.Net. the paging works great (although after re-entering data into the dataset of the gridview ...) but just cant get the sort feature to work ..... if u cld look at the code and see wat was wrong, then i wld be obliged ..... thanks a lot in advance !!!

ps: pls .... i need this very urgently ..... reply here or mail me at htinwala@gmail.com

'code starts here

Protected Sub gvSvAPageIndexChanging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)

gvSvA.PageIndex = e.NewPageIndex

gvSvA.DataSource = ws.gvSvAselect(ddlLoc.SelectedValue, ddlMvmtLoc.SelectedValue, ddlNextAction.SelectedValue, _

ddlMvmtStatus.SelectedValue, ddlBatchNo.SelectedValue, ddlSeg.SelectedValue, _

ddlPL.SelectedValue)

gvSvA.DataBind()

End Sub

Private Function ConvertSortDirectionToSql(ByVal sortdirection As SortDirection) As String

Dim msortdirection As String = String.Empty

Select Case sortdirection

Case sortdirection.Ascending

msortdirection = "ASC"

Return msortdirection

Exit Function

Case sortdirection.Descending

msortdirection = "DESC"

Return msortdirection

Exit Function

End Select

Return msortdirection

End Function

Protected Sub gvSvASorting(ByVal sender As Object, ByVal e As GridViewSortEventArgs)

Dim mdatatable As DataTable = CType(gvSvA.DataSource, DataTable)

If Not (mdatatable Is Nothing) Then

Dim mdataview As DataView = New DataView(mdatatable)

mdataview.Sort = e.SortExpression & " " & ConvertSortDirectiontoSql(e.SortDirection)

gvSvA.DataSource = mdataview

gvSvA.DataBind()

End If

End Sub
Ryan Olshan on on 2.08.2006 at 9:46 PM

huzefa,

What does your GridView code look like?

Ryan
huzefa on on 2.13.2006 at 10:16 PM

Hi Rolshan....

real sorry for not getting back immediately ....

anyways, as i said earlier, i am binding my gridview to a dataset which i pass from a webservice.... so the binding is done at the server side in VB.Net ... thru these 2 lines ...

gvSvA.DataSource = ws.gvSvAselect(ddlLoc.SelectedValue, ddlMvmtLoc.SelectedValue, ddlNextAction.SelectedValue, ddlMvmtStatus.SelectedValue, ddlBatchNo.SelectedValue, ddlSeg.SelectedValue, ddlPL.SelectedValue)

gvSvA.DataBind()

on the Aspx page all i write for the gridview is :

<asp:GridView ID="gvSvA" runat="server" OnPageIndexChanging="gvSvAPageIndexChanging"

OnSorting="gvSvASorting">

<Columns>

<asp:CommandField ShowSelectButton="True" />

</Columns>

</asp:GridView>

But i am also using themes and have an entry in a skin for gridviews in general which is :

<asp:GridView runat="server" AllowPaging="True" AllowSorting="True" CellPadding="4" GridLines="None" HorizontalAlign="Center" Font-Size="X-Small" Font-Names="Arial" ForeColor="Navy">

<PagerSettings Mode="NumericFirstLast" />

<HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />

<FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />

<RowStyle BackColor="#EFF3FB" />

<SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />

<EditRowStyle Font-Names="Arial" Font-Size="X-Small" BackColor="#2461BF"/>

<AlternatingRowStyle BackColor="White" />

<PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" /></asp:GridView>

Hope you can figure something out of this ...........

Thanks a lot in advance ...........

Huzefa.
Ryan Olshan on on 2.14.2006 at 9:54 AM

Huzefa,

Since you are using a DataSet, you will need to modify the sorting code to something like I have below, as the one I have posted uses a DataTable.

protected void gridView_Sorting(object sender, GridViewSortEventArgs e)

{

DataSet m_DataSet = gridView.DataSource as DataSet;

if (m_DataSet != null)

{

DataView m_DataView = new DataView(m_DataSet.Tables[0]);

...

}

}
gradiation on on 3.02.2006 at 3:09 PM

Any chance someone has an example for editing rows?
vidyashan on on 3.08.2006 at 10:40 AM

Bothing paging and sorting works - But if you look closely in sorting Descending order is never fired. First time when you click on the header portion if takes Ascending - and also the second time.

Anybody noticed this??

Sri
rolshan on on 3.08.2006 at 10:55 AM

Hi Sri,

Soon after posting that I noticed that sorting didn't work in both directions. There is now sample code and a live working examples of this in both VB.NET and C#, where sorting working in both directions. See the following blog entries:

VB.NET - http://blogs.strongcoders.com/blogs/ryan/archive/2006/02/23/575.aspx

C# - http://blogs.strongcoders.com/blogs/ryan/archive/2006/02/18/555.aspx

Ryan
BenJones on on 3.28.2006 at 10:45 AM

I came across this trying to do an admin panel for membership and profiles. I had users first and last name stored in the profiles. Since the default sql profile provider doesn't have a method that I'm aware of, I load the username, and "lastname, firstname" field into a datatable and bind that to a gridview. This needs to act like all the other gridviews with sorting and paging, which is where your code has been helpful. But the sorting doesn't hold when pages are changed. I made some mods and changed it.

Source: http://www.learnasp.com/freebook/learn/cs_GridViewSortingNoDataSourceControl.aspx

1) I put the PopulatePublishersGridView(); in the Page_Init event method. I believe this calls the method once instead of everytime the page loads. The gridview control stores the information on subsequent page loads in the viewstate.

2)I would think that after the GridView control's DataSource is set to a DataTable it would be saved in the ViewState. So if you changed the DataTable in the GridView's DataSource, those changes would be reflected in the GridView and saved in the ViewState.

That means if you sort the table, thus changing the table, then rebind it, thus saving it to the GridView, then those changes would also be reflected in the ViewState so when you change pages of the GridView control, the info would still be sorted.

It doesn't seem to work that way. Maybe I'm missing something more fundamental in how these things work. But I worked around this by saving the sort field in the ViewState and sorting in the PageIndexChanged event method.

3) Just like the GridViewSortDirection, I saved a GridViewSortExpression.

    private String GridViewSortExpression
    {
        get { return ViewState["SortExp"] as String ?? ""; }
        set { ViewState["SortExp"] = value; }
    }

4)In the "gridViewPublishers_Sorting" event method, I added:

     GridViewSortExpression = e.SortExpression;

5)To keep from having redundant code in the Sorting and PageIndexChanging event methods, I created a function for the sorting:

     protected DataView SortTable (DataTable dt)
    {
        DataView dv=new DataView();
        if (dt != null)
        {
            dv = new DataView(dt);
            if(GridViewSortExpression != "")
            {
                dv.Sort = GridViewSortExpression + " " +
                GridViewSortDirection;
             }
        }
        return dv;
    }

6) I then added:

    gridView.DataSource = SortTab
nirmal on on 4.09.2006 at 7:16 AM

hi

i have been using strongly typed datatable as a datasource for the grid view. What i have to do is to sort the gridview on click of buttons located on different location on the page.This i have done by sorting the table itself by using the select method of the datatable and rebinding it to the gridview.so far so good!!.

I also have added a checkbox in the templete column of the gridview.This checkbox changes the value from 0 to 1 or from 1 to 0 in the database.I have bounded this checkbox in the gridviews rowbound event.

My problem is that when i try to go to next page (I have allowed paging) a error is thrown

on this line of binding checkbox

int intEventId = (int)MyEventHistoryGridView.DataKeys[e.Row.DataItemIndex].Value;

it says dataitem index is out of bounds.

prior to binding my checkbox to a datasource there was no problem

can you help .i am very new to programming.
Uday Hebbar on on 4.18.2006 at 12:33 PM

Hi Ryan:

Firstly.. Thanks for your excellent work..

I think I have this working if I remove this sentence (Using VB Version with data table)

If Not Page.IsPostBack

Can you help me get sorting working with this piece of code there..

Thanks
Ryan Olshan on on 4.18.2006 at 1:16 PM

Hi,

You might want to check out the live examples:

C# - http://blogs.strongcoders.com/blogs/ryan/archive/2006/02/18/555.aspx

VB.NET - http://blogs.strongcoders.com/blogs/ryan/archive/2006/02/23/575.aspx

HTH,
Ryan
Uday Hebbar on on 4.18.2006 at 2:02 PM

Ryan I checked out the examples and the VB Net example does not have the If Not Page.IsPostBack
Ian Pollard on on 4.19.2006 at 5:44 AM

Ryan,

When I tried this the eventargs param e in gridView_Sorting method contained the following values:

SortExpression = 'Ascending'
SortExpression = 'ASC'

????
Ryan Olshan on on 4.19.2006 at 1:11 PM

Hi Uday,

You need to bind to the data source on postback.

HTH, Ryan
Ryan Olshan on on 4.19.2006 at 1:12 PM

Hi Ian,

Could you provide a little more background information on your issue?

Thanks. Ryan
Norma on on 4.19.2006 at 9:27 PM

Hi Ryan,

I'm stuck at stage one! I cannot get the sorting event to fire!

I'm working in VB.Net. I've added the OnSorting event handler to the aspx file as you suggested above.

I don't assign a datasource to the GridView via the design interface, but do it in my code in the Page_Load Event:

        If Not Page.IsPostBack Then
            myDS = al.dlGet_All_Budgets("vch_Code")
            GridView1.DataSource() = myDS
            GridView1.DataBind()
        End If

This successfully displays the GridView with data.

In the .aspx.vb file I have the following statement in my GridView1_Sorting Event:
Label2.Text = "SORTING!"

I've put a breakpoint on this line and the breakpoint is never reached and the Label2 display never changes when I run the code and click madly all over the grid!

I'd be so grateful if you can tell me where I'm going wrong. It's driving me nuts!

Thanks - Norma.
anowak on on 4.19.2006 at 9:35 PM

Hi Ryan,

This is a great article although I am having trouble with the custom paging. I have setup a stored procedure to do my paging so that I only get the amount of data I need. I can currently do this using an ObjectDataSource. The ObjectDataSource has a method SelectCountMethod which tells the gridview how many items are expected.

Now how would I do this using code behind without the DataSourceObject. The old DataGrid control used to have a property VirtualItemCount although they seem to have got rid of this in the GridView.

Any Ideas
Derek Young on on 5.03.2006 at 9:46 AM

Hi, Guys,

Could you please help me find what's issue for my code? It's never worked. Somehow it is DataAdapter and GridView.DataSource never related I think. Here is the code:

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            MixDesignTableAdapter dsM = new MixDesignTableAdapter();

            GridView1.DataSource = dsM.GetData();
            GridView1.DataBind();
        }
    }

    protected void GridView_Sort(object sender, GridViewSortEventArgs e)
    {
        DataSet mDataSet = GridView1.DataSource as DataSet;

        if (mDataSet != null)
        {
            DataView mDataView = new DataView(mDataSet.Tables[0]);
            mDataView.Sort = e.SortExpression + " " + ConvtSortDir2SQL();

            GridView1.DataSource = mDataView;
            GridView1.DataBind();
            errMsg.Text = e.SortExpression.ToString() + " | " + e.SortDirection.ToString();
        }
    }
It seems app never goes into if block, i.e. mDataSet is NULL.

Help, please help me! Thanks a lot!!!

DY
Ryan Olshan on on 5.03.2006 at 9:53 AM

Hi,

Try removing the if (!IsPostBack).

HTH,
Ryan
Derek Young on on 5.03.2006 at 10:11 AM

Hi, Ryan,

Thanks for your quick response.
I tried to remove postback, but it still just fresh and not do sorting. I have a label show some text in if block, it seems still not goes into. Have any idea, suggestion?
Thanks,

DY
Ryan Olshan on on 5.03.2006 at 5:19 PM

DY,

How does your code compare to the example at http://blogs.strongcoders.com/blogs/ryan/archive/2006/02/18/555.aspx?

Ryan
DK on on 5.28.2008 at 8:16 AM

Thanks a Lot ...
babu kumarasamy on on 6.28.2008 at 12:42 AM

Hi,

I am using only page not sorting. I don't to use viewstate.

In this statement I got

Object reference not set to an instance of an object.

System.Type type = grdBasicSearchMaster.DataSource.GetType();

protected void grdBasicSearchMaster_PageIndexChanging(object sender, GridViewPageEventArgs e)

{

System.Type type = grdBasicSearchMaster.DataSource.GetType();

DataTable m_DataTable = grdBasicSearchMaster.DataSource as DataTable;

grdBasicSearchMaster.DataSource = m_DataTable;

grdBasicSearchMaster.DataBind();

grdBasicSearchMaster.PageIndex = e.NewPageIndex;

}

Thanks in advance.
dhireshjawale on on 8.08.2008 at 7:44 AM

Thanks a lot

this is very good article that i had run without error.
LifeShines on on 12.18.2008 at 3:21 AM

Thanks alot for this wonderful post! This is really very helpful.

Great work!

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