[c#] Getting value from a cell from a gridview on RowDataBound event

string percentage = e.Row.Cells[7].Text;

I am trying to do some dynamic stuff with my GridView, so I have wired up some code to the RowDataBound event. I am trying to get the value from a particular cell, which is a TemplateField. But the code above always seems to be returning an empty string.

Any ideas?

To clarify, here is a bit the offending cell:

<asp:TemplateField HeaderText="# Percentage click throughs">
<ItemTemplate>
    <%# AddPercentClickThroughs((int)Eval("EmailSummary.pLinksClicked"), (int)Eval("NumberOfSends")) %>
</ItemTemplate>
</asp:TemplateField>

On a related note, does anyone know if there is a better way of selecting the cell in the row. It sucks putting in cell[1]. Couldn't I do cell["mycellname"], so if I decide to change the order of my cells, bugs wont appear?

why not pull the data directly out of the data source.

DataBinder.Eval(e.Row.DataItem, "ColumnName")

Just use a loop to check your cell in a gridview for example:

for (int i = 0; i < GridView2.Rows.Count; i++)
{
    string vr;
    vr = GridView2.Rows[i].Cells[4].Text; // here you go vr = the value of the cel
    if (vr  == "0") // you can check for anything
    {
        GridView2.Rows[i].Cells[4].Text = "Done";
        // you can format this cell 
    }
}

protected void gvbind_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        e.Row.Attributes["onmouseover"] = "this.style.cursor='hand';";
        e.Row.Attributes["onmouseout"] = "this.style.textDecoration='none';";
        e.Row.Attributes["onclick"] = ClientScript.GetPostBackClientHyperlink(this.gvbind, "Select$" + e.Row.RowIndex);
    }
}

Label lblSecret = ((Label)e.Row.FindControl("lblSecret"));

<asp:TemplateField HeaderText="# Percentage click throughs">
  <ItemTemplate>
    <%# AddPercentClickThroughs(Convert.ToDecimal(DataBinder.Eval(Container.DataItem, "EmailSummary.pLinksClicked")), Convert.ToDecimal(DataBinder.Eval(Container.DataItem, "NumberOfSends")))%>
  </ItemTemplate>
</asp:TemplateField>


public string AddPercentClickThroughs(decimal NumberOfSends, decimal EmailSummary.pLinksClicked)
{
    decimal OccupancyPercentage = 0;
    if (TotalNoOfRooms != 0 && RoomsOccupied != 0)
    {
        OccupancyPercentage = (Convert.ToDecimal(NumberOfSends) / Convert.ToDecimal(EmailSummary.pLinksClicked) * 100);
    }
    return OccupancyPercentage.ToString("F");
}

I had a similar question, but found the solution through a slightly different approach. Instead of looking up the control as Chris suggested, I first changed the way the field was specified in the .aspx page. Instead of using a <asp:TemplateField ...> tag, I changed the field in question to use <asp:BoundField ...>. Then, when I got to the RowDataBound event, the data could be accessed in the cell directly.

The relevant fragments: First, the aspx page:

<asp:GridView ID="gvVarianceReport" runat="server" ... >
...Other fields...
    <asp:BoundField DataField="TotalExpected" 
     HeaderText="Total Expected <br />Filtration Events" 
     HtmlEncode="False" ItemStyle-HorizontalAlign="Left" 
     SortExpression="TotalExpected" />
...
</asp:Gridview>

Then in the RowDataBound event I can access the values directly:

protected void gvVarianceReport_Sorting(object sender, GridViewSortEventArgs e)
{
    if (e.Row.Cells[2].Text == "0")
    {
        e.Row.Cells[2].Text = "N/A";
        e.Row.Cells[3].Text = "N/A";
        e.Row.Cells[4].Text = "N/A";
    }
}

If someone could comment on why this works, I'd appreciate it. I don't fully understand why without the BoundField the value is not in the cell after the bind, but you have to look it up via the control.

When you use a TemplateField and bind literal text to it like you are doing, asp.net will actually insert a control FOR YOU! It gets put into a DataBoundLiteralControl. You can see this if you look in the debugger near your line of code that is getting the empty text.

So, to access the information without changing your template to use a control, you would cast like this:

string percentage = ((DataBoundLiteralControl)e.Row.Cells[7].Controls[0]).Text;

That will get you your text!

Regarding the index selection style of the columns i suggest you do the following. i ran into this problem but i was going to set values dynamically using an API so what i did was this : keep in mind .CastTo<T> is simply ((T)e.Row.DataItem)

and you have to call DataBind() in order to see the changes in the grid. this way you wont run into issues if you decide to add a column to the grid.

 protected void gvdata_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if(e.Row.RowType == DataControlRowType.DataRow)
            {
                var number = e.Row.DataItem.CastTo<DataRowView>().Row["number"];
                e.Row.DataItem.CastTo<DataRowView>().Row["ActivationDate"] = DateTime.Parse(userData.basic_info.creation_date).ToShortDateString();
                e.Row.DataItem.CastTo<DataRowView>().Row["ExpirationDate"] = DateTime.Parse(userData.basic_info.nearest_exp_date).ToShortDateString();
                e.Row.DataItem.CastTo<DataRowView>().Row["Remainder"] = Convert.ToDecimal(userData.basic_info.credit).ToStringWithSeparator();

                e.Row.DataBind();
            }
        }

When you use a TemplateField and bind literal text to it like you are doing, asp.net will actually insert a control FOR YOU! It gets put into a DataBoundLiteralControl. You can see this if you look in the debugger near your line of code that is getting the empty text.

So, to access the information without changing your template to use a control, you would cast like this:

string percentage = ((DataBoundLiteralControl)e.Row.Cells[7].Controls[0]).Text;

That will get you your text!

If you set the attribute Visible on the asp:BoundField to False. Like this

<asp:BoundField DataField="F1" HeaderText="F1" Visible="False"/>

You will not get any Text in the Cells[i].Text property when you loop the rows. So

foreach (GridViewRow row in myGrid.Rows)
{
  userList.Add(row.Cells[0].Text); //this will be empty ""
}

But you can set a column not visible by connecting the grid to the event OnRowDataBound then from here do this

e.Row.Cells[0].Visible = false //now the cell has Text but it's hidden

The above are good suggestions, but you can get at the text value of a cell in a grid view without wrapping it in a literal or label control. You just have to know what event to wire up. In this case, use the DataBound event instead, like so:

protected void GridView1_DataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        if (e.Row.Cells[0].Text.Contains("sometext"))
        {
            e.Row.Cells[0].Font.Bold = true;
        }
    }
}

When running a debugger, you will see the text appear in this method.

use RowDataBound function to bind data with a perticular cell, and to get control use (ASP Control Name like DropDownList) GridView.FindControl("Name of Control")