Hiding columns in GridView

[RobertTheProgrammer]

Hi all,

Hopefully this one is rather simple. I just haven't been able to figure it out.

On my GridView I have some hidden key columns which I've hidden by using tha attribute Visible="false" in the TemplateField declaration. This column is later used as an UpdateParameter field.

Now if I leave the field as Visible="true", everything works fine and down in my C# code, I can easily access the UpdateParameter field with e.Command.Parameters[0].Value. However, when I set Visible to false, the call to e.Command.Parameters[0].Value always returns null.

So how can I hide this column from the users, but still use it as a parameter field?

Thanks for any assistance.

Robert

[Frinavale]

Hi all,

Hopefully this one is rather simple. I just haven't been able to figure it out.

On my GridView I have some hidden key columns which I've hidden by using tha attribute Visible="false" in the TemplateField declaration. This column is later used as an UpdateParameter field.

Now if I leave the field as Visible="true", everything works fine and down in my C# code, I can easily access the UpdateParameter field with e.Command.Parameters[0].Value. However, when I set Visible to false, the call to e.Command.Parameters[0].Value always returns null.

So how can I hide this column from the users, but still use it as a parameter field?

Thanks for any assistance.

Robert

I ran into the same problem once.
It's because when you user the .NET Visible=False the field is never rendered in browser...therefore when it comes back to the server and you try to access it there isn't anything there.

What I've done is used CSS to hide the column.
I set the CssClass of the item to be the Css class "noShow"
eg:

<asp:BoundField HeaderText="theIndex" DataField="theIndex">
     <ItemStyle CssClass="noShow" Width="0px" />
     <HeaderStyle CssClass="noShow" Width="0px" />
  </asp:BoundField>
 

Where my 'noShow" Css class was

.noShow
{
     display:none;
}
 

-Frinny

[RobertTheProgrammer]

Works beautifully. Thanks!

Robert

[RobertTheProgrammer]

One anomaly I noticed with this idea… it doesn’t seem to hide the FooterTemplate columns. I’ll continue to try to figure it out, but if you have any clues, please let me know.

Robert

[RobertTheProgrammer]

DOH! I feel like a doofus.

<FooterStyle CssClass="noShow" Width="0px" />

Solved my problem.

Robert

[Frinavale]

DOH! I feel like a doofus.

<FooterStyle CssClass="noShow" Width="0px" />

Solved my problem.

Robert

Don't feel too bad, it took me a while to even think about using CSS to format the look of my GridView.

-Frinny

[RobertTheProgrammer]

Okay, here's one that's similar, but I haven't been able to solve.

I want to dynamically hide the columns. In other words, during the page_load I get information about the current user, so later (on Page_Load, OnPageRender, OnRowDataBound-- I'm not sure) I want to selectively hide some columns from the user based upon information I'd earlier gathered during the page_load. I can't do this directly in the ASP code, so I'm assuming I'll do it down in the C# code by setting the Itemstyle, Headerstyle and Footerstyle of the TemplateField.

How does one do this? I've been trying for the last two hours to figure it out, but I'm at a loss.

Robert

[Plater]

You can either do a post process after the data has been loaded into the columns or you can do something in the RowDataBound event.

As for the original problem, seems like you can access the row directly from like mygridview.Rows[<whatever>] and get the value of the hidden column. In the click events (and others) you are usualy given the row index value so you can find the correct row and get the value from your hidden column through that method.

[Frinavale]

Okay, here's one that's similar, but I haven't been able to solve.

I want to dynamically hide the columns. In other words, during the page_load I get information about the current user, so later (on Page_Load, OnPageRender, OnRowDataBound-- I'm not sure) I want to selectively hide some columns from the user based upon information I'd earlier gathered during the page_load. I can't do this directly in the ASP code, so I'm assuming I'll do it down in the C# code by setting the Itemstyle, Headerstyle and Footerstyle of the TemplateField.

How does one do this? I've been trying for the last two hours to figure it out, but I'm at a loss.

Robert

It's probably easiest in your RowDataBound event.

Protected Sub MyGridView_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GV_MyGridView.RowDataBound
 
     If myUser.IsAllowedToViewMyFirstColumn() = False Then
         e.Row.Cells(0).CssClass = "noShow"
     End If
End Sub
 

Protected Void MyGridView_RowDataBound(Object sender,System.Web.UI.WebControls.GridViewRowEventArgs e) 
{
     If (myUser.IsAllowedToViewMyFirstColumn() == False)
     {     e.Row.Cells[0].CssClass = "noShow";}
}
 

-Frinny

[RobertTheProgrammer]

Okay, you learn something new every day. I had assumed-- falsely apparently-- that the OnRowBound event would only affect the specific row on which it was called. I needed to hide the header and footer as well and since these are not necessarily bound (my assumption-- maybe they are), it would not fire the OnRowBound event. But it works as you describe.

Many thanks for the responses.

Robert