Hiding columns ion GridView or ListView

rah132 · February 26th, 2013, 04:37 PM

Imar:

In your book (Page 530) you say "Additionally, you can tweak these controls to hide specific columns, ...".
I have had no luck hiding columns in a GridView. I have tried adding

Code:

e.Row.Cells[0].Visible=false;

to the RowCreated event but this results in the column not being rendered.

Several blogs talk about the fact that Microsoft decided (starting with Visual Studio 2008) that hiding columns was a security risk at no longer renders any cell that is marked as "visible = false" and consequently the data in that column is not hidden - it is deleted!

One blog suggests that you can set "itemstyle-css" to a "hiddencol" attribute that you define in a style sheet as "display: none;". To do this with a databound GridView you need to set autogeneratecolumns to false so that you can add the "itemstyle-css" to each BoundField in Markup view. However, this does not work.

Do you have any suggestions? Is it possible if I use a ListView instead?

Imar · February 26th, 2013, 05:07 PM

Quote:

Several blogs talk about the fact that Microsoft decided (starting with Visual Studio 2008) that hiding columns was a security risk at no longer renders any cell that is marked as "visible = false" and consequently the data in that column is not hidden - it is deleted!

This has always been the case. Visible=False means *server-side visibility*. Something that's not visible at the server is never sent to the browser.

Why do you want to hide it client still, but still include it in the HTML?

The other tip should work: add a CSS class to the column and then hide it using CSS.

Imar

rah132 · February 26th, 2013, 06:50 PM

Imar:

The reason that I want to hide a column is that I am developing a multi-tenant application. Every table ion my DB contains a TenantId column. My EntityDataSource has a "where" clause that filters on the TenantId. Consequently the TenantId must be included in the data and ends up being displayed.

I have solved the problem in the hour or two since I sent you the question. The ItemStyleCssClass = "hiddencol" which is defined as "display: none;" works for the data but does not hide the GridView column heading. Because the headings are generated dynamically it is not possible to assign a CssClass to them. To hide(delete) the column heading I placed the following code in the RowCreated event:

Code:

If (e.Row.RowType = DataControlRowType.Header)
           {
            e.Row.Cells[0].Visible = false;
           }

Once again, thank you for your response. You are very generous with your time.

Robin

Imar · February 27th, 2013, 06:57 AM

Quote:

Consequently the TenantId must be included in the data and ends up being displayed.

This isn't true. You don't need a field in a Select statement or a column to include it in a Where clause.

If you still need the TenantId available after a postback, just add it to the DataKeyNames attribute, This way, it's stored and encrypted in ViewState and you don't need to mess with hidden but not not hidden columns.

Cheers,

Imar