Paul Wilson's .NET Blog

Paul,
I compared Master Pages control ASP.NET 1.x to ASP.NET 2.0 check it out:

http://ipattern.com/simpleblog/PermLink.aspx?entryid=22

Let me know what you think, Maxim

Let's say at the top-most MasterPage I want to expose the EncType of the Form so my image upload UserControl can set it and set it to accept user uploaded files. For the life of me I couldn't get FindControl to work (is string matching based on the ID the best way? what if the ID changes? if every page has to have a form, shouldn't we be able to find it by the type rather than by its string id?) My current hack in the UserControl is:

((HtmlForm)this.Parent.Parent.Parent).Enctype = "multipart/form-data"; // HACK

That _roughly_ translates to UserControl.AspxPage.Region.ContentContainer.

Depending on whether or not the UserControl is used inside of MasterPages or on a normal Page, that syntax will break.

I've tried adding a property to the top-level MasterPage so I can restrict my UserControl to the Form's EncType only:

public string FormEncType
{
get { return ((HtmlForm)Nobugform1).Enctype; }
set { ((HtmlForm)Nobugform1).Enctype = value; }
}

But I can't get a refernce to the top most page. I'm all about using the following syntax to pass just the HtmlForm into my UserControl so it can work in or out of MasterPages:

uc.TopLevelForm = Page.Form;

or

uc.TopLevelForm = Page.Master.Form;

but those don't work for various accessbility reasons.

Yes, I've tried looping through the Controls collection and looking for a Control of type HtmlForm. As of this writing, my two posts to the Asp.Net forums are still unanswered:

http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=439907

Ideas? I hope its just something simple I'm overlooking.

- Ron

Andy Smith at metabuilders.com has some code that exposes the top most HtmlForm Control:

http://www.metabuilders.com/Tools/FileUpload.aspx

My this.Parent.Parent hack seems to be crude but correct. His EnsureEncType function offers a more robust way of locating the HtmlForm Control.

- Ron

You should be able to loop through the page's controls and find the HtmlForm without any problem -- just make sure you are recursively looping through each control's child controls as well!

Thanks, Paul Wilson

Hi,

I can't seem to get this to work, I believe my problem is I don't have a control named <control id>_Template on my page

Could you email me if you have a solution to this?

gabrielhesse @ hotmail.com

Turn on tracing to see what you can "find" -- it will be the master, not one of the regions.

Does this work with sub proceedures as well? I am trying to call a sub proceedure located in my template from my implimenting page. Any ideas?

Where does this code go...on the template page? or on the page using the template? When I add it to the page using the template I get an error saying MyTemplate is not defined...my class is called MyTemplate

For Instance I have this in my template code behind...

Public Class MyTemplate
Inherits System.Web.UI.UserControl

as my class declaration..along with all the other proper stuff in there...

Now when I put the code you gave us above


Private ReadOnly Property Master() As MyTemplate
Get
Return CType(FindControl("mstrPage_Template"), MyTemplate)
End Get
End Property


Into my template code behind...either it doesnt work..or I don't know how to reference it...

When I put it into my page code I get MyTemplate not defined..

When I use it with your code in my template page...then try to call a sub procedure (located in my template code behind) called ButtonLib() it doesn't work..no matter how I preface: MyTemplate.ButtonLib(), Master.ButtonLib() etc...just don't know how to call it.

You put this code in the page itself, or in a base page if you are using that approach. If MyTemplate is not defined then either its not compiled or you have the namespace/class name incorrect. I notice you are using VB, and that automatically prepends the name of your project to all your namespace/class names, unless you change this setting in the project file. I can't think of anything else.