BUG: Setting Server Control's InnerHtml forces Constructore to be called.

[johndoe]

While creating a shopping cart application I noticed a strange bug which resulted in the Constructor and everything being called twice. I was using Inherited classes ClassShowProduc ts inherited TemplatePage which inherited System.Web.UI.P age which I thought was the problem so I spent all day recoding everything so that ClassShowProduc ts was inherited from System.Web.UI.P age. Then I found out that it still happend.
I then quickly narrowed it down to one line of code in Page_Load(

i have a server control <td id="tdMainConte nt" runat="server"> and in my Page_Load i go
tdMainContent.I nnerHtml = render_MainBody (); // returns a massive string

if i go string MainContent = render_MainBody (); it works fine
however the minute I try setting tdMainContent.I nnerHtml it borks and basically when Page_Load ends the class constructor is called and goes through everything again, Class Constructor, OnInit, InitializeCompo nent, Page_Load etc.

The Length of the string is 4927 bytes and is Valid HTML Content.
After doing some tdMainBodyConte nt.InnerHtml = string('c', randomlenghs);
it does not appear to be "content length" related I am thinking it may be related to complexity of the structure of the HTML. I have checked the HTML and it is W3C Valid and since it is generated by XML/XSLT i know that there will not be any missing/open tags . I am at a loss

Okay. That sound's reasonable. So hopefuly if it comes back i should just
look for an <img tag without any empty src specified. I wish i would have
seent he pattern before. Thanks for everything

"Steven Cheng[MSFT]" <v-******@online.m icrosoft.com> wrote in message
news:UM******** ********@cpmsft ngxa06.phx.gbl. ..

Hi,
Thanks for your followup. I've done some further tests on different
machines and finally found out the root cause of this issue. The problem
is
caused by the "Default Documents" set in the VirtualDirctory , the by
default an IIS Virtual Directory's Default Documents are "default.ht m",
"index.htm" , "default.as p", "iisstart.a sp". And maybe has the
"default.as px" . The "Default Documents" means when you didn't specify a
certain file name in a url , such as
"http://localhost/WebApplication5/" then, the IIS will search in the
default documents, if any one find then redirect to that certain file. And
also if you used some certain relative path url to refer a no file
specified url such as
<img src=""/> (if this image tag is in a page in the virutal directory's
root folder) then, the default document will also be called.

And from your code in the string you set in the page_load
private void Page_Load(objec t sender, System.EventArg s e)
{
tdMainBodyConte nt.InnerHtml = "......."
}
There contains an "<img src=\"\">", yes? You may have a check, then, that
cause the IIS search for the default documents and you can check the
WebApplication5 's virual directory's Default Document attributes to see
whether the "Default.as px" is in the list, I'm sure it is in that list ,
and that's why the Default.aspx is caused again. So this problem can be
repro event if we hard code a <img src=""> tag in the aspx page. And I've
add one of my repro page named "MyReproPag e" in the modified project I've
attached in this message. Please check it out.

In addition, as for my last reply( I mentioned that I didn't repro this
problem). That's because I firstly test in a machine(WINXP) on which the
IIS by default didn't add the "Default.as px" into the default documents.
However, when I tried testing on a WIN2003 server machine,where by default
"Default.as px" is added in the virual directory's default documents, then
I
was managed to repro this. Seems a bit lucky:).

Anyway, please check out the above results. If you found any difference
from my result or have any further questions, please feel free to post
here.


Regards,

Steven Cheng
Microsoft Online Support

Get Secure! www.microsoft.com/security
(This posting is provided "AS IS", with no warranties, and confers no
rights.)

Get Preview at ASP.NET whidbey
http://msdn.microsoft.com/asp.net/whidbey/default.aspx