I’ve spent the last few days pulling my hair out over an issue with my reports rendering correctly inside and ASP.Net page and IE7. Like many companies we are preparing to roll out Internet Explorer 7 to all of the desktops. As part of that we’re doing regression testing on our applications, and in doing my tests uncovered an issue with IE7 and our BI (Business Intelligence) solution. It is an ASP.Net 2.0 page that uses the Report Viewer control to display SQL Server 2005 Reporting Services reports.
In IE6, everything has been running fine, reports rendering correctly and users happy. In testing for IE7, we found the reports only drew enough to fill up the available space inside the browser, and then stopped. No scroll bars, and if you resized the browser it did not paint the interior correctly.
The solution, as it turns out was pretty obscure. A co-worker found a thread at http://www.eggheadcafe.com/software/aspnet/27965101/re-problems-setting-webf.aspx that put me on the correct track. The solution needed three minor tweaks to our code.
First, you need to remove the DOCTYPE line from your aspx page. Yes, that’s correct, the line that is automatically inserted when you create a new page. It should look like:
<!DOCTYPE html PUBLIC “~//W3C//DTD XHTML 1.0 Transitional//EN” "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Find it and delete it.
Next, on the ReportViewer control, make sure the AsyncRendering property is set to False. When you set it to true (the default) the report did render correctly, but instead of using the entire webpage to scroll it put another scroll bar onto the report viewer itself, and you had to use it to move through your report. Our testing found having two scroll bars (one for the page and one for the report) to be a bit confusing to the users. Try it both ways though and see what works best for you, as your mileage may vary. For us, we went with False as the setting.
In examining the AsyncRendering property, I found this article on MSDN which further confirmed the need to remove the DocType: http://msdn2.microsoft.com/en-us/library/ms252090(VS.80).aspx
In the final tweak, I made sure to set the width of the ReportViewer control to 100% and removed any setting of height. This allowed the page to scale automatically to the size it needed to be.
Since this was not an intuitive fix, I’m hoping getting the word out will help others and save them the two weeks of frustration I went through.