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Thursday, March 20, 2008

Missing Event Handlers

First, has anyone other than me noticed that it takes like 2+ minutes for Visual Web Developer to fully open and come alive? What the hell is it doing? We'll save that for another time.

So you create an Ajax Web Form. You want to put an even handler on Init of the form. How? There is no event icon in the object inspector for the document.

So you click on the Script manager and presto! you get the little lightning bolt icon.

Let's try it with a master page. We create a master and a content page and guess what? There is NO WAY to add an onInit handler to the content page. There's no script manager. If you open the .cs code file and/or double-click the page in the designer, you get a page_load function.

You can try to add one by hand, but where would you put that?....

Ok lets move on.

Slap a button on the screen, and then select the button. Wohoo! the little lightning bolt is there!

Now create a table and put in a row and a cell and put the button in there. Oops, you can no longer click the button and create event handlers, you keep getting the table. In fact the only way I have found to add a handler is to drag the button out of all the panels, tables, etc., and edit it's event handlers, then drag it back into it's table cell and hope it all works.

This is goofy.

The solution is to create all components you need to access the events of outside all tables tables or panels, create the event handlers and then drag (or cut/paste) the objects back into the table or panel.

Tuesday, March 11, 2008

IE7 Displays Blank Page: Firefox OK.

When I try to browse to my website, which contins an ASP page, I get a blank page for IE7, yet all is well for Firefox.

View Source in Firefox gives the normal page, while IE just shows this:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<META http-equiv=Content-Type content="text/html; 

The page had some Flash embedded, but I get this result even after removing it. Im heading for "Clearly, IE is BROKEN". What MORON would have a browser substitute a blank page without any kind of error or warning message?

I found the solution after pulling an all-nighter on it.

This had to do with a database error: here's what happened. For some reason the database error was NOT getting reported to the browser, it just got a blank page.

I store the data from every hit in a table for diagnosing problems. That data element was a varchar(250), which up until now was more than adequate. The string from a firefox hit comes in at 163 and looks like this:

03/10/2008 16:24:14 Mozilla Netscape 5.0 (Windows; en-US) Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20080201 Firefox/ en-US Win32

However IE7 sends this for the exact same page:

03/10/2008 16:24:14 Mozilla Microsoft Internet Explorer 4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.590; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022) Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.590; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022) undefined Win32

That's a whopping 380 characters, which caused a string length error on my SQL insert command.

I still don't understand why in hell it returned a completely blank page to IE without any errors listed but whatever, I'm re-doing the whole site in ASP.NET anyways.

The ANSWER: I had to stretch the database column where I'm storing the hit data strings to 1000 characters. That ought to hold me until IE8 SP2 at least.

Thursday, March 6, 2008

ASP.NET: Uploading Files

This is so easy. Drop a FileUpload object onto your AJAX web page. Drop in a button.

In the button event handler, do this:

//get the path to the UPLOADS directory in your webbserver
        string path=Server.MapPath(@"~\Uploads"); 

//create the full path+file name
        string SaveAsName=path+@"\"+FileUpload1.FileName;


//This is the bulk of it right here.
        catch(Exception err)
            Label1.Text = err.Message;

That's it. The FileUpload object hands you all the data and functionality you need. Of course I could have checked to see that the file being uploaded is of a certain size or type, but this quick tutorial is just about the basics.

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