VB.NET if button1 caused post back then....

Question

Hi folks,

I have a situation where I need to ignore parts of page load sub inside a isPostback = true. Basically inside the isPostBack I want something like if button1 caused postback.... do this else do this...

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    If IsPostBack = True Then

        If TextBox1.Text <> String.Empty Then

            CheckDate()
        End If

    End If


End Sub

Answer 1

You should probably not have all this going on inside the Page_Load event. Instead, you should be handling events for each control that can cause a postback. This helps with code clarity, and ease of maintenance, not to mention better control in the first place.

Here's a nice brief blog entry I found on the subject: http://www.sitepoint.com/blogs/2007/01/21/page_load-is-evil/

Incidentally, handling events is much different in ASP.NET than in other environments, My guess, just based on the fact that you're trying to accomplish this in the Page_Load event is that you're not yet "getting" the event-driven programming model. (If I'm wrong, I apologize, I don't mean to be insulting).

If I'm right, however, once you get used to it, it's going to be a lot simpler for you than things were in the classic ASP days, for example, where you had to do things like try to figure out which button was clicked. Here's another nice article to explain this further: http://articles.sitepoint.com/article/driven-asp-net-development-c

Answer 2

It's hard to see this as a good idea. From the short snippet you posted, it looks like what you really need is a Validation control attached to your textbox.

Answer 3

Have a look at the POSTed items. You should see some sort of reference to that button in there. IIRC, if it was clicked, you will see some sort of reference in there, and if it wasn't it wouldn't be in there. I had this same problem a while a ago and that's how I circumvented loading some stuff.

Answer 4

I think what you need is the reference to the control name which triggered the postback.

http://geekswithblogs.net/mahesh/archive/2006/06/27/83264.aspx

Implement the solution which is there in the above link (Got it from here.... http://stackoverflow.com/questions/2236383/how-to-get-source-of-postback)

If the control name is your button then do not do what needs to be done upon postback.

HTH