Selecting Theme in DropDownList

skijor · July 29th, 2009, 11:16 AM

First I really like your book. Excellent.

I had some strange behavior with selecting my theme. It was working, I could select between the themes. Then (I must have done something) it stopped working and would only show the grey theme. I double clicked the dropDownlist in design view expecting to go to SelectedIndexChanged event but instead it added another one called ..SelectedIndexChanged1. So I copied the code from SelectedIndexChanged into this new event and everything works. Do you know why this would happen? If I double click on a control it should take me to the control's event and not create a new one right?

Also, I'm using VS2008 professional edition with service pack1 on Vista ultimate and it crashes occasionally, esp. if I undock windows and then switch views. The above happened after the IDE crashed.

Code:

 protected void lstPreferredTheme_SelectedIndexChanged(object sender, EventArgs e)
    {
      // Retrieves the selected theme from a DropDownList and stores it in a cookie.
      HttpCookie preferredTheme = new HttpCookie("PreferredTheme");
      // set cookie to expire in three months. If user selects again then saves agian.
      preferredTheme.Expires = DateTime.Now.AddMonths(3);
      preferredTheme.Value = lstPreferredTheme.SelectedValue;
      Response.Cookies.Add(preferredTheme);
      // Redirect the user to the same page. This is necessary because otherwise the new theme won't
      // be applied immediatly since the theme needs to be set early in the page's life cycle. By
      // redirecting a new request is made which can successfully applyl the selected theme.
      Response.Redirect(Request.Url.ToString());
    }
    protected void lstPreferredTheme_SelectedIndexChanged1(object sender, EventArgs e)
    {
      // Retrieves the selected theme from a DropDownList and stores it in a cookie.
      HttpCookie preferredTheme = new HttpCookie("PreferredTheme");
      // set cookie to expire in three months. If user selects again then saves agian.
      preferredTheme.Expires = DateTime.Now.AddMonths(3);
      preferredTheme.Value = lstPreferredTheme.SelectedValue;
      Response.Cookies.Add(preferredTheme);
      // Redirect the user to the same page. This is necessary because otherwise the new theme won't
      // be applied immediatly since the theme needs to be set early in the page's life cycle. By
      // redirecting a new request is made which can successfully applyl the selected theme.
      Response.Redirect(Request.Url.ToString());
    }

skijor · July 29th, 2009, 11:40 AM

I think somehow the SelectedIndexChanged in the properties events window was cleared out. I cannot replicate it anyother way i.e. when I double click on the theme dropdown in design it brings me to my event. I deleted my SelectedIndexChanged1 and "rewired" to SlectedIndexChanged and everything is back to normal. It's strange that it would clear the event in the first place.

Imar · July 29th, 2009, 12:04 PM

Yeah, I've seen that a few times before as well. Here's how I can reproduce it:

1. Add a DDL in Design View

2. Double click the DLL to setup the handler and go to the Code Behind

3. Save all your changes

4. Go to the Markup and press Ctrl+Z once to undo your changes. This removes the handler from the DDL markup, but not from the code behind.

5. Save again.

6. Double click the handler again in Design View. VWD sees the existing handler, and thus creates a new one with a sequential number.

Cheers,

Imar

skijor · July 29th, 2009, 01:51 PM

You refreshed my memory. I was playing around in the markup and I did quite a few Ctrl z's. Good to know.

Thanks Imar.