Re: Splash Screen - My Nemesis

> handling exceptions in the Load ...  don't do it, it's unpredictable

Same experience here - unpredictable...  quite frustrating the first
time you run into it :)


-----Original Message-----
From: Discussion forum for developers using Windows Forms to build apps
and controls [mailto:[email protected]] On Behalf Of
Greg Robinson
Sent: 26 July 2007 01:58 PM
To: [email protected]
Subject: Re: [DOTNET-WINFORMS] Splash Screen - My Nemesis

I am not going to argue with you.  Contact MS and listen to their
feedback
on handling exceptions in the Load.

I may have said it the wrong way, but we saw all kinds of problems with
handling exceptions in the Load event handler when we first started
working
with .NET 5+ years ago.  We ended up calling MS and were pretty much
told
don't do it, it's unpredictable.


-----Original Message-----
From: Discussion forum for developers using Windows Forms to build apps
and controls [mailto:[email protected]]On Behalf Of
Brady Kelly
Sent: Thursday, July 26, 2007 7:54 AM
To: [email protected]
Subject: Re: [DOTNET-WINFORMS] Splash Screen - My Nemesis


Now I've heard it all.  Just what do you think this code will do:

        private void Form1_Load(object sender, EventArgs e)
        {
            try
            {
                MakeDoodoo();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        private void MakeDoodoo()
        {
            throw new Exception("Just ignore me!");
        }



> -----Original Message-----
> From: Discussion forum for developers using Windows Forms to build
apps
> and controls [mailto:[email protected]] On Behalf Of
> Greg Robinson
> Sent: 26 July 2007 13:29 PM
> To: [email protected]
> Subject: Re: [DOTNET-WINFORMS] Splash Screen - My Nemesis
>
> Exception Handling is ignored in the Load.
>
>
>
> -----Original Message-----
> From: Discussion forum for developers using Windows Forms to build
apps
> and controls [mailto:[email protected]]On Behalf Of
> Brady Kelly
> Sent: Wednesday, July 25, 2007 4:49 PM
> To: [email protected]
> Subject: Re: [DOTNET-WINFORMS] Splash Screen - My Nemesis
>
>
> Thank you so much Andrew!  This is the first code I've found tonight
> that
> worked a anything like it should, and I all wanted to do was 'whip out
a
> splash screen quickly' for a small side project.  Whew!
>
> However, I have one problem: I'm using the splash screen to show while
I
> query a database during the form load event handler.  If I get an
error
> in
> this method, the splash screen simply hangs.  I tried adding a static
> Abort() method to the Splash class, which works but I still get
> different
> behaviours in the IDE and compiled.
>
> First, in the IDE, I get my desired MessageBox, but it the compiled
app
> there is none.  Here is my use of your code:
>
>         private void SearchGrid_Load(object sender, EventArgs e)
>         {
>             try
>             {
>                 SplashManager.Show(this, typeof(SplashScreen), new
> TimeSpan(0, 0, 0, 0, 500));
>                 InitControls();
>             }
>             catch (Exception ex)
>             {
>                 LogException(ex);
>                 SplashManager.Abort();
>                 MessageBox.Show(this, ex.Message, "Startup Error",
> MessageBoxButtons.OK, MessageBoxIcon.Warning);
>                 Close();
>             }
>             finally
>             {
>                 Cursor = Cursors.Default;
>             }
>         }
>
>
>
> > -----Original Message-----
> > From: Discussion forum for developers using Windows Forms to build
> apps
> > and controls [mailto:[email protected]] On Behalf
Of
> > Eames, Andrew
> > Sent: 25 July 2007 21:52 PM
> > To: [email protected]
> > Subject: Re: [DOTNET-WINFORMS] Splash Screen - My Nemesis
> >
> > I too found a lot of incorrect ways to implement a splash screen.
Many
> > of the public domain implementations I looked at had subtle bugs
> and/or
> > race conditions in them too. I ended up writing the following code
> which
> > you are welcome to borrow
> >   Andrew
> >
----------------------------------------------------------------------
> --
> > ---------------------------------------------------------------
> >   /// <summary>
> >   /// Class that manages a splash screen
> >   /// </summary>
> >   public class SplashScreen
> >   {
> >     SplashScreen(Form parentForm, Type splashType, TimeSpan
timeSpan)
> >     {
> >       parentForm_ = parentForm;
> >       splashType_ = splashType;
> >       timeSpan_ = timeSpan;
> >       culture_ = CultureInfo.CurrentCulture;
> >       parentForm.Shown += new EventHandler(OnParentShown);
> >       Thread t = new Thread(new ThreadStart(SplashThread));
> >       t.Start();
> >     }
> >
> >     // This is the entry point for the thread that the splash screen
> > runs on
> >     void SplashThread()
> >     {
> >       Thread.CurrentThread.CurrentCulture =
> > Thread.CurrentThread.CurrentUICulture = culture_;
> >       splashForm_ = (Form)Activator.CreateInstance(splashType_);
> >       splashForm_.TopMost = true;
> >       splashForm_.ShowInTaskbar = false;
> >       splashForm_.FormBorderStyle = FormBorderStyle.FixedToolWindow;
> //
> > prevents appearing in alt-TAB
> >       splashForm_.StartPosition = FormStartPosition.CenterScreen;
> >       splashForm_.HandleCreated += delegate {
> > splashHandleCreated_.Set(); };
> >       using (System.Windows.Forms.Timer timer = new
> > System.Windows.Forms.Timer())
> >       {
> >         timer.Interval = (int)timeSpan_.TotalMilliseconds;
> >         timer.Tick += delegate { timerExpired_ = true;
MaybeClose();
> };
> >         timer.Start();
> >         Application.Run(splashForm_);
> >       }
> >     }
> >
> >     void MaybeClose()
> >     {
> >       // We don't close the splash screen until both the timer has
> > expired and the main form has shown itself
> >       if (timerExpired_ && shown_)
> >       {
> >         // Note: We activate the parent form *before* closing the
> splash
> > form, otherwise the windows paint
> >         // in a distracting way
> >         try
> >         {
> >           parentForm_.Invoke(new foo(delegate {
> parentForm_.Activate();
> > }));
> >         }
> >         catch (InvalidOperationException)
> >         {
> >           // In case the parent has closed already!!
> >         }
> >         splashForm_.Close();
> >         splashHandleCreated_.Close();
> >       }
> >     }
> >     /// <summary>
> >     /// Executed on the splash form thread
> >     /// </summary>
> >     void OnParentShown()
> >     {
> >       shown_ = true;
> >       MaybeClose();
> >     }
> >
> >     /// <summary>
> >     /// Raised on the thread of the main form
> >     /// </summary>
> >     /// <param name="sender"></param>
> >     /// <param name="e"></param>
> >     void OnParentShown(object sender, EventArgs e)
> >     {
> >       parentForm_.Shown -= new EventHandler(OnParentShown);
> >       // If the parent shows itself really quickly, its possible
that
> > the splash screen has
> >       // not yet created its window, which is why we use this event
> >       splashHandleCreated_.WaitOne();
> >       // Note we need to use BeginInvoke to avoid a potential
deadlock
> > since
> >       // the splash form may Invoke an activate right back at us
> >       splashForm_.BeginInvoke(new foo(OnParentShown));
> >     }
> >
> >     /// <summary>
> >     ///
> >     /// </summary>
> >     /// <param name="parentForm"></param>
> >     /// <param name="splashType"></param>
> >     /// <param name="time"></param>
> >     public static void Show(Form parentForm, Type splashType,
TimeSpan
> > time)
> >     {
> >       new SplashScreen(parentForm, splashType, time);
> >     }
> >
> >     TimeSpan timeSpan_;
> >     Type splashType_;
> >     Form parentForm_;
> >     Form splashForm_;
> >     CultureInfo culture_;
> >     ManualResetEvent splashHandleCreated_ = new
> ManualResetEvent(false);
> >     bool shown_;
> >     bool timerExpired_;
> >   }
> >
> >   delegate void foo();
> >
> > -----Original Message-----
> > From: Discussion forum for developers using Windows Forms to build
> apps
> > and controls [mailto:[email protected]] On Behalf
Of
> > Brady Kelly
> > Sent: Wednesday, July 25, 2007 3:39 PM
> > To: [email protected]
> > Subject: [DOTNET-WINFORMS] Splash Screen - My Nemesis
> >
> > Yes, I've just spent hours trying various examples that don't work,
> and
> > I've
> > just realised why people Callout actually _sell_ splash screen
> products.
> > My
> > biggest grip so far is that in the compiled app, not in the IDE, my
> main
> > window, from which I display my splash screen, always appears in the
> > background.
> >
> >
> >
> > My code is outrageously simple, with no status updates or anything:
> >
> >
> >
> >         public SearchGridForm()
> >
> >         {
> >
> >             InitializeComponent();
> >
> >             splashScreen = new SplashScreen();
> >
> >             splashThread = new Thread(new ThreadStart(ShowSplash));
> >
> >             splashThread.Start();
> >
> >         }
> >
> >
> >
> >         private void ShowSplash()
> >
> >         {
> >
> >             splashScreen.ShowDialog();
> >
> >         }
> >
> >
> >
> >         private void SearchGrid_Load(object sender, EventArgs e)
> >
> >         {
> >
> >             try
> >
> >             {
> >
> >                 Cursor = Cursors.WaitCursor;
> >
> >                 InitControls();
> >
> >             }
> >
> >             finally
> >
> >             {
> >
> >                 Cursor = Cursors.Default;
> >
> >                 splashThread.Abort();
> >
> >             }
> >
> >         }
> >
> >
> > --
> > BEGIN-ANTISPAM-VOTING-LINKS
> > ------------------------------------------------------
> >
> > NOTE: This message was trained as non-spam.  If this is wrong,
> > please correct the training as soon as possible.
> >
> > Teach CanIt if this mail (ID 9056513) is spam:
> > Spam:
> > http://mail-gw.cognex.com/canit/b.php?c=s&i=9056513&m=08b08c6e418b
> > Not spam:
> > http://mail-gw.cognex.com/canit/b.php?c=n&i=9056513&m=08b08c6e418b
> > Forget vote:
> > http://mail-gw.cognex.com/canit/b.php?c=f&i=9056513&m=08b08c6e418b
> > ------------------------------------------------------
> > END-ANTISPAM-VOTING-LINKS