disappearing messagebox
i have this application with a central Controller object that is launched first (before any form, as it should be by default). If anything fails during initialisation an exception is raised, caught and a messagebox is shown. This latter disappears most of the times without having pressed anything. It certainly is shown because i see it pop up but it disappears again very quickly.
Since this is happening before any form is shown, i figured it may have to do something with the fact that i didn't have a messageloop at that moment yet and that the application simply shut down because of the lack of a messageloop, but it appears to be nothing to do with that because, when i changed my code so that i have a loop from the very start, the messagebox still disappeared very fast while my messageloop (and thus application) remains active.
Here's the code. I advise to scroll down to the Main() and then look at the OnApplicationIdle() handler. I use the Application.Idle event to launch everything, i disable the eventhandler after its first call because it only has to run once. I had to do this because i didn't want any form to be the central object, so i had to use Application.Run() instead of Application.Run(myForm).
I hope someone can give me some clues why the message decides to not wanting to be around anymore, because i really don't get this.
Private FctrlApplication As ClsCtrlApplication
Private FbInitialized As Boolean = False
Sub OnApplicationIdle(ByVal sender As Object, ByVal e As EventArgs)
RemoveHandler Application.Idle, AddressOf OnApplicationIdle ' make sure all this is done only once
FctrlApplication = New ClsCtrlApplication(GetType
Try
FctrlApplication.Initializ
FbInitialized = True
FctrlApplication.Execute()
Catch Ex As Exception
MessageBox.Show("A fatal error occurred: " & ClsChars.EOLDbl & Ex.Message, "Fatal error", MessageBoxButtons.OK, MessageBoxIcon.Error) ' this should wait for interaction, but it pops away quite fast
Application.Exit() ' when you drop this line, the application keeps on running after messagebox disappears
End Try
End Sub
Sub OnApplicationExit(ByVal sender As Object, ByVal e As EventArgs)
If FbInitialized Then FctrlApplication.Deinitial
If ClsCtrlApplication.IsInsta
FctrlApplication.Dispose()
End If
End Sub
'This method is the entrypoint of the application.
Sub Main()
'Idle event is exploited to start the application controller
AddHandler Application.Idle, AddressOf OnApplicationIdle
AddHandler Application.ApplicationExi
Try
'start main messageloop
Application.Run()
Finally
RemoveHandler Application.ApplicationExi
End Try
End Sub
Since this is happening before any form is shown, i figured it may have to do something with the fact that i didn't have a messageloop at that moment yet and that the application simply shut down because of the lack of a messageloop, but it appears to be nothing to do with that because, when i changed my code so that i have a loop from the very start, the messagebox still disappeared very fast while my messageloop (and thus application) remains active.
Here's the code. I advise to scroll down to the Main() and then look at the OnApplicationIdle() handler. I use the Application.Idle event to launch everything, i disable the eventhandler after its first call because it only has to run once. I had to do this because i didn't want any form to be the central object, so i had to use Application.Run() instead of Application.Run(myForm).
I hope someone can give me some clues why the message decides to not wanting to be around anymore, because i really don't get this.
Private FctrlApplication As ClsCtrlApplication
Private FbInitialized As Boolean = False
Sub OnApplicationIdle(ByVal sender As Object, ByVal e As EventArgs)
RemoveHandler Application.Idle, AddressOf OnApplicationIdle ' make sure all this is done only once
FctrlApplication = New ClsCtrlApplication(GetType
Try
FctrlApplication.Initializ
FbInitialized = True
FctrlApplication.Execute()
Catch Ex As Exception
MessageBox.Show("A fatal error occurred: " & ClsChars.EOLDbl & Ex.Message, "Fatal error", MessageBoxButtons.OK, MessageBoxIcon.Error) ' this should wait for interaction, but it pops away quite fast
Application.Exit() ' when you drop this line, the application keeps on running after messagebox disappears
End Try
End Sub
Sub OnApplicationExit(ByVal sender As Object, ByVal e As EventArgs)
If FbInitialized Then FctrlApplication.Deinitial
If ClsCtrlApplication.IsInsta
FctrlApplication.Dispose()
End If
End Sub
'This method is the entrypoint of the application.
Sub Main()
'Idle event is exploited to start the application controller
AddHandler Application.Idle, AddressOf OnApplicationIdle
AddHandler Application.ApplicationExi
Try
'start main messageloop
Application.Run()
Finally
RemoveHandler Application.ApplicationExi
End Try
End Sub
ASKER
yes, i do that too. i just removed that code for simplicity.
ASKER
I'm very curious now why that messagebox doesn't wait, i never wished more to be able to debug inside the framework as you can in Delphi.
Maybe i should make my own messagebox to find out what's going on.
In the meantime, thanks for replying Bob.
Thomas
Maybe i should make my own messagebox to find out what's going on.
In the meantime, thanks for replying Bob.
Thomas
I believe that Application.Exit is rather abrupt and overrides a lot of things.
How would you handle this in Delphi?
Bob
How would you handle this in Delphi?
Bob
ASKER
Calling Application.Exit may not be advisable at a higher level (in forms etc) but not here since nothing is left except for the win-messageloop and that is exactly what Application.Exit() terminates imho.
But the exit() can't have anything to do with the abrupt disappearance of the messagebox. For all i care, i even may add code to nuke the whole computer. This code may not be executed until the user clicks the messagebox away. So, the real and only problem is that the messagebox should idle the mainthread waiting for user input which it doesn't in this case, and that isn't right.
And for your question:
In Delphi, you simply can debug inside the "framework" until you reach API level and this way at least have a much bigger chance to find the reason why the messagebox doesn't wait ( i don't know how it works in delphi 8, never used delphi again since i changed work and switched to VS.NET).
I guess nobody can help me any further on this thread? Maybe another approach:
I wonder, how do other people implement MVC? Don't you need a central controller that starts other controllers with forms, datamodules, ... ? How do yóu start the controller first, and not that darn main-form?
But the exit() can't have anything to do with the abrupt disappearance of the messagebox. For all i care, i even may add code to nuke the whole computer. This code may not be executed until the user clicks the messagebox away. So, the real and only problem is that the messagebox should idle the mainthread waiting for user input which it doesn't in this case, and that isn't right.
And for your question:
In Delphi, you simply can debug inside the "framework" until you reach API level and this way at least have a much bigger chance to find the reason why the messagebox doesn't wait ( i don't know how it works in delphi 8, never used delphi again since i changed work and switched to VS.NET).
I guess nobody can help me any further on this thread? Maybe another approach:
I wonder, how do other people implement MVC? Don't you need a central controller that starts other controllers with forms, datamodules, ... ? How do yóu start the controller first, and not that darn main-form?
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Bob