Quit method question (Real Studio network user group Mailinglist archive)
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| [OT] How to compile Carbon Shared Library w/ProjectBuilder? - Hadley, Joshua | |||
| Quit method question - Terry Ford | |||
| Re: Quit method question - Thomas Reed | |||
| Re: Quit method question - Thomas Reed | |||
| Quit method question |
| Date: 11.12.02 23:37 (Wed, 11 Dec 2002 14:37:36 -0800) |
| From: Terry Ford |
|
Previously I submitted a question about the Restore operation in
4.5.2. My error was not checking for f.exists in a GetFolderItem that created a non-existent folderitem and tested for it's nil condition. Once I understood that it wouldn't show nil, I changed the code to check for f.exists (instead of f=nil )in an If...Then test and then give a MsgBox announcement and then quit the application. It worked perfectly when I entered the code in the open event of the modal window that I used to open files in the IDE debugger but it showed a watch cursor. When I built the application and tested it, however, the message came up with a normal cursor and after the quit command, I got the message that an ERROR:2 occurred in my built application. It didn't raise an exception error in the IDE debugger so I changed the code to self.close instead of quit. Now it showed as a nil object exception error in the debugger. I solved this problem by moving the test to the open event of the app class and that stopped the problem in both the IDE debugger and the built application. I have read in some of the NUG responses from RB that MsgBox has some quirky problems and should only be used for debugging purposes and NOT in a built application. Could this be the case here as all other cases of forcing a quit in all of my other windows (via a button coded for this purpose) works in both the debugger and the built application. My question is why when I checked for a folderitem=nil condition it passed the test but when I checked for a f.exists condition, it reported a nilobject error? |
| Re: Quit method question |
| Date: 12.12.02 16:29 (Thu, 12 Dec 2002 09:29:32 -0600) |
| From: Thomas Reed |
|
>I solved this problem by moving the test to the open event of the
>app class and that stopped the problem in both the IDE debugger and >the built application. That's odd, what you've done is usually a *cause* of problems. Quitting from an app's Open event (or closing from a window's Open event) can cause trouble, and is not really advisable. >I have read in some of the NUG responses from RB that MsgBox has >some quirky problems and should only be used for debugging purposes >and NOT in a built application. Yes, MsgBox is not meant for polished apps. You should design your own error message window. What I do is display a custom window using Show (*NOT* ShowModal). If there's an error that requires quitting in the app's Open event, this allows the app to go ahead and finish the startup process while the message is being displayed. When the user closes the error window, that window calls "Quit". This can be done easily by giving your error window a "quitOnClose as boolean" property and a method like the following: Sub ShowError(msg as string, fatal as boolean) StaticText1.text = msg quitOnClose = fatal Show End Sub Then, in the window's Close event, put: if quitOnClose then Quit end if >My question is why when I checked for a folderitem=nil condition it >passed the test but when I checked for a f.exists condition, it >reported a nilobject error? Can't say without seeing some code, but I'd say you're confused as to what's causing the NilObjectException, or the FolderItem being checked for nil isn't the same as the one being checked with the .Exists property. |
| Re: Quit method question |
| Date: 12.12.02 17:57 (Thu, 12 Dec 2002 10:57:31 -0600) |
| From: Thomas Reed |
|
>I solved this problem by moving the test to the open event of the
>app class and that stopped the problem in both the IDE debugger and >the built application. That's odd, what you've done is usually a *cause* of problems. Quitting from an app's Open event (or closing from a window's Open event) can cause trouble, and is not really advisable. >I have read in some of the NUG responses from RB that MsgBox has >some quirky problems and should only be used for debugging purposes >and NOT in a built application. Yes, MsgBox is not meant for polished apps. You should design your own error message window. What I do is display a custom window using Show (*NOT* ShowModal). If there's an error that requires quitting in the app's Open event, this allows the app to go ahead and finish the startup process while the message is being displayed. When the user closes the error window, that window calls "Quit". This can be done easily by giving your error window a "quitOnClose as boolean" property and a method like the following: Sub ShowError(msg as string, fatal as boolean) StaticText1.text = msg quitOnClose = fatal Show End Sub Then, in the window's Close event, put: if quitOnClose then Quit end if >My question is why when I checked for a folderitem=nil condition it >passed the test but when I checked for a f.exists condition, it >reported a nilobject error? Can't say without seeing some code, but I'd say you're confused as to what's causing the NilObjectException, or the FolderItem being checked for nil isn't the same as the one being checked with the .Exists property. (Sorry if this is a repost, Earthlink was having e-mail trouble earlier and I don't think these came through...) |