Error Goto Vb6
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Database Guide User login Username: * Password: * Request new password Home › Tutorials Error handling in Visual Basic Level: Error handling is essential to all professional applications. Any vb6 on error goto 0 number of run-time errors can occur, and if your program does not
Vb6 Error Handling
trap them, the VB default action is to report the error and then terminate the program (often resulting in
Vb6 On Error Resume Next
the end user calling you and complaining, "Your program kicked me out!"). By placing error-handling code in your program, you can trap a run-time error, report it, and let the user
Vb6 On Error Not Working
continue. Sometimes the user will be able to correct the error and sometimes not, but simply allowing the program to crash is not acceptable. You should generally place error-handling code in any Sub or Function that accesses files or databases. Your code will typically interrogate the Number and Description properties of the built-in VB Err object in an error-handling routine set up vb6 on error goto example with the On Error statement. In this section, we will look at the following statements: On Error GoTo label On Error Resume Next Following is a brief tutorial in error-handling. To perform this tutorial, you should have a floppy disk handy. Also, in the VB IDE, make sure that the Break on Unhandled Errors option is set under Tools à Options à General. STEPS: 1. Start a new project. 2. Place four command buttons on the form. Name them and set their Captions as follows: Name Caption cmdCrash Crash cmdGoToLabel GoTo Label cmdGoTo0 GoTo 0 cmdResumeNext Resume Next Your form should look something like this: 3. Code the cmdCrash_Click event as follows: Private Sub cmdCrash_Click() Open "A:\JUNK.TXT" For Input As #1 MsgBox "File was opened successfully" Close #1 End Sub 4. Place your floppy disk in the A: drive. Run the program and click the Crash button. Assuming that you do not have a file called "JUNK.TXT" on your A: disk, the program will "bomb" with the code/message "53 – File Not Found". I
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company vb6 throw error Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs on error goto errorhandler Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, visual basic on error goto line just like you, helping each other. Join them; it only takes a minute: Sign up Confused about Error Handling in VB6 and the use of On Error GoTo up vote 3 down vote favorite 1 I'm needing http://www.vb6.us/tutorials/error-handling-visual-basic to troubleshoot some old VB6 code and I'm confused about the use of "On Error". In the sample below, if I surround the specific line of code I want to test with the On Error GoTo and the ErrHandler1, is that the ONLY line that's tested. Or will the divide by Zero be included if it's in the same Sub? On Error GoTo ErrHandler1 If Not Exists(BaseDirectory + "\ARCHIVE") Then _ MkDir BaseDirectory + http://stackoverflow.com/questions/9035664/confused-about-error-handling-in-vb6-and-the-use-of-on-error-goto "\ARCHIVE" ErrHandler1: Call MsgBox(Err.Number & vbCrLf & Err.Description, vbExclamation, App.Title) intValue1 = 12 intValue2 = 0 intValue3 = intValue1 / intValue Thanks. vb6 error-handling share|improve this question asked Jan 27 '12 at 15:25 JimDel 2,05453369 add a comment| 3 Answers 3 active oldest votes up vote 8 down vote accepted The divide by zero will be included and handled, and it will probably create a loop in your sample... The correct approach is like that On Error GoTo ErrHandler1 If Not Exists(BaseDirectory + "\ARCHIVE") Then _ MkDir BaseDirectory + "\ARCHIVE" On Error Goto 0 'this will un-hook you error handler intValue1 = 12 intValue2 = 0 intValue3 = intValue1 / intValue 'this will be an un-managed error Exit Sub 'this make sure that msgbox is shown only when the error happens ErrHandler1: Call MsgBox(Err.Number & vbCrLf & Err.Description, vbExclamation, App.Title) share|improve this answer answered Jan 27 '12 at 15:48 Max 4,14011426 Thanks for the explanation! –JimDel Jan 27 '12 at 16:47 +1. The documentation explains this pretty clearly... msdn.microsoft.com/en-us/library/aa266173(v=vs.60).aspx –MarkJ Jan 27 '12 at 16:53 3 Wrong - the division by zero is only handled if the MkDir operation does not thrown an error –Matt Wilko Jan 27 '12 at 16:58 @Matt: you are absolutely correct :) –Max Jan 27 '12 at 19:39
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack http://stackoverflow.com/questions/9983464/why-would-you-ever-use-on-error-goto-0 Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Why would you ever use “On Error Goto 0”? up vote 19 down vote favorite 5 Why would you ever use "On Error Goto 0" in a VB6 app? This statement turns the error handler off and would mean that any error would crash the on error app. Why would this ever be desirable? vb6 error-handling share|improve this question asked Apr 2 '12 at 20:37 CJ7 4,95832112219 4 Well, it's certainly a way of implementing fail-fast –Greg Hewgill Apr 2 '12 at 20:39 I don't have VB6 installed, but presumably any Goto statement to a non-existant label would crash the app. –Sam Axe Apr 2 '12 at 20:40 This sounds like a comment from somebody who either throws in On Error Resume Next at the head of each vb6 on error procedure and then has mysterious woes that can't be diagnosed, or one who puts in On Error GoTo MyHandler and there just pops up a MsgBox with the same error anyway. –Bob77 Apr 2 '12 at 21:14 2 Not true at all. It is commonly paired with On Error Resume Next and a test of Err.Number to do inline structured error handling. –Bob77 Apr 3 '12 at 0:52 1 @CraigJ: Remember that the error handling is for that procedure (and children) only. "Turning it off" is NOT global, and allows errors to be handled by the parent. –Deanna Apr 3 '12 at 15:28 | show 9 more comments 4 Answers 4 active oldest votes up vote 35 down vote In VB6, you can specify that you want errors to be handled by particular code later in the routine: Sub Bar() On Error Goto MyHandler ... ...some code that throws an error... ... Exit Sub MyHandler: ...some error handler code (maybe pops up a dialog) End Sub It may be the case, however, that the code that throws the error is localized, and you don't want that same handler for all of the rest of the code in the routine. In that case, you'd use "On Error Goto 0" as follows: Sub Bar() ... On Error Goto MyHandler ...some code that throws an error... On Error Goto 0 ... ... Exit Sub MyHandler: ...some error handler code (maybe pops up a dialog) End Sub Now you have effectively scoped the error handling to execute onl