Excel Vba Function Error Handling
Contents |
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 vba error handling best practices this site About Us Learn more about Stack Overflow the company Business Learn
Vba Error Numbers
more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question
Vba On Error Goto
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
Vba Error Handling Display Message
VBA Excel Error Handling - especially in functions - Professional Excel Development Style up vote 5 down vote favorite 4 I got the book "Professional Excel Development" by Rob Bovey and it is opening up my eyes. I am refitting my code with error handling. However, there is a lot I don't understand. I especially need to know how to correctly use it in vba on error exit sub functions. I use Bovey's rethrow version of the error handler (at bottom). When I started, I was using the basic boolean (non-rethrow) method and turned my subroutines into boolean functions. (P.S. I am switching back to the boolean method based on the answer.) I need guidance on how to fit functions into this scheme. I want them to return their real values (a string or double, e.g., or -1 if they fail in some cases) so I can nest them in other functions and not just return an error handling boolean. This is what a typical subroutine call to bDrawCellBorders(myWS) would look like within an entry point. Sub calls seem to be working well. (I.e. it is a subroutine that was turned into a function only so it can return a boolean to the error handling scheme.) Sub UpdateMe() ' Entry Point Const sSOURCE As String = "UpdateMe()" On Error GoTo ErrorHandler Set myWS = ActiveCell.Worksheet Set myRange = ActiveCell myWS.Unprotect ' lots of code If Not bDrawCellBorders(myWS) Then ERR.Raise glHANDLED_ERROR ' Call subroutine ' lots of code ErrorExit: On Error Resume Next Application.EnableEvents = True myWS.Protect AllowFormattingColumns:=True
soon) Ruby (coming soon) Getting Started Code Samples Resources Patterns and Practices App Registration Tool Events Podcasts Training API Sandbox Videos Documentation Office Add-ins Office Add-in Availability Office Add-ins Changelog Microsoft Graph API vba error handling in loop Office 365 Connectors Office 365 REST APIs SharePoint Add-ins Office UI Fabric Submit to vba try catch the Office Store All Documentation https://www.yammer.com/ http://feeds.feedburner.com/office/fmNx How do I... Miscellaneous Maintenance Maintenance Handle Run-Time Errors in VBA Handle Run-Time on error goto line Errors in VBA Handle Run-Time Errors in VBA Compact and Repair a Database Recover Tables Deleted from a Database Handle Run-Time Errors in VBA TOC Collapse the table of content Expand the table http://stackoverflow.com/questions/19042604/vba-excel-error-handling-especially-in-functions-professional-excel-developm of content This documentation is archived and is not being maintained. This documentation is archived and is not being maintained. Handle Run-Time Errors in VBA Office 2013 and later Other Versions Office 2010 Contribute to this content Use GitHub to suggest and submit changes. See our guidelines for contributing to VBA documentation. Errors and Error Handling When you are programming an application, you need to consider what happens https://msdn.microsoft.com/en-us/library/office/ff193267.aspx when an error occurs. An error can occur in your application for one of two of reasons. First, some condition at the time the application is running makes otherwise valid code fail. For example, if your code attempts to open a table that the user has deleted, an error occurs. Second, your code may contain improper logic that prevents it from doing what you intended. For example, an error occurs if your code attempts to divide a value by zero. If you have not implemented error handling, Visual Basic halts execution and displays an error message when an error occurs in your code. The user of your application is likely to be confused and frustrated when this happens. You can forestall many problems by including thorough error-handling routines in your code to handle any error that may occur. When adding error handling to a procedure, you should consider how the procedure will route execution when an error occurs. The first step in routing execution to an error handler is to enable an error handler by including some form of the On Error statement within the procedure. The On Error statement directs execution in event of an error. If there i
the wrong time. The application may crash. A calculation may produce unexpected results, etc. You can predict some of these effects and take appropriate actions. Some other problems are not http://www.functionx.com/vbaexcel/Lesson26.htm under your control. Fortunately, both Microsoft Excel and the VBA language provide various tools or means of dealing with errors. Practical Learning:Introducing Error Handling Open the Georgetown Dry Cleaning Services1 spreadsheet and click the Employees tab Click the Payroll tab Click the TimeSheet tab To save the workbook and prepare it for code, press F12 Specify the folder as (My) Documents In the Save As Type combo box, select error handling Excel Macro-Enabled Workbook Click Save Introduction to Handling Errors To deal with errors in your code, the Visual Basic language provides various techniques. One way you can do this is to prepare your code for errors. When an error occurs, you would present a message to the user to make him/her aware of the issue (the error). To prepare a message, you create a section of code in the procedure vba error handling where the error would occur. To start that section, you create a label. Here is an example: Private Sub cmdCalculate_Click() ThereWasBadCalculation: End Sub After (under) the label, you can specify your message. Most of the time, you formulate the message using a message box. Here is an example: Private Sub cmdCalculate_Click() ThereWasBadCalculation: MsgBox "There was a problem when performing the calculation" End Sub If you simply create a label and its message like this, its section would always execute: Private Sub cmdCalculate_Click() Dim HourlySalary As Double, WeeklyTime As Double Dim WeeklySalary As Double ' One of these two lines could produce an error, such as ' if the user types an invalid number HourlySalary = CDbl(txtHourlySalary) WeeklyTime = CDbl(txtWeeklyTime) ' If there was an error, the flow would jump to the label WeeklySalary = HourlySalary * WeeklyTime txtWeeklySalary = FormatNumber(WeeklySalary) ThereWasBadCalculation: MsgBox "There was a problem when performing the calculation" End Sub To avoid this, you should find a way to interrupt the flow of the program before the label section. One way you can do this is to add a line marked Exit Sub before the label. This would be done as follows: Private Sub cmdCalculate_Click() Dim HourlySalary As Double, WeeklyTime As Double Dim WeeklySalary As Double