VBA + Excel + Try Catch

Private Sub Workbook_Open()    on error goto Oops    version = "1.0"    Set objHTTP = CreateObject("WinHttp.WinHttpRequest.5.1")    URL = "<WEB SERVICE>"    objHTTP.Open "POST", URL, False    objHTTP.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"    objHTTP.setRequestHeader "Content-type", "application/x-www-form-urlencoded"    objHTTP.send ("version=" + version)    exit subOops:    'handle error hereEnd Sub   

If you wanted to, for example, change the URL because of the error, you can do this

Private Sub Workbook_Open()    on error goto Oops    version = "1.0"    Set objHTTP = CreateObject("WinHttp.WinHttpRequest.5.1")    URL = "<WEB SERVICE>"Send:    objHTTP.Open "POST", URL, False    objHTTP.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"    objHTTP.setRequestHeader "Content-type", "application/x-www-form-urlencoded"    objHTTP.send ("version=" + version)    exit subOops:    'handle error here    URL="new URL"    resume Send 'risk of endless loop if the new URL is also badEnd Sub   

Also, if your feeling really try/catchy, you can emulate that like this.

Private Sub Workbook_Open()    version = "1.0"    Set objHTTP = CreateObject("WinHttp.WinHttpRequest.5.1")    URL = "<WEB SERVICE>"    on error resume next 'be very careful with this, it ignores all errors    objHTTP.Open "POST", URL, False    objHTTP.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"    objHTTP.setRequestHeader "Content-type", "application/x-www-form-urlencoded"    objHTTP.send ("version=" + version)   if err <> 0 then      'not 0 means it errored, handle it here      err.clear 'keep in mind this doesn't reset the error handler, any code after this will still ignore errors   end ifEnd Sub  

So extending this to be really hard core...

Private Sub Workbook_Open()    version = "1.0"    on error resume next    Set objHTTP = CreateObject("WinHttp.WinHttpRequest.5.1")    if err <> 0 then        'unable to create object, give up        err.clear        exit sub    end if    URL = "<WEB SERVICE>"    objHTTP.Open "POST", URL, False    if err <> 0 then        'unable to open request, give up        err.clear        exit sub    end if    objHTTP.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"    objHTTP.setRequestHeader "Content-type", "application/x-www-form-urlencoded"    objHTTP.send ("version=" + version)   if err <> 0 then      'unable to send request, give up      err.clear      exit sub   end ifEnd Sub  

Also worth noting that any errors that happen in an on error goto style will not be handled, so if you did this

private sub MakeError()   dim iTemp as integer   on error goto Oops   iTemp = 5 / 0 'divide by 0 error   exit subOops:   itemp = 4 / 0 'unhandled exception, divide by 0 errorend sub

Will cause an unhandled exception, however

private sub MakeError()   dim iTemp as integer   on error resume next   iTemp = 5 / 0 'divide by 0 error   if err <> 0 then       err.clear       iTemp = 4 / 0 'divide by 0 error, but still ignored       if err <> 0 then           'another error       end if   end ifend sub

Will not cause any exceptions, since VBA ignored them all.

Something like this:

Try    ...Catch (Exception e)    ...End Try

Might look like this in VBA:

' The "Try" partOn Error Resume Next...On Error GoTo 0' The "Catch" partIf Err.Number <> 0 Then...End If

However, this form may not be following best practices.