Clash Royale CLAN TAG

Conversion from string “” to type Long is not valid

How can I fix this error? I am updating this code from VB.06 to vb.net everything is working correctly except this line. And it is happening only when the order number is wrong

2 Answers
2

it depends on how you like to handle the error.
you can wrap the line with

if txtOrderQty.text <> "" then

end if


and let the code to continue.

or you can issue a warning message before processing further.

The string "" can not be converted to Long because it is not a number.

""

Long

You can use TryParse to convert the string to Long. If it can not be parsed then 0 is returned into the variable in the second argument (orderQty):

TryParse

Long

0

orderQty

Dim orderQty As Long
Long.TryParse("", orderQty)
lblToBeScanned1.Text = (orderQty - lngUPC1).ToString()


By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.