h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I hope this isn't too simple for you all. In Visual Basic how can you tell when an InputBox has been returned without anything being entred into it. I've had a go with IsNull and IsEmpty, but with no success.

Thanks.

Just guessing (I haven't used VB for about 8 years) but how about:

if myinput.value = "" then ...?

My understading of an Input Box, is a little one lines text box control.

Do you mean the File Input Save/Open Box that comes as a control?

There is two ways, set the cancel Error to true and use some error handling. or check for File = "", simple.

If you need some better code, I got a module so you don't have to include that silly control with your project.

-- DoctorMO --

Yes, I tried = "" and it didn't work.

This is what I have:

Dim Year
Year = InputBox ("Enter the Year")
x
If Year < 1700 Then GoTo Line3
If Year > 2299 Then GoTo Line2 Else GoTo Line1

I want something at x that says if Year = no value entred then go somewhere else.

What do you think?

You may want to convert Year to an Integer

Year = Int(InputBox("Enter the Year"))

If Year = 0 Then Goto NOTHING
If Year < 1700 Then GoTo Line3
If Year > 2299 Then GoTo Line2 Else GoTo Line1

Try that.

-- DoctorMO --

Again, working from memory, you could modify it to:

Dim Year as string*4
Year = InputBox ("Enter the Year")
x
If eval(Year) < 1700 Then GoTo Line3
If eval(Year) > 2299 Then GoTo Line2 Else GoTo Line1

and after that testing against "" should work. ,erm>

Tecnicaly that would work, but it's a messy way to deal with a number from a string input.

-- DoctorMO --

Well, I'm not entirely certain that INT of a null value will evaluate to 0....

I tried making the year an integer and it nearly worked. But, when nothing is typed, is is not seen as zero. Typing in 0 gives the desired result but not just leaving it blank.

At the moment when nothing is typed I think it is seen as > 2299. Infinity perhaps?

I think making the year a string may cause problems when a year is entered with 5 digits.

Don't worry, they're bound to make the calendar hexadecimal sometime in the next 8000 years or so...

Thanks for the help. I think I'll just wait for hexidecimalisation. It wasn't anything important. I was messing with an Excel Macro that I got off h2g2. It's to calculate the date of Easter. You can find it if you search for Easter up there. It's worth a look. I can't take credit for any of the clever stuff though.

Bye for now.

you could try seeing what the string is first.

So for example:

Dim theyear As String
theyear = InputBox("Enter the year")
If theyear = "" Then GoTo noyear
Dim a As Integer
a = theyear
MsgBox "a is " & a
Exit Sub
noyear:
MsgBox "No Year"

I've just tried it and that works.

Jonny