byref fails with fixed length string

[bobr]

If you declare a string as:
Dim fred as string * 256
' Then call a function
sid(fred)

' where the function sid() is declared as:
function sid(byref data as string)
data = "a bit of text"
end function

the text string isn't passed back to the variable in the call. If, however, fred is declared as:
Dim fred as string

the text string is passed back correctly.

[Slowdown]

No need for Byref.
If you use a function do it like this,

Code: Select all

Dim fred as string * 256

Private Sub Form_OnOpen()
  fred = "this a bit of text"
  print sid(fred) 
End Sub

Function sid(data as String) As String
  Return data
End Function


This will be returned as expected.

[bobr]

Yes, I know that I can pass the value back by "return". My little example was just to show what goes wrong. If you are calling a function that returns more than one value, you need to use "byref". My point is that if you are passing a fixed length string, the "byref" value doesn't get passed back!

[Henning]

My guess is you have to live with one of two work-arounds.

1. Copy Fred to a temp string, and then back again.

2. Make Fred Public, and not pass it at all.

/Henning