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VB structured data types

Started by KalvinB Dec 3, 2001 at 5:09 PM 2 replies 350+ views

Original Post

Dec 3, 2001 at 5:09 PM

I have a function that loads a file straight to a struct

  
in.open(file,ios::binary)
in.read((char*)&struct,sizeof(struct));
in.close();

what''s the equivilent source in VB? I basically need to know how to set up a struct in VB and load a file into it. Ben

ragonastick

Dec 3, 2001 at 10:26 PM

Unless I''m misinterpreting the question (quite likely

), then it works like this:


Type MyStruct
 Blah1 As Integer
 Blah2 As Long
 Blah3(5) As Byte
 Blah4 As String * 4
End Type

Function LoadStuff(Filename As String) As MyStruct
 Dim Filenum As Long

 Filenum = FreeFile
 Open Filename For Binary As Filenum

 Get Filenum, 1, LoadStuff

 Close Filenum
End Function

A few things you have to watch out for are the dynamic types (variable length strings and dynamic arrays), when written, VB puts in short headers describing their size, so unless you write those same headers with C++, then you can''t use those types.

Trying is the first step towards failure.

KalvinB

Author

KalvinB

Dec 3, 2001 at 11:13 PM

That sounds about right.

Thanks,

Ben

KalvinB

Author

KalvinB

Dec 5, 2001 at 1:00 PM

For some reason VB is saying I can't use Get to write to the struct. I can use Input to read to a variable but not Get.

-edit-
Figured it out. By default a type is public but it needs to be private.

Ben

Edited by - KalvinB on December 6, 2001 1:48:22 PM

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