Unicode and Visual Basic: A Case Study

1
Unicode and Visual Basic A Case Study

• Michael S. Kaplan
• Software Design Engineer
• Trigeminal Software, Inc.http//www.trigeminal.co
  m

http//www.i18nWithVB.com/
2
The purpose of Visual Basic

• Making Windows development easier
• Promote the Windows platform through ISVs who use
  it
• The "apple in Bill's eye"

3
International support in the early versions

• Very limited!
• Multiple versions of the product codebase
• Bugs found in one language version often not
  fixed elsewhere
• Certainly NO Unicode support

4
VB 4.0 - a time for choices
5
Keep VB in 16 bit, and take advantage of the
support for Win16 applications

• Easy for VB to do
• Useless for the Win32 platform itself
• No international support at all

6
Move VB to Win32 entirely, leveraging the
emerging NT platform's full support of Unicode
through its "W" APIs.

• Great international solution
• Poor solution for Windows 95

7
Move VB to Win32 but still with a code page model
rather than a Unicode one, using the "A" APIs.

• Easiest to do
• Less multilingual support

8
A hybrid technique ("A" APIs on Win9x, "W" APIs
on NT)

• Most complicated to do
• Best international support
• Good leveraging of the best features of each
  platform

9
What the VB team actually did

• Using COM
• Porting the original VB
• Working with the volume platform (Windows 95)

10
Where COM fits in

• Benfits to VB by using COM
• Benefits to COM by VB being a client

11
The birth of "UniMess"

• An attempt to keep the conversion from VB3 to VB4
  simple
• From simplicity comes confusion

12
The cousin of UniMessUsing LCIDs for code pages

• COM's biggest drawback
• Once again, simplicity causes problems

13
Beyond UniMess

• Intrinsic function woes
• Source file encoding compatibility
• Trouble with the Ruby forms package
• Difficulties with API calls
• Problems with file i/o

14
The verdict for VB4?
15
Changes in VB5

• Minor functionality enhancements
• No major changes for Unicode support
• Some work with the StrConv function

16
Changes in VB6

• More work with StrConv
• A lot of VB-specific code moved to COM
• A lot of other VB-specific functionality now
  using existing COM methods

17
And then came VB.NET

• System.Text
• System.Globalization
• System.Resources
• The unicode Visual Studio IDE

18
Lessons learned

• Was VB4 a good Unicode integration?
• Were VB5 and VB6 good integrations?
• What about VB.NET?

19
Summary of lessons learned

• Backwards compatibility is crucial
• Conversion between Unicode and other encodings is
  crucial
• New data types need new constructs
• Understand why you are supporting Unicode (the
  primary reasons for that support)
• Know what supplementary benefits you will gain
  from Unicode

20
Questions?
21

• Unicode and Visual BasicA Case Study