| Visual Basic 2.0, announced in early November, promises
to be a significant revision that adds more of everything:
controls, properties, keywords, events, debugging tools,
programming aids, and — perhaps most
important — performance. What follows is a look at some of
the significant new additions, based on preliminary
documentation, a beta version of the software, and
Microsoft sources. VB 2.0 will be available in both a Standard Edition and a Professional Edition. The Professional Edition replaces the Professional Toolkit 1.0 and the Control Development Kit, and several features from Toolkit 1.0 have been added to the new Standard Edition. Among these are the OLE client control and the grid control, a spreadsheet object that has been improved over the version in Toolkit 1.0. The toolbox in both editions has two new controls. The graphical control lets you create shapes, lines, and labels like earlier controls, but it uses fewer Windows resources so you can build bigger applications. The other new control is the image box. Like a picture box, it can display BMP and ICO graphics files, but unlike a picture box, it can resize the images as well. Also, graphics can be displayed in 256 instead of 16 colors. All control properties in VB 2.0 are now displayed in a movable, scrolling window instead of a static list box. Global and type definitions, formerly allowed only in the GLOBAL.BAS file, can now be included in any code module (but not form modules). If you begin your declarations section with the new Option Explicit statement, VB 2.0 requires all variables to be declared before use. Although this feature imposes somewhat more structure on the programmer, it makes the source code easier to understand and maintain, especially in projects involving workgroups. Several improvements make it possible to write larger applications. VB 2.0 allows four times as many procedures per application, twice as many variables per module, twice as many global variables, twice as many controls per form, unlimited string space (up to the limit of available memory), and arrays that break the 64-KB memory barrier (but only in Windows enhanced mode). You can put more than 255 controls on a form by grouping the controls in arrays, and you can also include arrays in user-defined variable types. All indications suggest that Visual Basic 2.0 will be a significant upgrade and a release worth watching closely. Tom R. Halfhill is BYTE's senior news editor in San Francisco. You can contact him on BIX as "thalfhill." Copyright 1994-1997 BYTE |