Do set all object variables to nothing before ending the application.When the End statement is executed in the OLE client application, the OLEserver is shut down and the Terminate events

Don’t display errors from the OLE server. Instead, raise an error tothe client application. Use error numbers greater than vbObjectError +512 and less than vbObjectError + 5535. Values between vbObjectError

Often when using Transact-SQL, I want to capture comments from a user in a text box and send them tothe database. However, if the user types an apostrophe in the

I design VB applications for approximately 300 employees in a networked environment. It’s difficult to keepthose PCs up to date with the most current version of an app, so I

Use this algorithm to swap two integer variables: a = a Xor b b = a Xor b a = a Xor b

Place this code in the declaration section of a module: Public Sub Win95Shrivel(xForm As Form) ‘ Sets the form’s window status to ‘ minimized xForm.WindowState = 1End Sub Call it

When an image list is referenced by another object such as a toolbar, you can only add images to the imagelist. VB doesn’t allow deletes or changes to the size

I was developing a CGI application that read a database and pieced together the fields into a string forrepresentation as an HTML form. The surprise came when I found how

Code portability is extremely important, especially now that VBA is available in so many products. Someproblems might occur if you want to use VB4 or VB5 code in Access 8

Document the interface for your OLE server by using the Options buttonin the Object Browser. To provide more full-featured documentation, usea help file. Use the Object Browser to tie the

Pass as much data to and from the OLE server as possible in each call.Data transfer is fast, but calling is slow, especially with out-of-processservers. For example, you could pass

Don’t provide a method that terminates your server. Let the server automaticallyterminate when no references to the server exist. If you provide an Exitmenu option in an OLE server that

Test an in-process OLE server DLL by building it first as an out-of-processserver. This makes it possible to debug and test. Also, the stability ofthe entire application will be affected

The well-known Horner schema lets you calculate polynomial expressions efficiently. To calculate: A*x^N + B*x^(N-1) + . + Y*x + Z ( ^ means power ), simply write this expression

You can easily make a group of controls visible or invisible. At design time, select all controls you want tomake visible or invisible during the execution. Press F4, and assign

I often want to get to the General code section of a form quickly, either to hack module-level variables or tograb the procedure pull-down to find that function whose name

Do you sometimes need to format rounded numbers to a specific number of digits? You can accomplish thisin one step: n = 12.345Format(n, “0.00”)’returns “12.350”Format(n, “0.”)’returns “12.00”Format(0.55, “#.0”) ‘returns “.60”

If you set a form’s ControlBox property to False, the Minimize and Maximize buttons also become invisible.Suppose you want to provide functionality to the user to maximize and minimize the

Copy (Ctrl+C) and Paste (Crtl+V) functions are already includedin a text-box control, but what if you want to avoid these functions?You might suppose that you can handle Ctrl key combinations

Often, to create status-bar help, you place code in the mouse-moveevent procedures of controls to place text describing the controlon the status bar. Every time you update the text property,

If you need to analyze the performance of a Jet 3.0 query by thequery execution plan, you may do so by adding this registry keyand running regedit: \HKEY_LOCAL_MACHINESOFTWARE\_ MicrosoftJet3.0EnginesDebug For

In the “Determine the Class of YourObject with the TypeOfStatement” tip, the Desk and House objects have many propertiesin common. Instead of duplicating code by having a separate Printmethod for

vGive your ListView control in report view the sort functionalityof the Win95 Explorer. This code will allow you to sort by anycolumn. If your list is already sorted by the

Be aware that when using the Path property of the Applicationobject (App.Path), if your EXE is run from the root directoryof a drive, App.Path will return the drive letter and

Sometimes it is desirable to prevent a user from moving a form.A little known feature of Windows is that for any form, functionalitythat doesn’t appear in the control menu (ControlBox

Sometimes a runtime error only manifests itself after an EXE ismade and not in debug mode. This can be hard to track down, evenwith message-box statements. Use the code profiler

I like to use the Constant.txt file Microsoft has been kind enoughto provide. For a new project, copy Constant.txt to a new filesuch as MyConst.txt. Place MyConst.txt in the same

This code will prevent a beep when you hit [ENTER] or [TAB] ina text box whose maximum character limit has been reached: Sub Form_KeyPress (keyascii As Integer)’Eliminate beep if {ENTER}

In VB4 the TypeOf statement works with any valid object type,not just forms and controls. This allows you to pass objects ofdifferent classes to the same procedure for a class-specific