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Running applications written in VB3 in the WIN95 OS is not always aclean conversion. This code would work fine in Windows for Workgroups 3.11,but would GPF in WIN95. SS3D2.VBX, which
When loading a form, reduce the “flicker” and “flash” of the GUI by using these Windows API functions: ‘Declarations Section#If Win32 Then Declare Function LockWindowUpdate _ Lib “user32” _ (ByVal
Optional parameters are a great new feature in VB4, but the ParamArraykeyword is an overlooked addition to function and subroutine declarations.The ParamArray keyword allows an unspecified number of Variantparameters to
To have a program programmatically close another program, use this code: ‘ Close an existing program Title = “VBApp” ihWnd = FindWindow(0&, Title) ihTask = GetWindowTask(ihWnd) iRet = PostAppMessage(ihTask, WM_QUIT,
When a control is deleted from a form, any code behind that controlis not deleted. It still exists in the code in the General area. Such strandedcode might not be
Designing monitor resolution-independent applications is a frequentproblem Visual Basic programmers face. The simplest solution isto design forms at the 640 by 480 resolution found in most lap-topcomputers. Such a form
The DegreesToXYsubroutine, part of CodeBank’s standard procedurelibrary, calculates the X (horizontal) and Y (vertical) coordinatesof any point, measured in degrees, on the circumference of a circleor ellipse. As you can
You cannot use the IsEmpty function to determine if a variableof type Form or any Object has been assigned a value. You can,however, use this method to determine if the
When you’re finished tinkering with your apps, close and restart VBbefore making the final EXE. This simple action can reduce the size ofyour EXE by 10 to 30 percent (many
You cannot load a VB4 form in VB3 directly. You must modify theform definition. When you open a VB4 form, the file will resemblethe example: VERSION 4.00Begin VB.Form Form1 Caption
Programmers are in the habit of creating meaningful identifiersby concatenating the words of a “title case” phrasethat describes the identifier, such as LastName or FinalPaymentDate.Often, you can use these names
I needed a way to issue a DoEvents to allow Windows time to redraw controlson a form, but wanted to prevent the user from clicking some other controlwithin my application.
In many cases, it is best to select or highlight the full text of afield when that field gains the focus. This allows the user to simply begintyping to replace
When using the SQL Server ODBC driver and SQL Server, and If ODBC preparedexecution is used, certain floating-point values may be incorrectly converted.Microsoft Access and Microsoft Visual Basic commonly use
One way to test whether a specific file exists is to open thefile for input and check VB’s error flag. An error will occurif the file does not exist. Use
Never, never, never assume that a given API call or control/OCXworks the same under Win95 and Windows NT. For example, the 32-bitfile common dialog handles long file names, right? Well,
The Microsoft Access engine will maintain a persistent connection onan ODBC connection in order to be more efficient, even after using a Closemethod on a database opened with ODBC. The
With the release of VB4 and the new development environment for32-bit operating systems, I use three versions of Visual Basicin developing VB applications. Some of my clients won’t acceptapps built
There is a list of our new functions in Visual Basic 4.0 for workingwith an application’s Windows registry entries (or .INI file on16-bit Windows platforms): GetSetting(appname, section, key[, default]) GetAllSettings(appname,
The problem? You want to print a single sub but VB always prints allthe subs that are in the current form. You could copy it to the clipboardand print it
LenLongestWord finds the length of the longest word in a stringwhere a word is defined to be bounded by spaces or the ends ofthe string. It also illustrates a case
Note that in writing in VB3.0, Visual Basic’s AppActivate statementfails to make a 32-bit application the active window under Windows NT.For example: Sub Form_Load () AppActivate “Notepad – (Untitled)”End Sub
Many times when I code similar syntax with slight modifications on each line, I like to make a template of thecore syntax, quickly paste a copy of it however many
When you get a cool sample of a VB component and you simply can’t recreate all of its characteristics inyour app, don’t go nuts. Most of the time, you can
After a call to a DLL, the return value often contains a null.One way to eliminate the null is to look for Chr$(0), as in theexample: Dim CheckForNull As IntegerCheckForNull
There is a simple way to get Monitor resolutions through a WinAPIcall. Declare this in a module: Declare Function GetsystemMetrics Lib “User” (ByVal _ nIndex As Integer) As Integer And
Public Sub UnloadAll()Dim f As Integerf = Forms.CountDo While f > 0 Unload Forms(f – 1) ‘ If form isn’t unloaded exit (User had canceled…) If f = Forms.Count Then
You say you want to use a tab control, but you have so many topics thetabs will be unreadable? Try using a list box in conjunction with a controlarray of
When you are looking at code that calls a function or procedure andyou are not sure in which module the function or procedure is defined,you can highlight/procedure name and press
This code is reusable and small enough to paste into whatever you’redoing and instantly have a form that has no need for a title bar. In thegeneral declarations section, insert