VB6 Tutorial 49: Named Constants
The Visual Basic 6 language provides so many built-in constants that save your time and effort for programming.
The Constants start with the "vb" string, for example, vbRed. And you know about the color constants if you’ve read the previous lessons. The named constants are also known as symbolic constants. They have predefined values defined in the VB language.
QuickHint:
You can use the Object Browser to find the full list of named constants available in Visual Basic. Press F2 in the IDE to open the object browser.
This lesson will only cover more commonly used items. However, you'll notice that in the Object Browser, there are many, many more available to help you save time!
Color constants
These constants belong to the "ColorConstants" enumeration. (Search "ColorConstants" in the Object Browser)
- vbBlack
- vbBlue
- vbCyan
- vbGreen
- vbMagenta
- vbRed
- vbWhite
- vbYellow
These color constants have their long values, for instance, the vbYellow has the long value 65535. It’s hard to remember the numeric values, while the constants are a lot easier, and the code becomes more readable too.
For code examples about color properties, see Common Properties 1 of 3.
Alignment constants
The alignment constants are vbCenter, vbLeftJustify, vbRightJustify.
Button constants
Button constants include vbButtonGraphical, vbButtonStandard that represent graphical and standard appearance of command button respectively.
CheckBox constants
The constants that relate to the CheckBox control are vbChecked, vbUnchecked and vbGrayed constants that are respectively the checked check value, unchecked check value and grayed check value to express the states of the CheckBox control.
Constants from the "Constants" module
- vbBack: Backspace character, equivalent to Chr(8).
- vbCr: Carriage return character without line feed, equivalent to Chr(13).
- vbCrLf: Carriage return & line feed combination, Chr(13)+Chr(10).
- vbFormFeed: Constant for Form Feed, Chr(12).
- vbLf: Constant for line-feed without carriage-return, Chr(10).
- vbNewLine: Constant for new line, this is platform specific.
- vbNullChar: Single null character, Chr(0).
- vbNullString: Constant for null string.
- vbObjectError: Constant which indicates that an error is being returned from a Visual Basic object.
- vbTab: The Tab key, Chr(9).
- vbVerticalTab: Vertical Tab character, Chr(11).
FormShow Constants
- vbModal: Modal form
- vbModeless: Modeless form
MouseButton constants
- vbLeftButton: Left mouse button
- vbMiddleButton: Middle mouse button
- vbRightButtom: Right mouse button
QueryUnload constants
The QueryUnload constants are useful when you take a QueryUnload event in your program. The QueryUnload constants are as follows:
- vbAppTaskManager: When task manager is closing the application.
- vbAppWindows: When current windows session is ending.
- vbFormCode: when Unload method is invoked from code.
- vbFormControlMenu: When the user is closing the application from the Control menu box, pressing the close button.
- vbFormMDIForm: When the MDI parent form is closing while the MDI child form also closes automatically.
- vbFormOwner: The owner of the form is closing the application.
Shift constants
- vbAltMask: Alt key bit mask
- vbCtrlMask: Ctrl key bit mask
- vbShiftMask: Shift key bit mask
System color constants
There are so many system color constants in VB6. Look up in the Object Browser. (Search "SystemColorConstants")
Only few of them are shown below.
- Vb3DFace
- Vb3DHighlight
- Vb3DLight
- Vb3DShadow
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