A set of functions that dialog data verification (DDV) employs to validate user entries in a dialog control. For example, the function DDV_MaxChars could validate that the string entered in the text-box control is not greater than a specified length.
In programming, a named storage location capable of containing a certain type of data that can be modified during program execution. See also data structure, data type.
A custom control that can be used in Visual Basic as well as other Microsoft programming systems, including Visual C++. VBX controls are 16-bit dynamic-link libraries and are not supported in 32-bit applications. Visual Basic control files have a .VBX filename extension.
A scalable font in which the characters are drawn in arrangements of line segments rather than arrangements of curves or bits. Vector fonts are often used in applications that are optimized for output to plotters instead of printers. See also raster font, TrueType font.
A database of the names of almost every menu item on thousands of Gopher servers. This database can be searched from most major gopher menus. See also Archie.
An application's company and product identification, product release number, and copyright and trademark notification. Version information is held in a standard form in the executable (.EXE) file or dynamic-link library (DLL) file and is accessible by various tools and Windows functions.
A resource that contains either text or binary data about an application's version information.
A database of the names of almost every menu item on thousands of Gopher servers. This database can be searched from most major gopher menus. See also Archie.
Program for opening image files and files in other special formats, such as audio and video.
A rectangle in device space that is used to specify a transformation between page and device space. The viewport extents (height and width) are always measured in pixels for a video display or in dots for printers.
The corner of the viewport from which the height and width of the viewport are measured.
In an accelerator table resource, a flag used to indicate that the keystroke value in the definition is a virtual key code.
A base class whose derived classes contain only one shared instance of its members even if the indirectly derived classes have done multiple inheritance. The class declaration for the derived class must have the keyword virtual before the base class specifier in order for it to be a virtual base class. In the following example, class MultiC has only one subobject of class Base even though it has inherited from more than one class derived from Base:
class Base { };
class DerivedA: virtual public Base { };
class DerivedB: virtual public Base { };
class MultiC: public DerivedA, public DerivedB { };
A destructor implemented by declaring a base class's destructor with the keyword virtual. A virtual destructor ensures that, when delete is applied to a base class pointer or reference, it calls the destructor implemented in the derived class, if an implementation exists.
A low-level software component that manages a single resource, such as a display screen or a serial port, on behalf of all running processes. A VxD is always 32-bit protected mode code and is frequently written in assembly language.
A member function of a base class, where the function is declared with the keyword virtual. If a base class contains a virtual function and a derived class defines the same function, the function from the derived class is invoked for objects of the derived class, even if it is called using a pointer or reference to the base class.
A table of function pointers, such as an implementation of a class in C++. The pointers in the VTBL point to the members of the interfaces that an object supports. See also dual interface.
In C++, a method of deriving classes by preceding the name of the base class with the keyword virtual. With virtual inheritance, indirectly derived classes contain only one shared instance of the base class's members even if they have done multiple inheritance. See also virtual base class.
In Windows, a device-independent value translated from the scan code by the keyboard device driver. The code identifies the keyboard key. See also VIRTKEY.
A memory-management scheme that allows an application to "see" a large, continuous block of primary memory (RAM) that, in reality, is a much smaller block of primary memory supplemented by secondary memory (such as a hard disk), with blocks of data being moved into and out of primary memory. See also swap file.
A vector-based language for modeling three-dimensional environments. It sends ASCII text files over the Internet, which are translated by the VRML viewing engine at the other end. VRML complements HTML.
In Windows, the portion of a window visible to the user.
A custom control that can be used in Visual Basic as well as other Microsoft programming systems, including Visual C++. VBX controls are 16-bit dynamic-link libraries and are not supported in 32-bit applications. Visual Basic control files have a .VBX filename extension.
A pointer to an object of unknown type. See also typed pointer.
A vector-based language for modeling three-dimensional environments. It sends ASCII text files over the Internet, which are translated by the VRML viewing engine at the other end. VRML complements HTML.
A table of function pointers, such as an implementation of a class in C++. The pointers in the VTBL point to the members of the interfaces that an object supports. See also dual interface.
A low-level software component that manages a single resource, such as a display screen or a serial port, on behalf of all running processes. A VxD is always 32-bit protected mode code and is frequently written in assembly language.