Computer Programming Concepts and Visual Basic David I. Schneider

446 Computer Programming Concepts and Visual Basic
followed on subsequent lines by one or more statements for carrying out the task of the procedure,
and ending with the statement End Property. The parameter list parList is a list of
variables through which values will be passed to the procedure when an assignment is made
to the property of an associated object. The name and data type of each parameter in a Property
Let procedure must be the same as the corresponding parameter in a Property Get procedure
(if one exists).
PSET The graphics method objectName.PSet(x, y) displays the point with coordinates (x, y)
in the foreground color. The method objectName.PSet(x, y), c causes the point (x, y) to be
displayed in the RGB color specified by c. The size of the point is determined by the value
of the DrawWidth property. The actual color(s) displayed depend on the values of the Draw-
Mode and DrawStyle properties. After a PSet method is executed, the value of object-
Name.CurrentX becomes x and the value of objectName.CurrentY becomes y. [color]
[coordinate systems]
PUT The Put statement is used to place data into a random-access file. Suppose recVar is a
variable of a user-defined record type and that a file has been opened with a statement of the
form Open fileName For Random As #n Len = Len(recVar). The statement Put #n, r, recVar
places the value of recVar in the rth record of the file.
The Put statement is also used to place data into a file opened as a binary file. Suppose
var is a variable that holds a value consisting of b bytes. (For instance, if var is an integer
variable, then b is 2. If var is an ordinary string variable, then b will equal the length of the
string currently assigned to it.) The statement Put #n, p, var writes the successive bytes of
var into the b consecutive locations beginning with position p in the binary file with reference
number n. (Note: The positions are numbered 1, 2, 3, . . . .) If p is omitted, the current
file position is used as the beginning position. [binary file]
QBCOLOR The function QBColor provides easy access to 16 standard colors. If colorAttrib
is a whole number from 0 to 15, the value of the functions QBColor (colorAttrib) is the
RGB color number associated with colorAttrib. The following table names the colors produced
by each of the possible values of colorAttrib.
0 Black 4 Red 8 Gray 12 Light Red
1 Blue 5 Magenta 9 Light Blue 13 Light Magenta
2 Green 6 Brown 10 Light Green 14 Yellow
3 Cyan 7 White 11 Light Cyan 15 Intense White
RAISEEVENT After an event has been declared in the general declarations section of a
class module, the statement RaiseEvent EventName(arg1, arg2, . . .) generates the event.
RANDOMIZE The statement Randomize automatically uses the computer’s clock to seed
the random-number generator. If a program includes a Randomize statement in the
Form_Load event procedure, the list of numbers generated by Rnd will vary each time the
program is executed. Randomize n seeds the generator with a number determined by n. If a
program does not seed the random-number generator or seeds it with a set number, the list
of numbers generated by Rnd will be the same each time the program is executed.
RECORDCOUNT The value of Data1.Recordset.RecordCount is the number of records in
the database table associated with the data control.
RECORDSOURCE The value of the RecordSource property of a data control is the table of
the database determined by the DatabaseName property. The value can also be an SQL statement
used to specify a virtual table.
REDIM The statement ReDim arrayName(...) erases the array from memory and recreates
it. The information inside the parentheses has the same form and produces the same results
as that in a Dim statement. After the ReDimensioning, all elements have their default values.
Although the ranges of the subscripts may be changed, the number of dimensions must be