Computer Programming Concepts and Visual Basic David I. Schneider

CANCEL The Cancel property provides a means of responding when the user presses the
Esc key. At most one command button on a form may have its Cancel property set to True.
If the Esc key is pressed while the program is running, Visual Basic will execute the click
event procedure of the command button whose Cancel property is True.
CAPTION The Caption property holds the text that is to appear as the caption for a form,
command button, data control, or label. If an ampersand (&) is placed in the caption of a
command button or label, the ampersand will not be displayed, but the character following
the ampersand will become an underlined access key. Access keys provide a quick way to
access a command button or the control (usually a text box) following (in tab index order) a
label. Access keys are activated by holding down the Alt key and pressing the access key
character.
CBOOL The function CBool converts byte, currency, double-integer, integer, long integer,
and single-precision numbers to the Boolean values True or False. Nonzero values are converted
to True and zero is converted to False. If x is any number, then the value of CBool(x)
is the Boolean value determined by x.
CBYTE The function CByte converts integer, long integer, single-precision, double-precision,
and currency numbers to byte numbers. If x is any number, then the value of CByte(x)
is the byte number determined by x.
CCUR The function CCur converts byte integer, long integer, single-precision, and doubleprecision
numbers to currency numbers. If x is any number, then the value of CCur(x) is the
currency number determined by x.
CDATE The function CDate converts byte, currency, double-integer, integer, long integer,
and single-precision numbers to dates. If x is any number, then the value of CDate(x) is the
date determined by x.
CDBL The function CDbl converts byte, integer, long integer, single-precision, and currency
numbers to double-precision numbers. If x is any number, then the value of CDbl(x) is the
double-precision number determined by x.
CHANGE The Change event occurs when the contents of a combo box, directory list box,
drive list box, label, picture box, scroll bar, or text box are altered in a specific way. The alterations
are: (a) change of text (combo box or text box), (b) user selects a new directory or
drive (directory and drive list boxes), (c) thumb moves (scroll bar), (d) change of Caption
property (label), and (e) change of Picture property (picture box).
CHDIR The statement ChDir path changes the current directory on the specified disk drive
to the subdirectory specified by path. For example, ChDir “C:\”specifies the root directory
of the C drive as the current directory. Omitting a drive letter in path causes the default drive
to be used. [directories]
CHDRIVE The statement ChDrive drive changes the default drive to the drive specified by
drive. For example, ChDrive “A”specifies the A drive as the new default drive.
CHR If n is a number from 0 to 255, then a statement of the form objectName.Print Chr(n)
displays the nth character of the current font.
CINT The function CInt converts byte, long integer, single-precision, double-precision, and
currency numbers to integer numbers. If x is any number from –32768 to 32767, the value
of CInt(x) is the (possibly rounded) integer constant that x determines.
CIRCLE The graphics method objectName.Circle (x, y), r, c, r1, r2, a draws on objectName
a portion, or all, of an ellipse. The center of the ellipse is the point (x, y) and the longer radius
is r. The color of the ellipse is determined by c. If r1 and r2 are present, then the computer
draws only the portion of the ellipse that extends from the radius line at an angle of Abs(r1)
radians with the horizontal radius line to the radius line at an angle of Abs(r2) radians with
the horizontal radius line in a counterclockwise direction. If either r1 or r2 is negative, the
Appendix C 425