> Date: Thu, 26 Jul 2007 07:52:45 -0500
> From: "Nesler, Thomas J" <[EMAIL PROTECTED]>
> Subject: RE: Changing a canvas's Style property to Bold
> and back To: "Borland's Delphi Discussion List"
> <[email protected]> Message-ID:
>
> <[EMAIL PROTECTED]
> rporate.amfam.com>
>
> Content-Type: text/plain; charset="us-ascii"
>
> Thanks to all for your help. I did look at the Delphi 5
> help but there is no mention that you need to surround the
> style types with brackets.
>
> Tom Nesler
Tom,
TFontStyles is a set. There are defined ways to manage sets
and their elements.
Clipped directly from d7.hlp is:
<paste>
type
TFontStyle = (fsBold, fsItalic, fsUnderline, fsStrikeOut);
TFontStyles = set of TFontStyle;
procedure Form1.Button1Click(Sender: TObject);
begin
Label1.Font.Style := [fsBold,fsUnderline];
end;
A set is a collection of values of the same ordinal type.
The values have no inherent order, nor is it meaningful for
a value to be included twice in a set.
The range of a set type is the power set of a specific
ordinal type, called the base type; that is, the possible
values of the set type are all the subsets of the base type,
including the empty set. The base type can have no more than
256 possible values, and their ordinalities must fall
between 0 and 255. Any construction of the form
set of baseType
where baseType is an appropriate ordinal type, identifies a
set type.
Because of the size limitations for base types, set types
are usually defined with subranges. For example, the
declarations
type
TSomeInts = 1..250;
TIntSet = set of TSomeInts;
create a set type called TIntSet whose values are
collections of integers in the range from 1 to 250. You
could accomplish the same thing with
type TIntSet = set of 1..250;
Given this declaration, you can create a sets like this:
var Set1, Set2: TIntSet;
...
Set1 := [1, 3, 5, 7, 9];
Set2 := [2, 4, 6, 8, 10]
You can also use the set of ... construction directly in
variable declarations:
var MySet: set of 'a'..'z';
...
MySet := ['a','b','c'];
Other examples of set types include
set of Byte
set of (Club, Diamond, Heart, Spade)
set of Char;
The in operator tests set membership:
if 'a' in MySet then ... { do something } ;
Every set type can hold the empty set, denoted by [].
</ paste>
Sets can be confusing at first but that is because they are
so powerful and useful.
Mick
_______________________________________________
Delphi mailing list -> [email protected]
http://www.elists.org/mailman/listinfo/delphi
