再學 GDI+[41]: 文本輸出 - 控制輸出字符的個數

本例效果圖:

　　代碼文件:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs;
type
　TForm1 = class(TForm)
　　procedure FormPaint(Sender: TObject);
　　procedure FormClick(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ,GDIPAPI;
var
　pc: PChar = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
　num: Integer;
procedure TForm1.FormPaint(Sender: TObject);
var
　g: TGPGraphics;
　b: TGPBrush;
　font: TGPFont;
begin
　g := TGPGraphics.Create(Canvas.Handle);
　b := TGPSolidBrush.Create(aclGoldenrod);
　font := TGPFont.Create('Arial Black', 18, FontStyleRegular);
　
　{參數 2 為輸出字符的個數, -1 表示全部輸出}
　g.DrawString(pc, num, font, MakePoint(5.0, 5), b);
　b.Free;
　font.Free;
　g.Free;
end;
procedure TForm1.FormClick(Sender: TObject);
var
　i,n: Integer;
begin
　n := Length(pc);
　num := 0;
　for i:= 1 to n do
　begin
　　num := i;
　　Repaint;
　　Sleep(100);
　　Application.ProcessMessages;
　end;
　num := -1;
　for i:= 1 to Length(pc) do
　begin
　　Inc(pc);
　　Repaint;
　　Sleep(100);
　　Application.ProcessMessages;
　end;
　Dec(pc,n);
end;
end.窗體文件:object Form1: TForm1
　Left = 0
　Top = 0
　Caption = 'Form1'
　ClIEntHeight = 42
　ClIEntWidth = 501
　Color = clBtnFace
　Font.Charset = DEFAULT_CHARSET
　Font.Color = clWindowText
　Font.Height = -11
　Font.Name = 'Tahoma'
　Font.Style = []
　OldCreateOrder = False
　Position = poDesktopCenter
　OnClick = FormClick
　OnPaint = FormPaint
　PixelsPerInch = 96
　TextHeight = 13
end