本文以实例讲述了Delphi实现图像文本旋转特效的解决方法，在本程序中利用的控件主要是Panel 控件、Image 控件、Edit 控件、Label 控件和Button 控件。本程序的关键是利用Delphi 的bmp_rotate()函数来实现旋转图像的功能。并巧妙地调用相关Windows API 函数来实现对文本的旋转特效。
完整的实例代码如下：
unit Unit1;interfaceusesWindows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,math,StdCtrls, ExtCtrls;typeTForm1 = class(TForm)Edit1: TEdit;Image1: TImage;bmprotate: TButton;Label1: TLabel;Panel1: TPanel;Image2: TImage;Panel2: TPanel;Image3: TImage;Edit2: TEdit;RotatedText: TButton;Label2: TLabel;procedure bmprotateClick(Sender: TObject);procedure RotatedTextClick(Sender: TObject);procedure FormCreate(Sender: TObject);private{ Private declarations }public{ Public declarations }procedure bmp_rotate(src,dst:Tbitmap;angle:extended);Procedure DrawRotatedText(TheCanvas : TCanvas; TheAngle : Integer;TheText : String);end;varForm1: TForm1;implementation{$R *.DFM}procedure TForm1.bmp_rotate(src,dst:Tbitmap;angle:extended);//图像旋转varc1x,c1y,c2x,c2y:integer;p1x,p1y,p2x,p2y:integer;radius,n:integer;alpha:extended;c0,c1,c2,c3:tcolor;beginangle := (angle / 180) * pi; //将文本框内的内容转换角度c1x := src.Width div 2;c1y := src.Height div 2;c2x := dst.Width div 2;c2y := dst.Height div 2;if c2x < c2y thenn := c2yelsen := c2x;dec (n,1); //使n 值减少1,n:=n-1for p2x := 0 to n do beginfor p2y := 0 to n do beginif p2x = 0 thenalpha:= pi/2elsealpha := arctan2(p2y,p2x);radius := round(sqrt((p2x*p2x)+(p2y*p2y)));//设置旋转时的半径大小p1x := round(radius * cos(angle+alpha)); //设置旋转时的圆心横坐标p1y := round(radius * sin(angle+alpha)); //设置旋转时的圆心纵坐标c0 := src.Canvas.pixels[c1x+p1x,c1y+p1y];//替换图像相关坐标处的像素c1 := src.Canvas.pixels[c1x-p1x,c1y-p1y];c2 := src.Canvas.pixels[c1x+p1y,c1y-p1x];c3 := src.Canvas.pixels[c1x-p1y,c1y+p1x];dst.Canvas.pixels[c2x+p2x,c2y+p2y]:=c0; //置换不同位置的像素点dst.Canvas.pixels[c2x-p2x,c2y-p2y]:=c1;dst.Canvas.pixels[c2x+p2y,c2y-p2x]:=c2;dst.Canvas.pixels[c2x-p2y,c2y+p2x]:=c3;end;application.processmessages //响应其他的消息请求end;end;procedure TForm1.bmprotateClick(Sender: TObject);VarRAngle : Extended;beginRAngle := StrToFloat(Edit1.Text); //设置旋转的角度bmp_rotate(Image1.Picture.bitmap,Image2.Picture.bitmap, RAngle);//运行旋转函数，旋转图形end;Procedure TForm1.DrawRotatedText(TheCanvas : TCanvas; TheAngle : Integer;TheText : String);varlf : TLogFont;tf : TFont;beginImage3.Canvas.refresh;with TheCanvas do beginFont.Name:='Arial';Font.Size:=18;Brush.Style:= bsClear;tf:= TFont.Create;trytf.Assign(Font);GetObject(tf.Handle, Sizeof(lf), @lf); //将当前实例句柄赋给tf 这个Font 对象lf.lfEscapement:=TheAngle*10;lf.lfOrientation := TheAngle * 10; //使输入时的横坐标线与水平线呈所指定的角度tf.Handle := CreateFontIndirect(lf); //创建一个Font 具体对象Font.Assign(tf); //使这个对象运用到程序中finallytf.Free; //释放对象end;TextOut(Image3.left, Image3.top+20 , TheText); //绘制文本到指定区域end;end;procedure TForm1.RotatedTextClick(Sender: TObject);VarTheAngle : Integer;beginTheAngle := StrToInt(Edit2.Text); //将文本框中的文本转换角度DrawRotatedText(Image3.Canvas, TheAngle, 'Delphi图形工作室'); //调用旋转文本函数end;procedure TForm1.FormCreate(Sender: TObject);vartf : TFont;theText:string;begintheText:='Delphi图形工作室'; //设置文本with Image3.Canvas dobeginFont.Name := 'Arial'; //设置字体Font.Size := 18; //设置字体大小Brush.Style := bsClear; //设置笔刷样式tf:= TFont.Create; //创建一个Font 具体对象TextOut(Image3.left, Image3.top+20 , TheText); //绘制文本到指定区域end;end;end.