Delphi实现图像文本旋转特效完整实例代码

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WindowsAPI函数来实现对文本的旋转特效。

完整的实例代码如下：

unitUnit1;
interface
uses
Windows,Messages,SysUtils,Classes,Graphics,Controls,Forms,Dialogs,math,
StdCtrls,ExtCtrls;
type
TForm1=class(TForm)
Edit1:TEdit;
Image1:TImage;
bmprotate:TButton;
Label1:TLabel;
Panel1:TPanel;
Image2:TImage;
Panel2:TPanel;
Image3:TImage;
Edit2:TEdit;
RotatedText:TButton;
Label2:TLabel;
procedurebmprotateClick(Sender:TObject);
procedureRotatedTextClick(Sender:TObject);
procedureFormCreate(Sender:TObject);
private
{Privatedeclarations}
public
{Publicdeclarations}
procedurebmp_rotate(src,dst:Tbitmap;angle:extended);
ProcedureDrawRotatedText(TheCanvas:TCanvas;TheAngle:Integer;
TheText:String);
end;
var
Form1:TForm1;
implementation
{$R*.DFM}
procedureTForm1.bmp_rotate(src,dst:Tbitmap;angle:extended);//图像旋转
var
c1x,c1y,c2x,c2y:integer;
p1x,p1y,p2x,p2y:integer;
radius,n:integer;
alpha:extended;
c0,c1,c2,c3:tcolor;
begin
angle:=(angle/180)*pi;//将文本框内的内容转换角度
c1x:=src.Widthdiv2;
c1y:=src.Heightdiv2;
c2x:=dst.Widthdiv2;
c2y:=dst.Heightdiv2;
ifc2x<c2ythen
n:=c2y
else
n:=c2x;
dec(n,1);//使n值减少1,n:=n-1
forp2x:=0tondobegin
forp2y:=0tondobegin
ifp2x=0then
alpha:=pi/2
else
alpha:=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;
procedureTForm1.bmprotateClick(Sender:TObject);
Var
RAngle:Extended;
begin
RAngle:=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;
ProcedureTForm1.DrawRotatedText(TheCanvas:TCanvas;TheAngle:Integer;
TheText:String);
var
lf:TLogFont;
tf:TFont;
begin
Image3.Canvas.refresh;
withTheCanvasdobegin
Font.Name:="Arial";
Font.Size:=18;
Brush.Style:=bsClear;
tf:=TFont.Create;
try
tf.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
finally
tf.Free;//释放对象
end;
TextOut(Image3.left,Image3.top+20,TheText);//绘制文本到指定区域
end;
end;
procedureTForm1.RotatedTextClick(Sender:TObject);
Var
TheAngle:Integer;
begin
TheAngle:=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;
procedureTForm1.FormCreate(Sender:TObject);
var
tf:TFont;
theText:string;
begin
theText:="Delphi图形工作室";//设置文本
withImage3.Canvasdo
begin
Font.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.