请教下如何画圆啊?在线等!! 要求是就是鼠标开始下压的那个点为圆心坐标,移动后的点为圆上的一个点,半径就是这两个点的距离!谢谢了! 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs,jpeg,ExtCtrls, StdCtrls;type TForm1 = class(TForm) procedure FormMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure FormMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer); private fselecting:boolean; fbeginpt,fendpt:tpoint; { Private declarations } public { Public declarations } end;var Form1: TForm1;implementation{$R *.dfm}procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);begin fselecting:=true; fbeginpt:=Form1.ScreenToClient(mouse.CursorPos);end;procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);begin fselecting:=false; fendpt:=Form1.ScreenToClient(mouse.CursorPos); Self.Repaint;end;procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);begin fendpt:=Form1.ScreenToClient(mouse.CursorPos); if fselecting then begin Canvas.FillRect(Canvas.ClipRect); //Canvas.Rectangle(rect(fbeginpt,fendpt)); canvas.Ellipse(rect(fbeginpt,fendpt)); canvas.Pen.Color:=clred; Canvas.Pen.Width:=1; end;end;end. 用控件 托拽就可以了 就这么简单用visual graph来做 怎样保存按钮组?类似TStringList 清除"我最近的文档"的记录 代码实现 一道送分题! 在线等待!!!!!!!!!!! 这是什么问题:内在的OLE自动化错误? 一个只能下载文件的web服务器 如何用idhttp下载一个网页到d:\ 窗体在游戏里弹出,不失真!如何做!快快快! 当代中国大学毕业生地悲哀-人事局强行扣留毕业生档案,是何道理? FastReport要如何实现这种效果 ★★☆☆ 100分求解,帮我up也有分 ☆☆★★ LPWSTR问题求助 收购成熟进销存和库存管理源代码
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs,jpeg,ExtCtrls, StdCtrls;type
TForm1 = class(TForm)
procedure FormMouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
procedure FormMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
private
fselecting:boolean;
fbeginpt,fendpt:tpoint;
{ Private declarations }
public
{ Public declarations }
end;var
Form1: TForm1;implementation{$R *.dfm}procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
fselecting:=true;
fbeginpt:=Form1.ScreenToClient(mouse.CursorPos);
end;
procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
fselecting:=false;
fendpt:=Form1.ScreenToClient(mouse.CursorPos);
Self.Repaint;
end;
procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
begin
fendpt:=Form1.ScreenToClient(mouse.CursorPos);
if fselecting then
begin
Canvas.FillRect(Canvas.ClipRect);
//Canvas.Rectangle(rect(fbeginpt,fendpt));
canvas.Ellipse(rect(fbeginpt,fendpt));
canvas.Pen.Color:=clred;
Canvas.Pen.Width:=1;
end;
end;end.
用visual graph来做