{ 在网上看到个这个例子感觉还不错,将它移到自己的博客里没事的时候看看; TRect 作用:保存一个矩形的左上角和右下角的坐标值; 声明: type TRect = packed record case integer of 0:(Left, Top, Right, Botton:Integer); 1:(TopLeft, BottonRight:TPoint); end; 由上面的TRect可知,TRect是一个记录类型(TRect),保存了矩形的左上角右下角两个点,4个坐标 或2个点的值。 这个声明是Record类型使用Case子句的典型的例子。 当我们通TopLeft和BottonRight两个点创建矩形时,可以传递两个TPoint值或用Point函数产生他们; } unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); var rectangle1, rectangle2:TRect; begin //用Rectangle来手工设置一个矩形; Rectangle1.Left := 0; rectangle1.Top := 0; rectangle1.Right := 40; rectangle1.Bottom := 60; //再用Rect函数设置第二个矩形; Rectangle2 := Rect(Point(20, 40), Point(60, 80)); //显示每个矩形的左上角和左下角的坐标 ShowMessageFmt('Rectangle 1 coords = %d, %d, %d, %d', [rectangle1.left, rectangle1.top, rectangle1.Right, rectangle1.Bottom]); ShowMessageFmt('Rectangle 2 coords = %d, %d, %d, %d', [rectangle2.Left, rectangle2.Top, rectangle2.Right, rectangle2.Bottom]); end; end.
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