XE 画矩形实现拖拉改变大小（属性）

实现原理：

1.拖一个rectangle控件，Align属性为TOP

2.拖一个Split控件，Align为Top

3.拖Rectangle，Align为Bottom

4.拖Split，Align为Bottom

5.左边、右边依次类推，

6.最后拖一个Rectangle，Align为Client，Stroke属性中的Color为red。

具体代码：

unit UnitCheckIPN;

interface

uses
System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, FMX.StdCtrls,
FMX.Objects, FMX.Controls.Presentation;

type
TForm2 = class(TForm)
RT: TRectangle;  //RectTop
ST: TSplitter;
RL: TRectangle;
SL: TSplitter;
RB: TRectangle;
SB: TSplitter;
RR: TRectangle;
SR: TSplitter;
Rect: TRectangle;
Image1: TImage;
Button1: TButton;
Button2: TButton;
Button3: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
private
{ Private declarations }
procedure SetRect(s:String);
function GetRC: String;                   // 获取   获取当前矩形的位置
procedure SetRC(const Value: String);     // 设置   给定x,y,w,h   矩形自动改变位置
public
{ Public declarations }
property RC: String read GetRC write SetRC;  // 将矩形的值设为属性，读为获取rect的（x,y,width, height）   写时为设置矩形的x,y,w,h
end;

var
Form2: TForm2;

implementation

{$R *.fmx}

procedure TForm2.Button1Click(Sender: TObject);
begin
RC:='103,128,301,203';      //
end;

procedure TForm2.Button2Click(Sender: TObject);
begin
ShowMessage(RC);            //
end;

procedure TForm2.Button3Click(Sender: TObject);
begin
RC:='103,128,394,203';
end;

function TForm2.GetRC: String;
var
x,y,w,h : Single;
begin
result:='';
y:=RT.Height+ST.Height;
h:=Image1.Height - RT.Height - ST.Height - RB.Height - SB.Height;

x:=RL.Width+SL.Width;
w:=Image1.Width-RL.Width-SL.Width-RR.Width-SR.Width;

result:=x.ToString()+','+y.ToString()+','+w.ToString()+','+h.ToString();
end;

procedure TForm2.SetRC(const Value: String);
var
ss: TStringList;
x,y,w,h: Integer;
begin
ss:=TStringList.Create;
ss.CommaText:=Value;
x:=ss[0].ToInteger();
y:=ss[1].ToInteger();
w:=ss[2].ToInteger();
h:=ss[3].ToInteger();
ss.Free;

RT.Height:=y-ST.Height;
RB.Height:=Image1.Height-(RT.Height + ST.Height + h + SB.Height);

RL.Width:=x-SL.Width;
RR.Width:=Image1.Width-(RL.Width+SL.Width+w+SR.Width);
end;

procedure TForm2.SetRect(s: String);
var
ss: TStringList;
x,y,w,h: Integer;
begin
ss:=TStringList.Create;
ss.CommaText:=s;
x:=ss[0].ToInteger();
y:=ss[1].ToInteger();
w:=ss[2].ToInteger();
h:=ss[3].ToInteger();
ss.Free;

RT.Height:=y-ST.Height;
RB.Height:=Image1.Height-(RT.Height + ST.Height + h + SB.Height);

RL.Width:=x-SL.Width;
RR.Width:=Image1.Width-(RL.Width+SL.Width+w+SR.Width);
end;

end.

这里充分理解了属性，见证了属性的强大，好好学习，再接再厉。