相关资料:
http://blog.qdac.cc/?p=1161
实例代码:

1 unit Unit1; 2
3 interface
4
5 uses
6 System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants, 7 FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, 8 FMX.Controls.Presentation, FMX.StdCtrls, FMX.ScrollBox, FMX.Memo; 9
10 type
11 TForm1 = class(TForm) 12 Button1: TButton; 13 Label2: TLabel; 14 Memo1: TMemo; 15 procedure Button1Click(Sender: TObject); 16 private
17 { Private declarations }
18 public
19 { Public declarations }
20 end; 21
22 var
23 Form1: TForm1; 24
25 implementation
26 uses
27 FMX.BehaviorManager;//需要引入
28 {$R *.fmx}
29 {$R *.LgXhdpiPh.fmx ANDROID}
30 {$R *.Surface.fmx MSWINDOWS}
31
32 procedure TForm1.Button1Click(Sender: TObject); 33 var
34 DeviceBehavior: IDeviceBehavior; 35 DisplayMetrics: TDeviceDisplayMetrics; 36 begin
37 if TBehaviorServices.Current.SupportsBehaviorService(IDeviceBehavior, DeviceBehavior, Self) then
38 begin
39 DisplayMetrics := DeviceBehavior.GetDisplayMetrics(Self); 40 Memo1.Lines.Add('物理分辨率:'); 41 Memo1.Lines.Add(IntToStr(DisplayMetrics.PhysicalScreenSize.cx) + 'x' + IntToStr(DisplayMetrics.PhysicalScreenSize.cy)); 42 Memo1.Lines.Add('屏幕尺寸:'); 43 Memo1.Lines.Add( 44 FloatToStr(sqrt( 45 DisplayMetrics.PhysicalScreenSize.cx * DisplayMetrics.PhysicalScreenSize.cx / DisplayMetrics.PixelsPerInch / DisplayMetrics.PixelsPerInch +
46 DisplayMetrics.PhysicalScreenSize.cy * DisplayMetrics.PhysicalScreenSize.cy / DisplayMetrics.PixelsPerInch / DisplayMetrics.PixelsPerInch))); 47 Memo1.Lines.Add('PPI:'); 48 Memo1.Lines.Add(FloatToStr(DisplayMetrics.PixelsPerInch)); 49 end; 50 end; 51
52 end.