Android实例-屏幕操持常亮(XE8+小米2)

相关资料：

http://www.bubuko.com/infodetail-163304.html

结果：

1.打开权限Wake lock为True。

第三方单元：

 unit Android.JNI.PowerManager;

 interface

 function AcquireWakeLock : Boolean;
 procedure ReleaseWakeLock;

 implementation

 uses
   System.SysUtils,
   Androidapi.Helpers,
   Androidapi.JNI,
   Androidapi.JNIBridge,
   Androidapi.JNI.GraphicsContentViewText,
   Androidapi.JNI.JavaTypes,
   FMX.Helpers.Android;

 type
   JPowerManager = interface;
   JWakeLock = interface;
   JWakeLockClass = interface(JObjectClass)
   ['{918E171F-CDB8-4464-9507-F49272CE7636}']
   end;

   [JavaSignature('android/os/PowerManager$WakeLock')]
   JWakeLock = interface(JObject)
   ['{D17B1136-FA15-4AEB-85B1-2D490F0FD320}']
     {Methods}
     procedure acquire; cdecl;
     procedure release; cdecl;
     function isHeld: Boolean; cdecl;
   end;

   TJWakeLock = class(TJavaGenericImport<JWakeLockClass, JWakeLock>) end;
   JPowerManagerClass = interface(JObjectClass)
   ['{7D0696A2-ADEA-4158-AE1F-5E720DEDBCF9}']
     {Property methods}
     function _GetFULL_WAKE_LOCK: Integer; cdecl;
     function _GetSCREEN_BRIGHT_WAKE_LOCK: Integer; cdecl;
     function _GetSCREEN_DIM_WAKE_LOCK: Integer; cdecl;
     function _GetPARTIAL_WAKE_LOCK: Integer; cdecl;
     {Properties}
     //Keep screen on bright & keyboard on
     //Deprecated in API level 17 - Jelly Bean MR1
     property FULL_WAKE_LOCK: Integer read _GetFULL_WAKE_LOCK;
     //Keep screen on bright
     //Deprecated in API level 13 - Honeycomb MR2
     property SCREEN_BRIGHT_WAKE_LOCK: Integer read _GetSCREEN_BRIGHT_WAKE_LOCK;
     //Keep screen on dim
     //Deprecated in API level 17 - Jelly Bean MR1
     property SCREEN_DIM_WAKE_LOCK: Integer read _GetSCREEN_DIM_WAKE_LOCK;
     //Keep CPU running, screen & keyboard can go off
     property PARTIAL_WAKE_LOCK: Integer read _GetPARTIAL_WAKE_LOCK;
   end;

   [JavaSignature('android/os/PowerManager')]
   JPowerManager = interface(JObject)
   ['{DEAED658-4353-4D17-B0A3-8179E48BE87F}']
     {Methods}
     function newWakeLock(levelAndFlags: Integer; tag: JString): JWakeLock; cdecl;
   end;

   TJPowerManager = class(TJavaGenericImport<JPowerManagerClass, JPowerManager>) end;

   function GetPowerManager: JPowerManager;
   var
     PowerServiceNative: JObject;
   begin
     PowerServiceNative := SharedActivityContext.getSystemService(
       TJContext.JavaClass.POWER_SERVICE);
     if not Assigned(PowerServiceNative) then
       raise Exception.Create('Could not locate Power Service');
     Result := TJPowerManager.Wrap(
       (PowerServiceNative as ILocalObject).GetObjectID);
     if not Assigned(Result) then
       raise Exception.Create('Could not access Power Manager');
   end;

 var
   WakeLock: JWakeLock = nil;
   function AcquireWakeLock: Boolean;
   var
     PowerManager: JPowerManager;
   begin
     Result := Assigned(WakeLock);
     if not Result then
     begin
       PowerManager := GetPowerManager;
       WakeLock := PowerManager.newWakeLock(
         TJPowerManager.JavaClass.SCREEN_BRIGHT_WAKE_LOCK,
         StringToJString('Runing'));
       Result := Assigned(WakeLock);
     end;
     if Result then
     begin
       if not WakeLock.IsHeld then
       begin
         WakeLock.acquire;
         Result := WakeLock.isHeld
       end;
     end;
   end;

 procedure ReleaseWakeLock;
 begin
   if Assigned(WakeLock) then
   begin
     WakeLock.release;
     WakeLock := nil
   end;
 end;

 end.

实例代码：

 unit Unit1;

 interface

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

 type
   TForm1 = class(TForm)
     Label1: TLabel;
     Button1: TButton;
     Button2: TButton;
     procedure Button1Click(Sender: TObject);
     procedure Button2Click(Sender: TObject);
   private
     { Private declarations }
   public
     { Public declarations }
   end;

 var
   Form1: TForm1;

 implementation
 uses
   Android.JNI.PowerManager;//需要引入
 {$R *.fmx}
 {$R *.NmXhdpiPh.fmx ANDROID}

 procedure TForm1.Button1Click(Sender: TObject);
 begin
   AcquireWakeLock;//获取唤醒锁
 end;

 procedure TForm1.Button2Click(Sender: TObject);
 begin
   ReleaseWakeLock;//释放唤醒锁
 end;

 end.