Delphi IOS 后台运行

同样的程序，编译成android，锁屏后继续运行正常，蓝牙通讯正常，但在IOS下锁屏后程序的蓝牙就中断通讯了？

IOS的机制就是这样，锁屏就关闭了。

音乐播放器是怎么做到的？锁屏还能继续工作？

 查看iPhone手机，关闭后台刷新，依然可以播放音乐。

另外还有系统设置里的后台刷新打开还是关闭状态。

写个单独的循环累加，显示结果值的程序，加上audio、bluetooth-central、bluetooth-peripheral三个选项，锁屏依然停止状态。看来还是要写线程代码。

delphi的例子MusicPlayer，加上audio选项，锁屏播放正常。不加audio选项，锁屏即停止！如果不加audio，加上bluetooth-central锁屏后报错了。让music支持后台运行正常，主界面上加载一个循环累计变量，锁屏后也是停止运行了，

但是进度条tbProgress是解锁后恢复正常，显示准确的进度，但是我的iii循环累计变量停止接着上次值开始累计了。

只能是后台（线程）运行了。

线程也不行，调试跟踪music，锁屏后，线程所有函数都不执行了。停止了。回复后才读取最新的进度，信息。但是

UIBackgroundModes

 Delphi>Project Options>Version>UIBackgroundModes

http://docwiki.embarcadero.com/RADStudio/Seattle/en/Version_Info

http://community.embarcadero.com/blogs/blog-menu/entry/background-modes-in-ios 

蓝牙Background

http://docwiki.embarcadero.com/RADStudio/Seattle/en/Using_Bluetooth_Low_Energy

audio

location

voip

newsstand-content

external-accessory

bluetooth-central

bluetooth-peripheral

fetch

remote-notification

Information Property List Key Reference

https://developer.apple.com/library/ios/documentation/General/Reference/InfoPlistKeyReference/Articles/iPhoneOSKeys.html#//apple_ref/doc/plist/info/UIBackgroundModes

Background Execution

https://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html

music background run

http://community.embarcadero.com/blogs/blog-menu/blogger/listings/miguel-oliver-embarcadero-com

Communicating with a Bluetooth Accessory

Apps that work with Bluetooth peripherals can ask to be woken up if the peripheral delivers an update when the app is suspended. This support is important for Bluetooth-LE accessories that deliver data at regular intervals, such as a Bluetooth heart rate belt. You enable support for using bluetooth accessories from the Background modes section of the Capabilities tab in your Xcode project. (You can also enable this support by including the UIBackgroundModes key with the bluetooth-central value in your app’s Info.plist file.) When you enable this mode, the Core Bluetooth framework keeps open any active sessions for the corresponding peripheral. In addition, new data arriving from the peripheral causes the system to wake up the app so that it can process the data. The system also wakes up the app to process accessory connection and disconnection notifications.

In iOS 6, an app can also operate in peripheral mode with Bluetooth accessories. To act as a Bluetooth accessory, you must enable support for that mode from the Background modes section of the Capabilities tab in your Xcode project. (You can also enable this support by including the UIBackgroundModes key with the bluetooth-peripheral value in your app’s Info.plist file.) Enabling this mode lets the Core Bluetooth framework wake the app up briefly in the background so that it can handle accessory-related requests. Apps woken up for these events should process them and return as quickly as possible so that the app can be suspended again.

Any app that supports the background processing of Bluetooth data must be session-based and follow a few basic guidelines:

• Apps must provide an interface that allows the user to start and stop the delivery of Bluetooth events. That interface should then open or close the session as appropriate.

• Upon being woken up, the app has around 10 seconds to process the data. Ideally, it should process the data as fast as possible and allow itself to be suspended again. However, if more time is needed, the app can use the beginBackgroundTaskWithExpirationHandler: method to request additional time; it should do so only when absolutely necessary, though.

 CBCentralManagerDelegate

CBCentralManagerDelegate

CBCentralManager

自己要写代码

 https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/AboutCoreBluetooth/Introduction.html

delphi CBCentralManager CBCentralManagerDelegate 

Core Bluetooth Programming Guide

https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/CoreBluetoothBackgroundProcessingForIOSApps/PerformingTasksWhileYourAppIsInTheBackground.html#//apple_ref/doc/uid/TP40013257-CH7-SW1

 https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/CoreBluetoothBackgroundProcessingForIOSApps/PerformingTasksWhileYourAppIsInTheBackground.html

https://developer.apple.com/library/mac/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/CoreBluetoothBackgroundProcessingForIOSApps/PerformingTasksWhileYourAppIsInTheBackground.html

fetch模式

需要执行函数 application:performFetchWithCompletionHandler:

函数定义：

https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIApplicationDelegate_Protocol/index.html#//apple_ref/occ/intfm/UIApplicationDelegate/application:performFetchWithCompletionHandler:

delphi Fetch example

http://stackoverflow.com/questions/32348081/delphi-firemonkey-ios-background-processing

http://qc.embarcadero.com/wc/qcmain.aspx?d=128968

unit uBackgroundiOS;

interface

uses fmx.platform.iOS,iOSapi.CocoaTypes, Macapi.ObjCRuntime, Macapi.ObjectiveC,
     iOSapi.UIKit;

const
  UIBackgroundFetchResultNewData:NSUInteger = 0;
  UIBackgroundFetchResultNoData:NSUInteger = 1;
  UIBackgroundFetchResultFailed:NSUInteger = 2;

  UIApplicationBackgroundFetchIntervalMinimum:NSTimeInterval = 0;
  UIApplicationBackgroundFetchIntervalNever:NSTimeInterval = -1;

type

  // copied from fmx.platform.iOS as it's on private declaration
  id = Pointer;
  SEL = Pointer;
  PUIApplication = Pointer;

  IMP = function( self : id; cmd : SEL; Param1 : NSUInteger ) : id; cdecl;

  function imp_implementationWithBlock( block :id ) : IMP; cdecl; external libobjc name  _PU + 'imp_implementationWithBlock';
  function imp_removeBlock( anImp : IMP ) : integer; cdecl; external libobjc name _PU + 'imp_removeBlock';

  procedure performFetchWithCompletionHandler(self : id; _cmd : SEL; application:    PUIApplication; handler : id );

  procedure initializeBackgroundFetch;

  function objc_msgSend(theReceiver: Pointer; theSelector: Pointer): Pointer; cdecl; varargs;
  external libobjc name _PU + 'objc_msgSend';

  //to test if procedure is called in background
  var fecth_string_test: string;

implementation

procedure performFetchWithCompletionHandler(self : id; _cmd : SEL; application: PUIApplication; handler : id );
var
  ahandlerimp: IMP;
begin
  //Code to perform fetch HERE!!!!
  fecth_string_test := 'entered background code!!';

  ahandlerimp := imp_implementationWithBlock( handler ); //Create c function for block
  ahandlerimp(self,_cmd, UIBackgroundFetchResultNewData); //Call c function, _cmd is ignored
  imp_removeBlock(ahandlerimp); //Remove the c function created two lines up
end;

procedure initializeBackgroundFetch;
Var
  UIApp: UIApplication;
begin
  UIApp := TUIApplication.Wrap(TUIApplication.OCClass.sharedApplication);

  objc_msgSend((UIApp as ILocalObject).GetObjectId,
                sel_getUid('setMinimumBackgroundFetchInterval:'),
                UIApplicationBackgroundFetchIntervalMinimum);

  class_addMethod(objc_getClass('DelphiAppDelegate') ,
                  sel_getUid('application:performFetchWithCompletionHandler:'),
                  @performFetchWithCompletionHandler,
                  'v@:@?');
end;

end.

 delphi10里

unit Macapi.Bluetooth;

 TCBCentralManager = class(TOCGenericImport<CBCentralManagerClass, CBCentralManager>)  end;

  CBCentralManagerDelegate = interface(IObjectiveC)
  ['{1337817E-92DE-4FA9-8CF2-E00E89125A0F}']
    procedure centralManagerDidUpdateState(central: CBCentralManager); cdecl;
    [MethodName('centralManager:willRestoreState:')]
    procedure centralManagerWillRestoreState(central: CBCentralManager; dict: NSDictionary); cdecl;
    [MethodName('centralManager:didRetrievePeripherals:')]
    procedure centralManagerDidRetrievePeripherals(central: CBCentralManager; peripherals: NSArray); cdecl;
    [MethodName('centralManager:didRetrieveConnectedPeripherals:')]
    procedure centralManagerDidRetrieveConnectedPeripherals(central: CBCentralManager; peripherals: NSArray); cdecl;
    [MethodName('centralManager:didDiscoverPeripheral:advertisementData:RSSI:')]
    procedure centralManagerDidDiscoverPeripheral(central: CBCentralManager; peripheral: CBPeripheral;
      advertisementData: NSDictionary; RSSI: NSNumber); cdecl;
    [MethodName('centralManager:didConnectPeripheral:')]
    procedure centralManagerDidConnectPeripheral(central: CBCentralManager; peripheral: CBPeripheral); cdecl;
    [MethodName('centralManager:didFailToConnectPeripheral:error:')]
    procedure centralManagerDidFailToConnectPeripheral(central: CBCentralManager; peripheral: CBPeripheral; error: NSError); cdecl;
    [MethodName('centralManager:didDisconnectPeripheral:error:')]
    procedure centralManagerdidDisconnectPeripheral(central: CBCentralManager; peripheral: CBPeripheral; error: NSError); cdecl;
  end;

unit System.Mac.Bluetooth;

TInternalBluetoothLEManager = class(TOCLocal, CBCentralManagerDelegate)
  private
    FCentralManager: CBCentralManager;
    FOnDeviceDiscovered: TDeviceDiscoveredEvent;
    FWaitingToDiscover: Boolean;
    FIsDiscovering: Boolean;
    FTimer: TInternalTimer;
    FConnected: Boolean;
    FOnDeviceDiscoveryTimeout: TNotifyEvent;
    FLastError: Integer;
    FFilterUUIDList: NSMutableArray;
    FScanOptions: NSMutableDictionary;
    FOnDeviceConnect: TDeviceConnectionChangeEvent;
    FOnDeviceDisconnect: TDeviceConnectionChangeEvent;
    procedure CreateTimer(Interval: Integer);
  public
    constructor Create;
    destructor Destroy; override;
    procedure centralManagerDidUpdateState(central: CBCentralManager); cdecl;
    [MethodName('centralManager:willRestoreState:')]
    procedure centralManagerWillRestoreState(central: CBCentralManager; dict: NSDictionary); cdecl;
    [MethodName('centralManager:didRetrievePeripherals:')]
    procedure centralManagerDidRetrievePeripherals(central: CBCentralManager; peripherals: NSArray); cdecl;
    [MethodName('centralManager:didRetrieveConnectedPeripherals:')]
    procedure centralManagerDidRetrieveConnectedPeripherals(central: CBCentralManager; peripherals: NSArray); cdecl;
    [MethodName('centralManager:didDiscoverPeripheral:advertisementData:RSSI:')]
    procedure centralManagerDidDiscoverPeripheral(central: CBCentralManager; peripheral: CBPeripheral;
      advertisementData: NSDictionary; RSSI: NSNumber); cdecl;
    [MethodName('centralManager:didConnectPeripheral:')]
    procedure centralManagerDidConnectPeripheral(central: CBCentralManager; peripheral: CBPeripheral); cdecl;
    [MethodName('centralManager:didFailToConnectPeripheral:error:')]
    procedure centralManagerDidFailToConnectPeripheral(central: CBCentralManager; peripheral: CBPeripheral; error: NSError); cdecl;
    [MethodName('centralManager:didDisconnectPeripheral:error:')]
    procedure centralManagerdidDisconnectPeripheral(central: CBCentralManager; peripheral: CBPeripheral; error: NSError); cdecl;
    procedure StartDiscovery(Timeout: Cardinal; const FilterUUIDList: TBluetoothUUIDsList = nil);
    procedure StopDiscovery;
    function ConnectTo(const APeripheral: CBPeripheral): Boolean;
    function CancelConnectionTo(const APeripheral: CBPeripheral): Boolean;
    procedure OnDiscoveryTimeout(Sender: TObject);
    property OnDeviceDiscovered: TDeviceDiscoveredEvent read FOnDeviceDiscovered write FOnDeviceDiscovered;
    property OnDeviceDiscoveryTimeout: TNotifyEvent read FOnDeviceDiscoveryTimeout write FOnDeviceDiscoveryTimeout;
    property OnDeviceConnect: TDeviceConnectionChangeEvent read FOnDeviceConnect write FOnDeviceConnect;
    property OnDeviceDisconnect: TDeviceConnectionChangeEvent read FOnDeviceDisconnect write FOnDeviceDisconnect;
  end;

可见也用到了TInternalBluetoothLEManager和CBCentralManagerDelegate

unit System.Bluetooth;

 {$IFDEF IOS}
  System.Mac.Bluetooth;
{$ELSE}

http://stackoverflow.com/questions/19916513/bluetooth-central-region-monitoring-in-background-and-or-locked-no-display

2016.1.2测试，锁屏后蓝牙保持连接，为断开，就是不发送接受数据了。是不是timer停止了，给外设发送请求数据的命令移动到蓝牙接受事件里，处理完成后发送请求数据命令，而不是在timer里不停的发送，试试这种方式！！！

http://blog.csdn.net/zhuzhihai1988/article/details/30081991

Required background modes

App shares data using CoreBluetooth

App communicates using CoreBluetooth

<key>Required background modes</key>
<array>
<string>App shares data using CoreBluetooth</string>
<string>App communicates using CoreBluetooth</string>
</array>

不选bluetooth central

锁屏后蓝牙未断开连接，解锁后继续通讯，以前的曲线还在，只是锁屏后timer事件不再触发，所以停止运行了。

经过测试验证TApplicationEvent.EnteredBackground事件里， FCurrentDevice.IsConnected连接着呢。

选中bluetooth central

当蓝牙连接成功后，监测数据中，锁屏后，蓝牙断开连接了，android设备可以连接证明蓝牙确实断开了。解锁后弹出连接信息。相当于程序重新运行了，以前的曲线图也没有了。

蓝牙未连接成功，锁屏后解锁没有区别，不会自动连接。

经过测试验证TApplicationEvent.EnteredBackground事件里， FCurrentDevice.IsConnected连接着呢。 

再测试，选中bluetooth central，在EnteredBackground 事件蓝牙保持了吗；不选中，进入EnteredBackground 是否断开了？如果这样就解决问题啦，结果是一样的。 FCurrentDevice.IsConnected就是true。

蓝牙连接，未监测数据，unlock screen it not restore connection.

通过TApplicationEvent事件，EnteredBackground停止计时器，WillBecomeForeground开始计时器，可以连续测试了。唯一的就是处理锁屏后数据接收的问题。以前的问题是从后台切换到前台重新连接蓝牙，现在这个问题好了，平滑切换！！不论选择bluetooth central与否，都好了。

 如果在进入EnteredBackground事件里，不停止timer，不断的执行，就报错了，所以切换回来的时候会重新运行，触发oncreate和onshow事件，导致调用research方法发现设备。！！

connection,sending data,lock screen. debug mode application,see error below.

osx\Macapi.ObjectiveC.pas

class procedure TOCGenericImport<C,T>.Init(O: T; P: Pointer);
var
Imp: TOCImport;
begin// course is here
Imp := TOCImport(TRawVirtualClass.GetInstanceFromInterface(PPointer(@O)^));

{$IFDEF DEBUGUTILS}
TDebugUtils.DebugPrint('oc.instance.init', 'Initing ''%s'' with 0x%x. Old value = 0x%x',
[Imp.ClassName, IntPtr(P), IntPtr(Imp.FID)]);
{$ENDIF}
Imp.FID := P;
end;

 两种可能，一种是代码写的有问题，一种是delphi的bug

DidEnterBackground

测试一下System.Mac.Bluetooth屏蔽此单元，delphi用了此单元的什么组件，屏蔽后BLE控件工程依然可以编译成功！没没用到啊。

TBluetoothLEManager

TBluetoothLE = class(TComponent)
private
protected
FManager: TBluetoothLEManager;

class constructor TBluetoothLEManager.Create;
begin
FBluetoothManagerClass := TPlatformBluetoothLEManager;
end;

 TPlatformBluetoothLEManager就是System.Mac.Bluetooth里的了。最终还是用到了。

http://community.embarcadero.com/index.php/blogs/entry/spelunking-delphi-rtl-new-features-since-xe2

http://community.embarcadero.com/index.php/blogs/entry/bluetooth-le-support-in-rad-studio-xe7

UIBackgroundModes 就是XCode里的 “Required background modes”
Specifies that the app needs to continue running in the background. See UIBackgroundModes for details.