Check Bluetooth state on iOS

Unit1.pas

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,
  Macapi.ObjectiveC, Macapi.Bluetooth,
  iOSapi.Foundation, iOSapi.CocoaTypes;

type
  CBConnectionEvent = NSInteger;

  CBCentralManagerDelegate = interface(IObjectiveC)
    ['{3A116076-D6AB-4437-BD82-0326D057DBC5}']
    [MethodName('centralManager:connectionEventDidOccur:forPeripheral:')]
    procedure centralManagerConnectionEventDidOccur(central: CBCentralManager; connectionEventDidOccur: CBConnectionEvent; forPeripheral: CBPeripheral); cdecl;
    [MethodName('centralManager:didConnectPeripheral:')]
    procedure centralManagerDidConnectPeripheral(central: CBCentralManager; didConnectPeripheral: CBPeripheral); cdecl;
    [MethodName('centralManager:didDisconnectPeripheral:error:')]
    procedure centralManagerDidDisconnectPeripheral(central: CBCentralManager; didDisconnectPeripheral: CBPeripheral; error: NSError); cdecl;
    [MethodName('centralManager:didDiscoverPeripheral:advertisementData:RSSI:')]
    procedure centralManagerDidDiscoverPeripheral(central: CBCentralManager; didDiscoverPeripheral: CBPeripheral; advertisementData: NSDictionary; RSSI: NSNumber); cdecl;
    [MethodName('centralManager:didFailToConnectPeripheral:error:')]
    procedure centralManagerDidFailToConnectPeripheral(central: CBCentralManager; didFailToConnectPeripheral: CBPeripheral; error: NSError); cdecl;
    [MethodName('centralManager:didUpdateANCSAuthorizationForPeripheral:')]
    procedure centralManagerDidUpdateANCSAuthorizationForPeripheral(central: CBCentralManager; didUpdateANCSAuthorizationForPeripheral: CBPeripheral); cdecl;
    procedure centralManagerDidUpdateState(central: CBCentralManager); cdecl;
    [MethodName('centralManager:willRestoreState:')]
    procedure centralManagerWillRestoreState(central: CBCentralManager; willRestoreState: NSDictionary); cdecl;
  end;

  TCBCentralManagerDelegate = class(TOCLocal, CBCentralManagerDelegate)
  public
    { CBCentralManagerDelegate }
    [MethodName('centralManager:connectionEventDidOccur:forPeripheral:')]
    procedure centralManagerConnectionEventDidOccur(central: CBCentralManager; connectionEventDidOccur: CBConnectionEvent;
      forPeripheral: CBPeripheral); cdecl;
    [MethodName('centralManager:didConnectPeripheral:')]
    procedure centralManagerDidConnectPeripheral(central: CBCentralManager; didConnectPeripheral: CBPeripheral); cdecl;
    [MethodName('centralManager:didDisconnectPeripheral:error:')]
    procedure centralManagerDidDisconnectPeripheral(central: CBCentralManager; didDisconnectPeripheral: CBPeripheral; error: NSError); cdecl;
    [MethodName('centralManager:didDiscoverPeripheral:advertisementData:RSSI:')]
    procedure centralManagerDidDiscoverPeripheral(central: CBCentralManager; didDiscoverPeripheral: CBPeripheral; advertisementData: NSDictionary;
      RSSI: NSNumber); cdecl;
    [MethodName('centralManager:didFailToConnectPeripheral:error:')]
    procedure centralManagerDidFailToConnectPeripheral(central: CBCentralManager; didFailToConnectPeripheral: CBPeripheral; error: NSError); cdecl;
    [MethodName('centralManager:didUpdateANCSAuthorizationForPeripheral:')]
    procedure centralManagerDidUpdateANCSAuthorizationForPeripheral(central: CBCentralManager;
      didUpdateANCSAuthorizationForPeripheral: CBPeripheral); cdecl;
    procedure centralManagerDidUpdateState(central: CBCentralManager); cdecl;
    [MethodName('centralManager:willRestoreState:')]
    procedure centralManagerWillRestoreState(central: CBCentralManager; willRestoreState: NSDictionary); cdecl;
  end;

  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    FCentralManager: CBCentralManager;
    FCentralManagerDelegate: TCBCentralManagerDelegate;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.fmx}

{ TCBCentralManagerDelegate }

procedure TCBCentralManagerDelegate.centralManagerConnectionEventDidOccur(central: CBCentralManager; connectionEventDidOccur: CBConnectionEvent;
  forPeripheral: CBPeripheral);
begin

end;

procedure TCBCentralManagerDelegate.centralManagerDidConnectPeripheral(central: CBCentralManager; didConnectPeripheral: CBPeripheral);
begin

end;

procedure TCBCentralManagerDelegate.centralManagerDidDisconnectPeripheral(central: CBCentralManager; didDisconnectPeripheral: CBPeripheral;
  error: NSError);
begin

end;

procedure TCBCentralManagerDelegate.centralManagerDidDiscoverPeripheral(central: CBCentralManager; didDiscoverPeripheral: CBPeripheral;
  advertisementData: NSDictionary; RSSI: NSNumber);
begin

end;

procedure TCBCentralManagerDelegate.centralManagerDidFailToConnectPeripheral(central: CBCentralManager; didFailToConnectPeripheral: CBPeripheral;
  error: NSError);
begin

end;

procedure TCBCentralManagerDelegate.centralManagerDidUpdateANCSAuthorizationForPeripheral(central: CBCentralManager;
  didUpdateANCSAuthorizationForPeripheral: CBPeripheral);
begin

end;

procedure TCBCentralManagerDelegate.centralManagerDidUpdateState(central: CBCentralManager);
begin
  case central.state of
     CBManagerStateUnknown: ShowMessage('unknown');
     CBManagerStateResetting: ShowMessage('resetting');
     CBManagerStateUnsupported: ShowMessage('unsupported');
     CBManagerStateUnauthorized: ShowMessage('unauthorized');
     CBManagerStatePoweredOff: ShowMessage('off');
     CBManagerStatePoweredOn: ShowMessage('on');
  end;
end;

procedure TCBCentralManagerDelegate.centralManagerWillRestoreState(central: CBCentralManager; willRestoreState: NSDictionary);
begin

end;

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
begin
  FCentralManagerDelegate := TCBCentralManagerDelegate.Create;
  FCentralManager := TCBCentralManager.Wrap(TCBCentralManager.Alloc.initWithDelegate(FCentralManagerDelegate.GetObjectID, 0));
end;

end.

CBCentralManagerDelegate has been redeclared here because the one in the Delphi source is either wrong and/or out of date.