Howto call initWithDelegate and CBCentralManagerOptionShowPowerAlertKey

[Rollo62 536]

Hi there,

 

I wanted to call the Bluetooth initWithDictionary and its option CBCentralManagerOptionShowPowerAlertKey;

There is little information out there howto create the options for this call in the right way.

  CBCentralManager = interface(NSObject)
  ['{587D1855-5B53-43DA-91AF-AF9D93FFDB9F}']
    ...
    function initWithDelegate(delegate: id; queue: dispatch_queue_t; options: NSDictionary): id; cdecl; overload;

In XCode that looks quite straightforward, but what about Fmx ?

let opts = [CBCentralManagerOptionShowPowerAlertKey: false]
let manager = CBCentralManager(delegate: self, 
                               queue: nil, 
                               options: opts)

 

Info's like this doesn't help much

http://codeverge.com/embarcadero.delphi.firemonkey/help-rewrite-objective-c-proced/1046099

 

Using NSUserDefaults to access the info list properties seems not to work, returning nil.

But is NSUserDefaults the right place to look for those keys ?

 

var
    LDefaults: NSUserDefaults; 
    LDict: NSDictionary;       

begin
  LDefaults := TNSUserDefaults.Wrap(TNSUserDefaults.OCClass.standardUserDefaults);
  LDict     := LDefaults.dictionaryForKey( CBCentralManagerOptionShowPowerAlertKey ); // ! This (LDict) is nil

if Assigned(lDict) then
      FCentralManager := TCBCentralManager.Wrap(
          TCBCentralManager.Alloc.initWithDelegate(
              GetObjectID,
              0,
              LDict  
              ))

I used this function to get the key constant

function CBCentralManagerOptionShowPowerAlertKey : NSString;
begin
  Result := CocoaNSStringConst(libCoreBluetooth, 'CBCentralManagerOptionShowPowerAlertKey');
end;

Other ways to construct this NSDictionary look to ugly to be true:

  LDict     := TNSDictionary.Wrap(
                   TNSDictionary.OCClass.dictionaryWithObjectsAndKeys(
                      <<This is Pointer to object a nil-terminated list>>));

 

Maybe somebody can help with some useful hints, to find the right way to access such system options  ?

 

[Dave Nottage 557]

 

13 hours ago, Rollo62 said:

Other ways to construct this NSDictionary look to ugly to be true:

They're ugly, but they are true. In your case however you should need only use dictionaryWithObject (since there is only one value), thus:

var
  LDict: NSDictionary;
  LBooleanValue: Pointer;
begin
  LBooleanValue := TNSNumber.OCClass.numberWithBool(True);
  LDict := TNSDictionary.Wrap(TNSDictionary.OCClass.dictionaryWithObject(LBooleanValue, NSObjectToID(CBCentralManagerOptionShowPowerAlertKey)));
end;

 

[Rollo62 536]

@Dave Nottage

Thanks, I will check that.

Never know when to use what and why excactly when it comes to iOS objects

 

Edited April 22, 2020 by Rollo62

[Rollo62 536]

Yes it works with that configuration, the LDict is assigned,

and even better, the Bluetooth alert appears.

 

Thanks again Dave.