ios - I have stopped captureSession but Scanner is yet working. How to resolve this bug? - 


func scan(){     capturesession = avcapturesession()      let videoinput: avcapturedeviceinput     let videocapturedevice = avcapturedevice.defaultdevice(withmediatype: avmediatypevideo)     let metadataoutput = avcapturemetadataoutput()      {         videoinput = try avcapturedeviceinput(device: videocapturedevice)     } catch {         return     }      if (capturesession.canaddinput(videoinput)) {         capturesession.addinput(videoinput)     } else {         failed()         return     }      if (capturesession.canaddoutput(metadataoutput)) {         capturesession.addoutput(metadataoutput)          metadataoutput.setmetadataobjectsdelegate(self, queue: dispatchqueue.main)         metadataoutput.metadataobjecttypes = [avmetadataobjecttypeean8code, avmetadataobjecttypeean13code, avmetadataobjecttypepdf417code, avmetadataobjecttypecode128code, avmetadataobjecttypeitf14code, avmetadataobjecttypecode39code]     } else {         failed()         return     }     var caplayer = self.previewlayer     caplayer = avcapturevideopreviewlayer(session: capturesession);     caplayer?.videogravity = avlayervideogravityresizeaspectfill     caplayer?.frame = self.cameraview.layer.bounds     self.cameraview.layer.addsublayer(caplayer!)     capturesession.startrunning() }  func failed() {     let ac = uialertcontroller(title: "scanning not supported", message: "your device not support scanning code item. please use device camera.", preferredstyle: .alert)     ac.addaction(uialertaction(title: "ok", style: .default, handler: nil))     present(ac, animated: true, completion: nil)     capturesession = nil } func captureoutput(_ captureoutput: avcaptureoutput!, didoutputmetadataobjects metadataobjects: [any]!, connection: avcaptureconnection!) {     capturesession.stoprunning()      if let metadataobject: anyobject = metadataobjects.first anyobject? {         let readableobject = metadataobject as! avmetadatamachinereadablecodeobject;         audioservicesplaysystemsound(systemsoundid(ksystemsoundid_vibrate))         foundcode(readableobject.stringvalue)     }     if (capturesession?.isrunning == true) {         capturesession.stoprunning()         capturesession = nil     }      dismiss(animated: true, completion: nil) } func foundcode(_ code: string) {     capturesession.stoprunning()     storeid = (userdefaults.standard.value(forkey: defaultskey.storeid.rawvalue) as? int)!     scannedcode = ("\(code)")     if (capturesession?.isrunning == true) {         capturesession.stoprunning()         capturesession = nil     }     apicall() }

structure of app: triggering scan on click of button after successful api call. have stopped capture session once barcode found continuously scanning , sendung multiple api calls.

suggest how stop camera scanning without being triggered.

i guess @ point still stops , had same issue it. problem capture session uses queue, , when manages scan something, still able scan several times, until code stops it. why receive several delegate callbacks.

you can have 2 options here:

  1. make delegate nil when first receive callback , set again when want start.(though not sure work)
  2. as did... introduce bool flag filter unwanted callbacks in delegate.

Comments

Post a Comment

Popular posts from this blog

What is happening when Matlab is starting a "parallel pool"? -

running parallel cpu processes in matlab starts command parpool() according documentation , function: [creates] special job on pool of workers, , [connects] matlab client parallel pool. this function takes bit of time execute, on order of 30 seconds. in other multi-cpu paradigms openmp, parallel execution seems totally transparent -- i've never noticed behavior analogous matlab (granted i'm not experienced parallel programming). so, happening between time parpool() called , when finishes executing? takes long? parallel computing toolbox enables run matlab code in parallel using several different paradigms (e.g. jobs , tasks, parfor , spmd , parfeval , batch processing), , run either locally (parallelised across cores in local machine) or remotely (parallelised across machines in cluster - either 1 own, or 1 in cloud). in of these cases, code run on matlab workers , copies of matlab without interactive desktop. if you're intending run on remo...
Read more

php - Cannot override Laravel Spark authentication with own implementation -

during login process of laravel spark need request token of remote api. api stores exact same users , passwords laravel spark application. therefore need username , non hashed password of user during authentication process. i thought overriding authenticated method solution problem. in routes/web.php override post /login endpoint , pointing endpoint own logincontroller: <?php namespace app\http\controllers\auth; use illuminate\support\facades\log; use illuminate\http\request; use laravel\spark\http\controllers\auth\logincontroller sparklogincontroller; class logincontroller extends sparklogincontroller { /** * create new login controller instance. * * @return void */ public function __construct() { parent::__construct(); } /** * handle successful authentication attempt. * * @param request $request * @param \illuminate\contracts\auth\authenticatable $user * @return response */ public fu...
Read more

Qt QGraphicsScene is not accessable from QGraphicsView (on Qt 5.6.1) -

i new qt. trying catch mouse press , release in qgraphicsview area , draw line. this, extended qgraphicsview , called myqgraphicsview . seems scene not attached since added " hello world " , never appears in view. here code extended class: class myqgraphicsview : public qgraphicsview { q_object public: myqgraphicsview(qgraphicsscene *scene, qwidget *parent = q_nullptr) : qgraphicsview(scene,parent){ // qgraphicsview::qgraphicsview(scene,parent); } qpoint *pointptr, *startpos,*endpos; qgraphicsview *cv;//maa qgraphicsscene *c; qgraphicsscene *sceneptr; // maa protected: void paintevent(qpaintevent *event) { show(); } void mousepressevent(qmouseevent *event) { // pos wrt widget. global wer global screen qdebug()<<" mouse pressed @ "<<qwidget::mapfromglobal(event->globalpos()); //globalx(); startpos = new qpoint; startpos->setx(qwidget::mapfromglobal(event->globalpos()).x()); startpos->sety(qw...
Read more