CODEWITHSUNDEEP
iosswiftuiimagemkmapview
harry lakins
harry lakins

Reputation: 843

Why is my UIImage not set propely in Swift?

I am using MKMapSnapShotter, but when I set a break point on return finalImage , I can see the value is just an empty ObjectiveC.NSObject, instead of UIImage.

 func getIMG() -> UIImage{
        var finalImage =  UIImage();
        let imageOptions = MKMapSnapshotOptions();
        imageOptions.region = mapView.region;
        imageOptions.size = mapView.frame.size;
        imageOptions.showsBuildings = true;

        let imgMap = MKMapSnapshotter(options: imageOptions);
        imgMap.start(completionHandler: { (imageObj: MKMapSnapshot?, Error) -> Void in
            if(Error != nil){
                print("\(Error)");
            }else{
                finalImage = imageObj!.image;
            }

        });

        return finalImage;

    }

My map loads correctly, etc, so the problem must be here. Also, what is the quickest and easiest way to view the image for testing purposes ? (I don't want to have to design a imageView, etc just to see the image it produces).

Cheers

UPDATE:

func getIMG( completion: @escaping (UIImage)->() ){
        var finalImage =  UIImage();
        let imageOptions = MKMapSnapshotOptions();
        imageOptions.region = mapView.region;
        imageOptions.size = mapView.frame.size;
        imageOptions.showsBuildings = true;

        let imgMap = MKMapSnapshotter(options: imageOptions);
        imgMap.start(completionHandler: { (imageObj: MKMapSnapshot?, Error) -> Void in
            if(Error != nil){
                print("\(Error)");
            }else{
                finalImage = imageObj!.image;
            }
            completion(finalImage);

        });

    }

-

  map.getMapAsIMG{ (image) in
        print(image);
    };

Note: compiler needed me to use @escape ...

Upvotes: 0

Views: 88

Answers (1)

Nirav D
Nirav D

Reputation: 72410

You can not return from function that use closure, so you also use closure with your function.

func getIMG(completion: (UIImage) -> ()) {

    var finalImage =  UIImage();
    let imageOptions = MKMapSnapshotOptions();
    imageOptions.region = mapView.region;
    imageOptions.size = mapView.frame.size;
    imageOptions.showsBuildings = true;

    let imgMap = MKMapSnapshotter(options: imageOptions);
    imgMap.start(completionHandler: { (imageObj: MKMapSnapshot?, error) -> Void in
        if(error != nil){
            print("\(Error)");
        }else{
            finalImage = imageObj!.image;
        }
        completion(finalImage)
    });
}

Now call this function like this.

self.getIMG { (image) in
    //Access the image object
}

Upvotes: 3

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