ios - 将对象解析为 AnnonationPoints

Question

我试图在 MKMapView 中将一组解析对象显示为 Annonations。这似乎可行，问题是交换了对象图像，这是随机的吗？我已经开始创建 MKPointAnnotation 的子类以保存图像。图片怎么调换了？

自定义 MKPointAnnonation 类

类 AnnonationClass:MKPointAnnotation {

var itemId: NSString?
var itemImage: PFFile?
var itemdescription: NSString?

获取解析对象并使用 setGeoPoint 方法添加它们

override func objectsDidLoad(error: NSError!) {
    super.objectsDidLoad(error)
    if error == nil {

        self.pointMapView?.removeAnnotations(pointMapView?.annotations)

        for object in objects {

            var theObject = object as PFObject

            let dateFormatter = NSDateFormatter()
            dateFormatter.dateFormat = "yyyy-MM-dd" // superset of OP's format
            let str = dateFormatter.stringFromDate(object.createdAt)


            self.setGeoPoint(theObject.objectForKey("location") as PFGeoPoint, titleString: theObject.objectForKey("title") as NSString, imageFile: theObject.objectForKey("image") as PFFile, theId: theObject.objectId as NSString, descString: theObject.objectForKey("description") as NSString, dateString: str)

        }



    }
}

在itemImage中设置坐标、标题并保存imageFile

func setGeoPoint(geoPoint:PFGeoPoint, titleString:NSString, imageFile:PFFile, theId:NSString, descString:NSString, dateString:NSString) {

    var coordinate = CLLocationCoordinate2DMake(geoPoint.latitude, geoPoint.longitude) as CLLocationCoordinate2D
    var pinView:AnnonationClass = AnnonationClass()


            pinView.itemImage = imageFile
            pinView.setCoordinate(coordinate)
            pinView.title = titleString
            pinView.subtitle = dateString

            self.pointMapView!.addAnnotation(pinView)








}

创建图像并设置它

func mapView(mapView: MKMapView!, viewForAnnotation annotation: AnnonationClass!) -> MKAnnotationView! {



    let reuseId = "pin"

    var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId) as? MKPinAnnotationView
    if pinView == nil {
        pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
        pinView!.canShowCallout = true
        pinView!.animatesDrop = true
        pinView!.pinColor = .Purple



        var leftImage: PFImageView = PFImageView(frame: CGRectMake(0, 0, 44, 44))
        leftImage.file = annotation.itemImage
        leftImage.loadInBackground()
        pinView!.leftCalloutAccessoryView = leftImage

    }
    else {
        pinView!.annotation = annotation
    }

    return pinView
}

Answer 1

在您的 viewForAnnotation 中，当 pinView != nil 时，即重复使用 View 时，很可能是从上次使用该 View 时设置的图像。我认为这类似于在表格 View 单元格上设置复选标记，而不是使用数据源来正确设置单元格内容的属性。

无论 pinView 是否被重用，都尝试设置 ImageView 。

func mapView(mapView: MKMapView!, viewForAnnotation annotation: AnnonationClass!) -> MKAnnotationView! {



let reuseId = "pin"

var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId) as? MKPinAnnotationView
if pinView == nil {
    pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
    pinView!.canShowCallout = true
    pinView!.animatesDrop = true
    pinView!.pinColor = .Purple

}
else {
    pinView!.annotation = annotation
}

var leftImage: PFImageView = PFImageView(frame: CGRectMake(0, 0, 44, 44))
leftImage.file = annotation.itemImage
leftImage.loadInBackground()
pinView!.leftCalloutAccessoryView = leftImage

return pinView