更新MKannotation图像而不闪烁 [英] Updating MKannotation image without flashing

问题描述

我想每5秒在mapview上更新一些注释的图像，但是我不想删除它们并将它们重新添加到地图中，因为这会导致它们闪烁或刷新，（即消失然后重新出现）。我希望它是无缝的。

I want to update the images of some of my annotations on a mapview every 5 seconds, however I dont' want to remove and re-add them to the map as this causes them to 'flash' or refresh, (ie disapear then reappear). I want it to be seamless.

我尝试了以下内容：

//get the current icon
        UserAnnotation *annotation = [self GetUserIconWithDeviceId:deviceId];

        //make a new annotation for it 
        UserAnnotation *newAnnotation = [[UserAnnotation alloc]
                                         initWithCoordinate: userCoordinates
                                         addressDictionary:nil];
        newAnnotation.title = name;
        newAnnotation.userDeviceId = deviceId;
        NSInteger ageIndicator = [[userLocation objectForKey: @"ageIndicator"] integerValue];
        newAnnotation.customImage = [UserIconHelpers imageWithAgeBorder:ageIndicator FromImage: userImage];



        //if its not there, add it 
        if (annotation != nil){
            //move it 

            //update location
            annotation.coordinate = userCoordinates;

            //add new one 
            [self.mapView addAnnotation: newAnnotation];

            //delete old one 
            [self.mapView removeAnnotation: annotation];

        } else {
        //just addd the new one 
            [self.mapView addAnnotation: newAnnotation]; 
        }

如果我在顶部添加了新图标我可以删除旧的图标，但这仍然导致闪烁。

as a thought that if I added the new icon on top I could then remove the old icon, but this still caused the flashing.

有没有人有任何想法？

Has anyone got any ideas?

推荐答案

如果注释不是nil，而不是添加和删除，请尝试：

In the case where the annotation is not nil, instead of adding and removing, try this:

annotation.customImage = ... //the new image
MKAnnotationView *av = [self.mapView viewForAnnotation:annotation];
av.image = annotation.customImage;

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