随着用户的移动，我想在其旧位置上绘制另一个Mkannotation，这与Objective-C中的当前注释不同

Question

当用户移动时，我想在其旧位置上绘制另一个Mkannotation，这与Objective-C中的当前注释不同

我写了代码

-(void)plotDotted:(double)latitude :(double)longitude
{
    _busOldAnnotation.coordinate = CLLocationCoordinate2DMake(latitude, longitude);
    [self.sampleMap addAnnotation:_busOldAnnotation];
}
-(void)plotPoint:(double)latitude :(double)longitude 
{
    _busAnnotation.coordinate = CLLocationCoordinate2DMake(latitude, longitude);
    [self.sampleMap addAnnotation:_busAnnotation]; 
}

注释委托

-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
    static NSString *Identifier = @"driverView";

        MKAnnotationView* myAnnotation = [self.sampleMap dequeueReusableAnnotationViewWithIdentifier:Identifier];
        if (myAnnotation == nil)
        {
            myAnnotation = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:Identifier];
            //myAnnotation.enabled = YES;
        }

    CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(_latituDouble, _longitudeDouble);
    if (coordinate.latitude == _latituDouble && coordinate.longitude == _longitudeDouble)
    {
        myAnnotation.image = [UIImage imageNamed:@"bus_icon.png"];
    }
    else if (_busOldAnnotation)
    {
        myAnnotation.image = [UIImage imageNamed:@"blue_dot.png"];
    }

    return myAnnotation;
}
Called Functions
                                    //1. Remove
                                    [self removeAnnotation];
                                    //3. Add new
                                    [self plotPoint:latitudeDouble :longitudeDouble];
                                    //2. Add Old
                                    [self plotDotted:_latituDouble :_longitudeDouble];
                                    //4. Assign that coordinate to global
                                    _latituDouble = latitudeDouble;
                                    _longitudeDouble = longitudeDouble;
                                    [self.sampleMap reloadInputViews];

一切正常，用户正在我的地图上移动，删除以前的位置，但是在该用户移动

Answer 1

使用此功能，看看它是否有效

 -(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
 CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(_latituDouble, _longitudeDouble);
if (coordinate.latitude == _latituDouble && coordinate.longitude == _longitudeDouble)
{
        static NSString *Identifier1 = @"driverView";
    MKAnnotationView* myAnnotation = [self.sampleMap dequeueReusableAnnotationViewWithIdentifier:Identifier1];
    if (myAnnotation == nil)
    {
        myAnnotation = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:Identifier];
        //myAnnotation.enabled = YES;
    }
    myAnnotation.image = [UIImage imageNamed:@"bus_icon.png"];
    return myAnnotation;

}
else if (_busOldAnnotation)
{
        static NSString *Identifier2 = @"driverView2";
    MKAnnotationView* myAnnotation = [self.sampleMap dequeueReusableAnnotationViewWithIdentifier:Identifier2];
    if (myAnnotation == nil)
    {
        myAnnotation = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:Identifier];
        //myAnnotation.enabled = YES;
    }
    myAnnotation.image = [UIImage imageNamed:@"blue_dot.png"];
    return myAnnotation;

}
 return nil;
}