自定义annotation的动画

gistfile1.m

// 从上往下落的动作 (MKMapViewDelegate method)
- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views
{
    CGRect visibleRect = [mapView annotationVisibleRect];
    for (MKAnnotationView *view in views) {
        CGRect endFrame = view.frame;
        CGRect startFrame = endFrame;
        startFrame.origin.y = visibleRect.origin.y - startFrame.size.height;
        view.frame = startFrame;
        [UIView beginAnimations:@"drop" context:NULL];
        [UIView setAnimationDuration:0.5f];
        view.frame = endFrame;
        [UIView commitAnimations];
    }
}

// 拖拽大头针时抬起动作 (在继承MKAnnotationView的子类中重新此方法)
- (void)setDragState:(MKAnnotationViewDragState)newDragState animated:(BOOL)animated
{
    if (newDragState == MKAnnotationViewDragStateStarting)
    {
        CGPoint endPoint = CGPointMake(self.center.x,self.center.y-20);
        [UIView animateWithDuration:0.2
                         animations:^{ self.center = endPoint; }
                         completion:^(BOOL finished)
         { self.dragState = MKAnnotationViewDragStateDragging; }];
    }
    else if (newDragState == MKAnnotationViewDragStateEnding)
    {
        CGPoint endPoint = CGPointMake(self.center.x,self.center.y+20);
        [UIView animateWithDuration:0.2
                         animations:^{ self.center = endPoint; }
                         completion:^(BOOL finished)
         { self.dragState = MKAnnotationViewDragStateNone; }];
    }
    else if (newDragState == MKAnnotationViewDragStateCanceling)
    {
        CGPoint endPoint = CGPointMake(self.center.x,self.center.y+20);
        [UIView animateWithDuration:0.2
                         animations:^{ self.center = endPoint; }
                         completion:^(BOOL finished)
         { self.dragState = MKAnnotationViewDragStateNone; }];
    }
}

// http://stackoverflow.com/questions/3677166/subclassing-mkannotationview-and-overriding-setdragstate