我有MKMapView的实例，并希望使用自定义注释图标，而不是MKPinAnnotationView提供的标准图钉图标。所以，我设置了一个名为CustomMapAnnotation的MKAnnotationView的子类，并覆盖-(void)drawRect:来绘制CGImage。这很有效。
当我尝试复制MKPinAnnotationView提供的.animatesDrop功能时出现问题;当注释被添加到MKMapView实例时，我希望我的图标能够逐渐显示，从上到下以及从左到右顺序显示。
这是 - （void）drawRect：用于CustomMapAnnotation，当你只绘制UIImage时（第二行就是这样），它可以工作：
- (void)drawRect:(CGRect)rect {
[super drawRect:rect];
[((Incident *)self.annotation).smallIcon drawInRect:rect];
if (newAnnotation) {
[self animateDrop];
newAnnotation = NO;
}
}
添加animateDrop方法时出现问题：
-(void)animateDrop {
CGContextRef myContext = UIGraphicsGetCurrentContext();
CGPoint finalPos = self.center;
CGPoint startPos = CGPointMake(self.center.x, self.center.y-480.0);
self.layer.position = startPos;
CABasicAnimation *theAnimation;
theAnimation=[CABasicAnimation animationWithKeyPath:@"position"];
theAnimation.fromValue=[NSValue valueWithCGPoint:startPos];
theAnimation.toValue=[NSValue valueWithCGPoint:finalPos];
theAnimation.removedOnCompletion = NO;
theAnimation.fillMode = kCAFillModeForwards;
theAnimation.delegate = self;
theAnimation.beginTime = 5.0 * (self.center.x/320.0);
theAnimation.duration = 1.0;
[self.layer addAnimation:theAnimation forKey:@""];
}
它只是不起作用，可能有很多原因。我现在不会进入所有这些。我想知道的主要问题是这种方法是否合理，或者我是否应该尝试完全不同的方法。
我还尝试将整个事件打包成动画事务，以便beginTime参数可以实际工作;这似乎根本没有做任何事情。我不知道这是因为我错过了一些关键点，还是因为MapKit以某种方式破坏了我的动画。
// Does nothing
[CATransaction begin];
[map addAnnotations:list];
[CATransaction commit];
如果有人对像这样的动画MKMapAnnotations有任何经验，我会喜欢一些提示，否则如果你能提供有关该方法的CAAnimation建议，那也会很棒。
答案 0 :(得分：58)
Paul Shapiro的代码存在的一个问题是，当您在用户正在查看的位置下方添加注释时，它不会处理。这些注释会在下降之前浮动在半空中，因为它们会被移动到用户的可见地图中。
另一个是它也会丢弃用户位置蓝点。使用下面的代码，您可以在屏幕外处理用户位置和大量地图注释。我也加了一个漂亮的反弹;）
- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views {
MKAnnotationView *aV;
for (aV in views) {
// Don't pin drop if annotation is user location
if ([aV.annotation isKindOfClass:[MKUserLocation class]]) {
continue;
}
// Check if current annotation is inside visible map rect, else go to next one
MKMapPoint point = MKMapPointForCoordinate(aV.annotation.coordinate);
if (!MKMapRectContainsPoint(self.mapView.visibleMapRect, point)) {
continue;
}
CGRect endFrame = aV.frame;
// Move annotation out of view
aV.frame = CGRectMake(aV.frame.origin.x, aV.frame.origin.y - self.view.frame.size.height, aV.frame.size.width, aV.frame.size.height);
// Animate drop
[UIView animateWithDuration:0.5 delay:0.04*[views indexOfObject:aV] options:UIViewAnimationCurveLinear animations:^{
aV.frame = endFrame;
// Animate squash
}completion:^(BOOL finished){
if (finished) {
[UIView animateWithDuration:0.05 animations:^{
aV.transform = CGAffineTransformMakeScale(1.0, 0.8);
}completion:^(BOOL finished){
[UIView animateWithDuration:0.1 animations:^{
aV.transform = CGAffineTransformIdentity;
}];
}];
}
}];
}
}
答案 1 :(得分：52)
首先，您需要让视图控制器实现MKMapViewDelegate（如果尚未实现）。
然后，实现此方法：
- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views {
MKAnnotationView *aV;
for (aV in views) {
CGRect endFrame = aV.frame;
aV.frame = CGRectMake(aV.frame.origin.x, aV.frame.origin.y - 230.0, aV.frame.size.width, aV.frame.size.height);
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.45];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
[aV setFrame:endFrame];
[UIView commitAnimations];
}
}
将注释添加到MapView中，添加注释后，将调用此委托方法，并在添加引脚时从上到下为引脚设置动画。
定时和定位的值可以稍微改变，但我已经调整它以使它看起来最好/最接近传统的下降（据我测试过）。希望这有帮助！
答案 2 :(得分：12)
或者，如果您正在创建MKAnnotationView子类，则可以使用didMoveToSuperview来触发动画。以下是以轻微的“挤压”效果结束的下降
#define kDropCompressAmount 0.1
@implementation MyAnnotationViewSubclass
...
- (void)didMoveToSuperview {
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
animation.duration = 0.4;
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DMakeTranslation(0, -400, 0)];
animation.toValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
CABasicAnimation *animation2 = [CABasicAnimation animationWithKeyPath:@"transform"];
animation2.duration = 0.10;
animation2.beginTime = animation.duration;
animation2.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
animation2.toValue = [NSValue valueWithCATransform3D:CATransform3DScale(CATransform3DMakeTranslation(0, self.layer.frame.size.height*kDropCompressAmount, 0), 1.0, 1.0-kDropCompressAmount, 1.0)];
animation2.fillMode = kCAFillModeForwards;
CABasicAnimation *animation3 = [CABasicAnimation animationWithKeyPath:@"transform"];
animation3.duration = 0.15;
animation3.beginTime = animation.duration+animation2.duration;
animation3.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
animation3.toValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
animation3.fillMode = kCAFillModeForwards;
CAAnimationGroup *group = [CAAnimationGroup animation];
group.animations = [NSArray arrayWithObjects:animation, animation2, animation3, nil];
group.duration = animation.duration+animation2.duration+animation3.duration;
group.fillMode = kCAFillModeForwards;
[self.layer addAnimation:group forKey:nil];
}
答案 3 :(得分：5)
对于Michael Tyson的回复（我无法在任何地方评论），我建议在didMoveToSuperview中插入以下代码以正确重用MKAnnotationView，以便再次执行动画，然后模拟注释的顺序添加
使用分隔线和乘数来获得不同的视觉效果......
- (void)didMoveToSuperview {
//necessary so it doesn't add another animation when moved to superview = nil
//and to remove the previous animations if they were not finished!
if (!self.superview) {
[self.layer removeAllAnimations];
return;
}
float xOriginDivider = 20.;
float pos = 0;
UIView *mySuperview = self.superview;
while (mySuperview && ![mySuperview isKindOfClass:[MKMapView class]])
mySuperview = mySuperview.superview;
if ([mySuperview isKindOfClass:[MKMapView class]])
//given the position in the array
// pos = [((MKMapView *) mySuperview).annotations indexOfObject:self.annotation];
// left to right sequence;
pos = [((MKMapView *) mySuperview) convertCoordinate:self.annotation.coordinate toPointToView:mySuperview].x / xOriginDivider;
float yOffsetMultiplier = 20.;
float timeOffsetMultiplier = 0.05;
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
animation.duration = 0.4 + timeOffsetMultiplier * pos;
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DMakeTranslation(0, -400 - yOffsetMultiplier * pos, 0)];
animation.toValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
// rest of animation group...
}
答案 4 :(得分：0)
我认为更好的选择是将'animatesDrop'设置为YES。它是MKPinAnnotationView的属性。