ios - 自定义 CALayer 不会响应选择器

Question

我需要一个自定义层（由新变量和方法扩展）并如下所示。问题是该层不会响应我的方法：

-[CALayer drawHourCircleWithDayLightStart:dayLightEnd:animated:]：无法识别的选择器发送到实例 0x6a6d560**

似乎我的自定义图层没有被视为 HourCircleLayer，而是被视为 CALayer。但我必须在这里改变吗？

我的实现如下所示：

@interface HourCircleLayer : CALayer
   @property (strong) UIColor *dayColor;   // default yellowColor
   @property (strong) UIColor *nightColor; // default blueColor
   + (id)layer;
   - (void)drawHourCircleWithDayLightStart:(NSDate *)startDate dayLightEnd:(NSDate *)endDate animated:(BOOL)animated;
@end

@implementation HourCircleLayer
  + (id)layer
  {
     id layer = [CALayer layer];
     [layer setValue:[UIColor yellowColor] forKey:kDayPortionColorKey];
     [layer setValue:[UIColor blueColor]   forKey:kNightPortionColorKey];

     return layer;
  }

  - (void)drawHourCircleWithDayLightStart:(NSDate *)startDate dayLightEnd:(NSDate *)endDate animated:(BOOL)animated
  {
     self.withAnimation = animated;
     [self setDayLightStart:[self hourAngleForDate:startDate]];
     [self setDayLightEnd:[self hourAngleForDate:endDate]];
  }

@end

Answer 1

这是因为你初始化CALayer了 ，而不是你的HourCircleLayer. 在您的 + (id)layer方法更改中：

id layer = [CALayer layer];

到

HourCircleLayer layer = [[HourCircleLayer alloc] init];
...

return [layer autorelease]; //Use autorelease if not using ARC

Answer 2

第二种方法不是类方法，所以你应该这样做

HourCircleLayer *hourCircleLayer = [[HourCircleLayer alloc] init];
[hourCircleLayer drawHourCircleWithDayLightStart:dayLightEnd:animated:];