是否可以将 UIGestureRecognizer 附加到子类 UIImageView？

Question

在将 UIPanGestureRecognizer 附加到子类 UIImageView 时，出现“无法识别的选择器发送到实例”消息的崩溃。我需要继承 UIImageView 来保存自定义属性，所以我只是这样做并添加了这些属性。我已经直接在 UIImageView 上测试了平移，它按预期工作。但是，它不适用于子类 UIImageView。下面是代码（self.myImageView 是 UIImageView 的子类，self.defaultImageView 是 UIImageView ）：

- (void)viewDidLoad
{
  [super viewDidLoad];

  UIPanGestureRecognizer * pgr = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(moveCustomImageView:)];
  [self.myImageView addGestureRecognizer:pgr]; //nop, getting error during runtime on start panning
  [pgr release];
  ...
  pgr = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(moveUIImageView:)];
  [self.defaultImageView addGestureRecognizer:pgr]; //yep, that works
  [pgr release];

处理程序方法声明具有相同的结构

-(void)moveUIImageView:(UIPanGestureRecognizer *)pan{
  ...
}

-(void)moveCustomImageView:(UIPanGestureRecognizer *)pan{
  ...
}

Answer 1

UIImageView 默认将setUserInteractionEnabled 标志设置为NO 和setMultipleTouchEnabled 设置为NO。您是否尝试将这些标志转为YES？

你可以这样改——

[self.myImageView setMultipleTouchEnabled:YES];
[self.myImageView setUserInteractionEnabled:YES];