我一直在试图弄清楚如何将触摸从 UIScrollView 转发到它的超级视图。原因是某种光标跟随触摸。无论如何,滚动视图都填充了 UIButtons。我转发触摸的代码是在滚动视图子类中使用委托:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
[super touchesBegan:touches withEvent:event];
if ([[self tfDelegate]respondsToSelector:@selector(tfDelegateBegan:)]) {
[[self tfDelegate]tfDelegateBegan:[touches anyObject]];
}
NSLog(@"touches began");
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
[super touchesMoved:touches withEvent:event];
if ([[self tfDelegate]respondsToSelector:@selector(tfDelegateMoved:)]) {
[[self tfDelegate]tfDelegateMoved:[touches anyObject]];
}
NSLog(@"touches moved");
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
[super touchesEnded:touches withEvent:event];
if ([[self tfDelegate]respondsToSelector:@selector(tfDelegateEnded:)]) {
[[self tfDelegate]tfDelegateEnded:[touches anyObject]];
}
NSLog(@"touches ended");
}
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{
[super touchesCancelled:touches withEvent:event];
if ([[self tfDelegate]respondsToSelector:@selector(tfDelegateCancelled:)]) {
[[self tfDelegate]tfDelegateCancelled:[touches anyObject]];
}
NSLog(@"touches cancelled");
}
但是,我了解到 UIScrollviews 通过 UIGestureRecognizers 操作,因此默认情况下甚至不会调用这些方法。我意识到手势识别器在 iOS 5 中公开,但我也需要支持 4.0。我这样做了:
NSArray *a = [[theScrollview gestureRecognizers]retain];
for (UIGestureRecognizer *rec in a) {
if ([rec isKindOfClass:[UIPanGestureRecognizer class]]) {
NSLog(@"this is the pan gesture");
rec.cancelsTouchesInView = NO;
}
}
这允许手势工作和触摸方法同时被调用。问题是,现在如果您在触摸按钮时尝试滚动,则可以在滚动时按下按钮。通常,滚动取消按钮,并且唯一可以按下按钮的时间是滚动视图没有滚动。这是所需的功能。关于我如何实现这一目标的任何建议?