Question

我一直在试图弄清楚如何将UIScrollView的触摸转发到其superview。原因是要按照触摸的方式对光标进行排序。无论如何，滚动视图填充了UIButtons。我转发触摸的代码是在scrollview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是通过UIGestureRecognizers进行操作的，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中暴露，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，现在如果您尝试在触摸按钮时滚动，则可以在滚动时按下按钮。通常，滚动取消按钮，并且只有滚动视图不滚动时才能按下按钮。这是所需的功能。关于如何实现这一目标的任何建议？

Answer 1

也许尝试使用一个标志来控制按钮操作，如果滚动视图正在滚动，则会阻止事件触发。

BOOL isScrolling = NO;

- (void) scrollViewWillBeginDragging:(UIScrollView *)scrollView {
    isScrolling = YES;
}

- (void) scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
    isScrolling = NO;
}

- (void) didTapButton {

    if(isScrolling)
        return;

    //Do Button Stuff
}

来自UIScrollView的转发 - UIButton问题

1 个答案: