水平鍋內部垂直滾動視圖

Question

我的滾動視圖僅限於垂直滾動。 在其中，我想使用UIPanGestureRecognizer來僅識別水平平移的視圖。

同樣，水平識別器也會獲勝並完全阻止滾動視圖滾動。

我希望水平平移在檢測到大部分為水平手勢時獲勝，否則垂直滾動應會獲勝。 與郵箱的工作方式非常相似，或在iOS8 Mail.app中滑動

Answer 1

您可以使用UIGestureRecognizerDelegate方法之一（例如gestureRecognizerShouldBegin:來指定在哪種情況下觸發哪個平移手勢。

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {

    // If the gesture is a pan, determine whether it starts out more
    // horizontal than vertical than act accordingly
    if ([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]]) {

        UIPanGestureRecognizer *panGestureRecognizer = (UIPanGestureRecognizer *)gestureRecognizer;
        CGPoint velocity = [panGestureRecognizer velocityInView:self.view];

        if (gestureRecognizer == self.scrollView.panGestureRecognizer) {
            // For the vertical scrollview, if it's more vertical than
            // horizontal, return true; else false
            return fabs(velocity.y) > fabs(velocity.x);
        } else {
            // For the horizontal pan view, if it's more horizontal than
            // vertical, return true; else false
            return fabs(velocity.y) < fabs(velocity.x);
        }
    }
    else
        return YES;
}