ios - 遍历 UIView.subviews 获取按钮很快

Question

在我的 Objective-C 代码中，我可以使用此方法来查找 view.subviews 的 按钮:

-(UIButton*)findButtonInView: (UIView*)v {
    for (UIView *subView in v.subviews) {
        if ([subView isKindOfClass:[UIButton class]]) {
            return (UIButton*)subView;
        }
        else if ([subView isKindOfClass:[UIView class]]) {
            UIButton* btn = [self findButtonInView:subView];
            if(btn) {
                return btn;
            }
        }
    }
    return nil;
}

UIButton* searchButton = [self findButtonInView:self.searchBar];

但是我怎样才能创建一个方法来通过 Swift 在 view 中查找 button 呢？

如您所知，我无法像此 Swift 方法那样返回 nil:

class func findButtonInView(_ view:UIView) -> UIButton {}

Answer 1

class func findButtonInView(_ view:UIView) -> UIButton?{}