UIScrollView滚动条一直显示
1.我们知道滚动条是一个UIImageView, 滚动条隐藏是因为设置了alpha属性为0, 所有我们写一个UIImageView的分类
#define noDisableVerticalScrollTag 836913
#define noDisableHorizontalScrollTag 836914
@implementation UIImageView (WLScrollView)
- (void)setAlpha:(CGFloat)alpha
{
if (self.superview.tag == noDisableVerticalScrollTag) {
if (alpha == 0 && self.autoresizingMask == UIViewAutoresizingFlexibleLeftMargin) {
if (self.frame.size.width < 10 && self.frame.size.height > self.frame.size.width) {
UIScrollView *sc = (UIScrollView*)self.superview;
if (sc.frame.size.height < sc.contentSize.height) {
return;
}
}
}
}
if (self.superview.tag == noDisableHorizontalScrollTag) {
if (alpha == 0 && self.autoresizingMask == UIViewAutoresizingFlexibleTopMargin) {
if (self.frame.size.height < 10 && self.frame.size.height < self.frame.size.width) {
UIScrollView *sc = (UIScrollView*)self.superview;
if (sc.frame.size.width < sc.contentSize.width) {
return;
}
}
}
}
[super setAlpha:alpha];
}
@end
2.写完分类之后, 我们在初始化UIScrollView的时候设置UIScrollView的tag为836913
3.要在UIScrollView数据绑定之后, 调用以下方法
- (void)flashScrollIndicators; // displays the scroll indicators for a short time. This should be done whenever you bring the scroll view to front.
即调用以下方法
[scrollView reloadData];
[scrollView flashScrollIndicators];