UIScrollView不垂直滚动

Question

I made iPhone app in which I have this hierarchy,

: When I try to scroll my scrollview it doesn't scroll I am using Autolayout in my project

content size of my scrollview is greater then the height of my scrollview still it doesn't scroll.

Here is my code snippet wrote in viewDidLoad

    UIView *tempo = (UIView *)[scrollVw viewWithTag:6];//View which is inside Scrollview

    float sizeOfContent = 0;
    for (int i = 0; i < [tempo.subviews count]; i++) {
        UIView *view =[tempo.subviews objectAtIndex:i];
        sizeOfContent += view.frame.size.height;

    }

    NSLog(@"sizeOfContent = %f", sizeOfContent);
    scrollVw.contentSize = CGSizeMake(scrollVw.frame.size.width, 1500);

    NSLog(@"scrollVw width = %f -- scrollVw height =%f",scrollVw.frame.size.width, scrollVw.frame.size.height);

    NSLog(@"tempo width = %f -- tempo height =%f",tempo.frame.size.width, tempo.frame.size.height);

Log Result:

sizeOfContent = 1500
scrollVw width = 320.000000      scrollVw height = 416.000000 
tempo width = 320.000000         tempo height =  416.000000

Where I am doing mistake?

Answer 1

If you are using autolayout, then your views are ultimately layed out after viewDidLoad. So move your code into viewWillAppear or viewDidLayoutSubviews and you should be fine.

Answer 2

Please try to call this method after setting your content size

scrollVw.contentSize = CGSizeMake(scrollVw.frame.size.width, 1500);

[scrollVw layoutIfNeeded];

Answer 3

Where are you logging your contentSize etc? In viewDidLoad?

What does it show in viewDidLayoutSubviews? I think your constraints are messing with your content size.

Answer 4

hope this will help you

, when you use a UIScrollView with auto layout the auto layout not works like you expect from it.(Your image showing a red arrow before going any where else please click that and adjust your auto layout )

View (main view of my UIViewController) – with
-Scroll View (UIScrollView)
--Container View 
----Content1 
----Content2 (etc)

-> The scroll view must have at least 1 content that attaches to each of its edges, eg top, left, right, and bottom(Container View ).

-> Do not fix the height, width of scroll view just give 4 constraint to it(leading, trailing, top, and bottom ).

->give Container view leading, trailing, top, and bottom spaces to the Scroll View.

and give constraint to inner Content. then

if(self.viewScroll.contentSize.height>self.viewScroll.frame.size.height)
{
    [self.viewScroll setScrollEnabled:YES];
}
else
{
    [self.viewScroll setScrollEnabled:NO];(if you want)
}

Answer 5

从viewcontroller取消选中autolayout，然后尝试并确保contentsize.height不仅仅是scrollview高度。

Answer 6

I think it's ok if your scrollview's height (568) is greater than the scrollview.contentsize(eg 350). The only thing that helped me, is to change the contentmode of the Imageview that we put on the scrollview as:

imgView.contentMode = UIViewContentModeScaleToFill;

You don't even need to access the method scrollViewDidEndZooming this way.