Can't add a UIScrollView to a part of the view

Question

Inside a UIViewController, I need to have the bottom half scrollable. So I added a UIScrollView and positioned it halfway down the view's height. And in the viewDidAppear method, I have put the below two code lines to make it scrollable.

self.scrollView.contentSize = CGSizeMake(self.view.frame.size.width, self.scrollView.frame.size.height);
self.scrollView.frame = self.view.frame;

This way works if the scroll view fills the entire view, I've tested. But this method didn't work for my need. The scroll view would automatically move up and take up the entire screen. I assumed it was the second line of code which causes this.

So I removed the scroll view, added two UIViews to the view controller. To the bottom view, I added the UIScrollView. And in the viewDidAppear method, I have put the same two code lines changing the second line to refer the frame of the UIView that contains the scroll view..

self.scrollView.contentSize = CGSizeMake(self.view.frame.size.width, self.scrollView.frame.size.height);
self.scrollView.frame = self.containerView.frame;

But it wouldn't scroll either.

Can anyone please tell me how to do this correctly?

Thank you.

Answer 1

Dude, you keep setting the frame of the scrollView to something completely different from what you're actually trying to achieve.

If all you want to do is setup your scroll view so that it only occupies half the space then why dont you just set the frame so that the height only covers the portion of the screen that you want it to cover; and then set the x & y coordinates so that you draw the scroll view from the right position.

Do something like this:

//Shortcut to view's frame.
CGRect viewsFrame = self.view.frame;

/**
CGRectMake takes 4 parameters: x, y, width, height
x: is set to 0 since you want the scrollview to start from the left with no margin
y: you want the y position to start half way, so we grab the view's height and divide by 2  
width: you want your scrollview to span from left to right, so simply grab the view's width
height: you want your scrollview's height to be half of your screen height, so get view's height and divide by 2.
*/
CGRect frameForSV = CGRectMake(0, viewsFrame.size.height/2, viewsFrame.size.width, viewsFrame.size.height/2);

UIScrollView *myScrollView = [[UIScrollView alloc] initWithFrame:frameForSV];
[self.view addSubview:myScrollView];

Then set your content size not based on an ansolute value, its best to have it based on the size of the content that's actually inside your scrollview so that your scrollview always scrolls to cover all your content inside it.

Also, remember that your scrollview will only scroll if the contentsize is greater than the scrollview's frame

UPDATE 1 after reading your comment in this post simply comment out any code in your viewController.m file related to your scrollview since youre setting up everything in interface builder.

This is the result: