I'm adding a few subviews to a UIScrollView and setting its contentSize, like this:
let cellWidth: CGFloat = 100.0
let cellHeight: CGFloat = 100.0
for i in 0...10 {
let view: UIView = UIView(frame: CGRectMake(CGFloat(i) * cellWidth, 0, cellWidth, cellHeight))
view.backgroundColor = UIColor.randomColor()
self.scrollView.addSubview(view)
}
self.scrollView.contentSize = CGSizeMake(10 * cellWidth, cellHeight)
This is what I get:
I don't really understand why these subviews aren't drawn at y=0
There are no constraints applied in the storyboard to this UIScrollView.
I have found the reason for this.
For anyone with the same problem, just go to interface builder and select the troubling UIViewController.
In the 'Attributes Inspector' section, on the right pane, untick 'Adjust Scroll View Insets'.
Related
I am trying to expand my view when tableViewCells are added to the tableview to scroll the whole view rather than the table, but my implementation of increasing the size of the tableView and the ScrollView isn't quite working, I'm not sure if it has something to do with the code or the constraints set. What sort of constraints would I have to set in story board to make this work?
This is what I've tried and it isn't expanding the scroll view:
#IBAction func addExercisePressed(_ sender: Any) {
test.append("nice")
tableView.isScrollEnabled = false
tableView.frame = CGRect(x: tableView.frame.origin.x, y: tableView.frame.origin.y, width: self.view.frame.size.width, height: CGFloat(tableView.visibleCells.count * 120))
scrollView.contentSize = CGSize(width: self.view.frame.size.width, height: tableView.frame.size.height)
tableView.reloadData()
}
tableView.visibleCells.count isn't the same as number of cells at some time , also you need to use auto-layout constraints by giving the table in IB a default height and hooking it as an IBOutlet then inside viewDidLayoutSubviews/viewDidAppear do
self.tableHeight.constant = numOcells * 120
self.view.layoutIfNeeded()
I'm creating a application using Swift3, and i have difficult to define correctly height for UIScrollView, i'm using autolayout and create this structure:
UIScrollView
UIView // The container view
UIImageView // Constraint Top Edges = 20 in relation to UIView
UITextView // Constraint Top Edges = 40 in relation to UIImageView
UITextView // Constraint Top Edges = 20 in relation to UITextView
UIButton // Constraint Top Edges 30 in relation to UITextView
Currently, i'm using this logic to calculate UIScrollView height
override func viewDidLayoutSubviews() {
var scrollHeight : CGFloat = 0.0
for view in self.containerView.subviews {
view.layoutIfNeeded()
scrollHeight += view.frame.size.height
}
// Adding height for scrollview, according to the sum of all child views
self.scrollView.contentSize.height = scrollHeight
}
But, i can only get the views height, and them not consider the Constraints "margins", i would like know any way to calculate correct height for UIScrollView, adjusted according their content.
Close! Let's add the top margin for each view:
override func viewDidLayoutSubviews() {
var scrollHeight : CGFloat = 0.0
for view in self.containerView.subviews {
view.layoutIfNeeded()
scrollHeight += view.frame.size.height
//Add the margins as well to the scrollHeight
scrollHeight += view.layoutMargins.top
}
// Adding height for scrollview, according to the sum of all child views
self.scrollView.contentSize = CGRect(x: self.scrollView.contentSize.width, y: scrollHeight)
}
self.scrollview.contentsize.height = containerview.height;
I've some problem with ScrollView.
I'm trying to create a scrollview and add to it dynamically some buttons.
So i create a scrollView in my main storyboard with some constraints. (0 to left, 0 to right, 0 to botton and 1/10 height).
Now, i want to add some button.
#IBOutlet var scrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
for index in 0..<12 {
let frame1 = CGRect(x: 0 + (index * 60), y: 0, width: 45, height: 45 )
let button = UIButton(frame: frame1)
button.setTitle("toto", forState: .Normal)
button.backgroundColor = UIColor.green()
scrollView.addSubview(button)
}
}
So now the problem is : my buttons are present but i can't scroll. The scroll is enabled in the storyBoard. I tried to enabled it in the code but nothing changed..
set the contentSize of your scrollView
self. scrollView.contentSize = CGSizeMake(required_width, required_height)
for example
self. scrollView.contentSize = CGSizeMake(500, 74) // custtomize ur self
You have to set the contentSize of the scrollView
The height to set is probably the origin.y + the size.height of the last button.
use this code to set scrollview height
scrollview.contentInset = UIEdgeInsetsMake(0, 0, 50, 0)
//50 is the height of scroll view you can change it to the height you want
scrollview.bounces = false
or you can also change content inset from here
by changing the values of content inset (height or width)
I have a UIScroll view which contains only one subview. The subview called contentViewis an UIView. Here is what I did in viewDidLoad():
self.scrollView = UIScrollView()
self.view.addSubview(self.scrollView)
self.scrollView.backgroundColor = UIColor.yellowColor()
// pin all edges to the edges of the superview (self.view)
self.scrollView.snp_makeConstraints { (make) -> Void in
make.edges.equalTo(self.view)
}
// create contentView
self.contentView = UIView()
self.contentView.backgroundColor = UIColor.redColor()
self.scrollView.addSubview(self.contentView)
// pin the edges of the contentView to the scrollView
self.contentView.snp_makeConstraints { (make) -> Void in
make.edges.equalTo(self.scrollView)
}
let myView = UIView(frame: CGRectMake(100, 100, 20, 300))
myView.backgroundColor = UIColor.greenColor()
self.contentView.addSubview(myView)
The result is this:
There is ne red contentView as shown in the previous screen shot.
Next, I tried to adjust the size of the contenView in viewDidLayoutSubviews():
let newSize: CGSize = self.contentView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
println("newSize: \(newSize)")
The result is:
newSize: (0.0, 0.0)
How can I either setup the correct size of the contentView or set the correct size of the UIScrollView's contentSize?
have you tried setting the var contentSize: CGSize of the UIScrollView? The documentation says
Discussion The unit of size is points. The default size is CGSizeZero.
If you don't know the size of the content view, then I would recommend setting
scrollView.autoresizingMask = (UIViewAutoresizingFlexibleWidth| UIViewAutoresizingFlexibleHeight);
and
scrollView.autoresizesSubviews = YES;
for good measure.
I am using UIScrollView with Auto-layout to change contentSenter code hereize value as following :
UIView
ScrollView
UIView (contentView)
In run time I am adding UITextView & UIImageView to conentView with constraint(Top,Bottom,Left,Right)
but the contentView size is not changing and UIScrollView contentSize also.
So what could be the problem ?
In run time I am adding UITextView & UIImageView to conentView with constraint(Top,Bottom,Left,Right)
Maybe you should add constraint (Top, Left, Height, Width),or (Top, Left, Right, Height)
If you persist in (Top,Bottom,Left,Right), ScrollView will keep the old content size, and make your UITextView & UIImageView (Height = 0, Width = 0).
Here's a neat way of updating scroll view's content size. It's Swift so you'll need a bridging header if you're working in Objective C.
extension UIScrollView {
func updateContentViewSize() {
var newHeight: CGFloat = 0
for view in subviews {
let ref = view.frame.origin.y + view.frame.height
if ref > newHeight {
newHeight = ref
}
}
let oldSize = contentSize
let newSize = CGSize(width: oldSize.width, height: newHeight + 20)
contentSize = newSize
}
}
Just call it on your scroll view's object whenever you add a child view to your scroll view.