I have an Stackview created in IB and it has Vertical orientation. This stackview has equal width to parent view.
Now I am created a Stackview programmatically for example
let stackViewHorizontal = UIStackView()
stackViewHorizontal.axis = UILayoutConstraintAxis.horizontal
stackViewHorizontal.distribution = UIStackViewDistribution.fillEqually
stackViewHorizontal.alignment = UIStackViewAlignment.leading
stackViewHorizontal.spacing = 8
stackViewHorizontal.translatesAutoresizingMaskIntoConstraints = false
stackViewHorizontal.leadingAnchor.constraint(equalTo: mainStackView.leadingAnchor,constant:0)
stackViewHorizontal.trailingAnchor.constraint(equalTo: mainStackView.trailingAnchor,constant:0)
Here mainStackView is a stackview which is created Via IB.and stackviewHorizontal is a stackview that is created programatically.
I am putting to UILabels inside stackViewHorizontal. I expected this will expand to full length and each UiLabel will take 50% of the screen in width since stackview has horizontal axis and distribution is fillEqually.
But I am having a UiLabels next to eachother horizontally. but not taking full width of screen
What I am doing wrong please notify?
Activate constraints, also give it a height:
stackViewHorizontal.leadingAnchor.constraint(equalTo: mainStackView.leadingAnchor,constant:0).isActive = true
stackViewHorizontal.trailingAnchor.constraint(equalTo: mainStackView.trailingAnchor,constant:0).isActive = true
OR
NSLayoutConstraint.activate([
stackViewHorizontal.leadingAnchor.constraint(equalTo: mainStackView.leadingAnchor,constant:0),
stackViewHorizontal.trailingAnchor.constraint(equalTo: mainStackView.trailingAnchor,constant:0)
])
//
let stackViewHorizontal = UIStackView()
stackViewHorizontal.axis = UILayoutConstraintAxis.horizontal
stackViewHorizontal.distribution = UIStackViewDistribution.fillEqually
stackViewHorizontal.alignment = UIStackViewAlignment.leading
stackViewHorizontal.spacing = 8
self.view.addSubview(stackViewHorizontal) //// add it here
stackViewHorizontal.translatesAutoresizingMaskIntoConstraints = false
stackViewHorizontal.leadingAnchor.constraint(equalTo: mainStackView.leadingAnchor, constant: 0).isActive = true
stackViewHorizontal.trailingAnchor.constraint(equalTo: mainStackView.trailingAnchor, constant: 0).isActive = true
Related
I'm fairly new to iOS app development. I'm trying to make an iOS app which will have an horizontal scroll view with labels added as subviews which exhibit a snapping behaviour. I'm using UIKit and auto layouts (Swift 5, Xcode 12.01) for a programmatically build UI. I have three labels to be added to the scroll view, one is centred, one is offset 500 pt from the scrollview centre (right) and one is at -500 from the centre (left)
When I try to set the scrollview trailing anchor referring to the label on the right I have no problems. However, when I try to set the leading edge referring to the label on the left (leading edge), I encounter the error: [LayoutConstraints] Unable to simultaneously satisfy constraints.
Am I missing something?
I attach my code below:
// Create scroll view on top of bottom view
func createScrollView() -> UIScrollView {
let myScrollView = UIScrollView()
myScrollView.isScrollEnabled = true
myScrollView.backgroundColor = .red
myScrollView.showsHorizontalScrollIndicator = true
view.addSubview(myScrollView)
// Constraints
myScrollView.translatesAutoresizingMaskIntoConstraints = false
myScrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0).isActive = true
myScrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
myScrollView.bottomAnchor.constraint(equalTo: bottomView.firstBaselineAnchor).isActive = true
myScrollView.heightAnchor.constraint(equalToConstant: 50).isActive = true
// Add some elements to the view
let label1 = UILabel()
let label2 = UILabel()
let label3 = UILabel()
label1.text = "EV 0."
label1.font = .systemFont(ofSize: 20)
label1.translatesAutoresizingMaskIntoConstraints = false
label2.text = "ISO"
label2.font = .systemFont(ofSize: 20)
label2.translatesAutoresizingMaskIntoConstraints = false
label3.text = "SNAP"
label3.font = .systemFont(ofSize: 20)
label3.translatesAutoresizingMaskIntoConstraints = false
// Add labels to scroll view
myScrollView.addSubview(label1)
myScrollView.addSubview(label2)
myScrollView.addSubview(label3)
// Add constraint
label1.centerYAnchor.constraint(equalTo: myScrollView.centerYAnchor).isActive = true
label2.centerYAnchor.constraint(equalTo: myScrollView.centerYAnchor).isActive = true
label3.centerYAnchor.constraint(equalTo: myScrollView.centerYAnchor).isActive = true
label1.centerXAnchor.constraint(equalTo: myScrollView.centerXAnchor, constant: -300).isActive = true
label2.centerXAnchor.constraint(equalTo: myScrollView.centerXAnchor, constant: 300).isActive = true
label3.centerXAnchor.constraint(equalTo: myScrollView.centerXAnchor, constant: 0).isActive = true
// Add last constraint in the scroll view
myScrollView.leadingAnchor.constraint(equalTo: label1.leadingAnchor, constant: -500).isActive = true
myScrollView.trailingAnchor.constraint(equalTo: label2.trailingAnchor, constant: 500).isActive = true
return myScrollView
Thanks a lot for your help!!!
I'm trying to add 4 items to a UIStackView, this 4 Items are all a simple square UIView, I added them all to a UIStackView but they won't stay square, it's like the UIStackView squeezes them or something. I tried setting the UIStackView to be the same height of the items, and set it's width to be the height of the items * 4 so I can try and get 1:1 ratio, but nothing worked for me.
The UIView is a simple UIView with background color. I tried to set it's widthAnchor and heightAnchor to 50, but I know the UIStackView has it's own way to size the items in it.
I don't really know what to do about this.
This is my UIStackView setup and constraints:
Setup:
private lazy var optionButtonStack: UIStackView = {
let stack = UIStackView(arrangedSubviews: [self.optionButton1, self.optionButton2, self.optionButton3, self.optionButton4])
stack.translatesAutoresizingMaskIntoConstraints = false
stack.distribution = .fillEqually
stack.axis = .horizontal
stack.spacing = 2.5
return stack
}()
Constraints:
private func setupOptionButtonStack() {
addSubview(optionButtonStack)
NSLayoutConstraint.activate([
optionButtonStack.heightAnchor.constraint(equalToConstant: 50),
optionButtonStack.widthAnchor.constraint(equalToConstant: 200),
optionButtonStack.centerXAnchor.constraint(equalTo: self.centerXAnchor),
optionButtonStack.bottomAnchor.constraint(equalTo: buyNowButton.topAnchor, constant: -8),
])
}
This is the UIView in case this is needed:
private let optionButton1: UIView = {
let view = UIView()
view.backgroundColor = .appBlue
view.translatesAutoresizingMaskIntoConstraints = false
view.widthAnchor.constraint(equalToConstant: 50).isActive = true
view.heightAnchor.constraint(equalToConstant: 50).isActive = true
view.tag = 1
return view
}()
Give the button view a single constraint setting its width equal to its height:
view.widthAnchor.constraint(equalTo: view.heightAnchor).isActive = true
and set the stack view alignment at center.
I have a custom UIView using for Custom UITabBar whose height is fixed 50 and I am adding a stackview for each button but I need middle button height should be more.
let view: UIView = views[3]
view.heightAnchor.equalToConstant(100.0).isActive = true
let stackView: UIStackView = UIStackView(arrangedSubviews: [views])
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.axis = .horizontal
stackView.distribution = .fillEqually
addSubview(stackView)
stackView.topAnchor.constraint(equalTo: topAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
stackView.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
stackView.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
How can I change the height of a particular view inside the stackView?
I may not understand your problem but you can change anyviews height using constraints as you have already done.
It is same when the view is subview of a stackview. Stackview updates it's size to satisfy its constraint.
You have to have a reference to height constraint of the view inside stackview.
Then you can change it whenever need to.
Also it would be nice to set stackviews alignment property to have desired look.
let heightConstraint = view.heightAnchor.equalToConstant(100.0)
heightConstraint.isActive = true
.
.
.
heightConstraint.constant = 150
You want to change the Alignment property of the stack view...
Assuming 5 views, each with a height constraint of 60, and you want the 4th view (views[3]) to have a height of 100.
StackView Alignment Top:
StackView Alignment Center:
StackView Alignment Bottom:
I am trying to achieve a layout like this:
Essentially, I need the or label to stay in the middle and occupy a fixed width and the lines to stretch out towards the edges of the screen.
Here's what I did in the XIB:
created a horizontal UIStackview, with center alignment.
Set the height constraint of the stackview to 20, distribution to fill.
added two UIView elements(for the gray lines), with a height constraint set to 5.
Added a UILabel between the two UIView elements above.
Added more constraints:
left UIView leads with 0 from superview and trails with 5 to middle label
right UIView leads with 4 from middle label and trails with 0 to superview.
Looks fine on the Interface builder, but on different screen sizes and landscapes, I find the middle "or" label to stretch and kick away the left and right UIViews to make up for the available space, which seems right:
If I set a width constraint of 20 on the middle label, the right UIView stretches unevenly like this:
I know the CHP of the elements matters to some extent here, I have even tried setting CHPs like this:
CHP of the middle label is 251
CHP of left and right UIViews is 250.
This still leaves me with the uneven stretching of right UIView.
What is it that I am doing wrong? Insights much appreciated!
Thanks a lot!
You need to set widthConstraint on UIStackView and the make leftView.widthAnchor = rightView.widthAnchor. Alternatively you can set leading and trailing constraints on UIStackView and then set leftView.widthAnchor = rightView.widthAnchor.
Below is the sample code you can try out in Playgrounds
let leftView = UIView()
leftView.translatesAutoresizingMaskIntoConstraints = false
leftView.backgroundColor = .lightGray
let rightView = UIView()
rightView.translatesAutoresizingMaskIntoConstraints = false
rightView.backgroundColor = .lightGray
let orLabel = UILabel()
orLabel.translatesAutoresizingMaskIntoConstraints = false
orLabel.textColor = .black
orLabel.text = "or"
let stackView = UIStackView(arrangedSubviews: [leftView, orLabel, rightView])
stackView.alignment = .center
stackView.distribution = .fill
stackView.axis = .horizontal
stackView.spacing = 5
stackView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(stackView)
stackView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
stackView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
stackView.heightAnchor.constraint(equalToConstant: 20).isActive = true
stackView.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true
leftView.heightAnchor.constraint(equalToConstant: 5).isActive = true
rightView.heightAnchor.constraint(equalToConstant: 5).isActive = true
leftView.widthAnchor.constraint(equalTo: rightView.widthAnchor).isActive = true
Don't set any leading or trailing constraints...
Set "right view" width constraint equal to "left view" width, and give your stack view a spacing value of 4 or 5.
Storyboard:
Portrait:
Landscape:
I am currently making a calculator and want to change the size of my 0 button to the size of 2 subviews - which is half the size of the entire view. I want it to look exactly like apples calculator app, where the 0 is bigger than all the other buttons.
The way i layout my view is by having a vertical UIStackView and adding horizontal UIStackView's to it, just like the picture below.
Therefore, i want the last horizontal stack to have 3 arranged subviews but make the 0 button fill the exceeding space, so the , and = buttons are the same size as all other buttons.
Thank you.
Programmatically, you could set multiplier with constraint(equalTo:multiplier:), official docs: https://developer.apple.com/documentation/uikit/nslayoutdimension/1500951-constraint
So we could constraint the last two button with same width and make the first one two times longer than one of the other two.
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
let btn1 = UIButton()
let btn2 = UIButton()
let btn3 = UIButton()
btn1.backgroundColor = .red
btn2.backgroundColor = .yellow
btn3.backgroundColor = .blue
let hStack = UIStackView(arrangedSubviews: [btn1, btn2, btn3])
hStack.axis = .horizontal
hStack.spacing = 1
view.addSubview(hStack)
hStack.translatesAutoresizingMaskIntoConstraints = false
hStack.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
hStack.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
hStack.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
// Here would be what you need:
btn2.widthAnchor.constraint(equalTo: btn3.widthAnchor).isActive = true
btn1.widthAnchor.constraint(equalTo: btn2.widthAnchor, multiplier: 2).isActive = true
}
You can use stackview.distribution = .fillEquallly for first 4 horizontal stackviews and use stackview.distribution = .fillPropotionally for the last horizontal stackview.
Then set with constraint for the 0 button to 50% of last horizontal stackview's width.