In my application I have added a UIButton with following constraints:
Leading space = 10
Trailing space = 10
Height = 50
Bottom space =10
By this I got a button placed at a bottom of device. It works good on single device(iPhone 4), but as device height increases button height remains same(iPhone 6).
I want to change button height also with Autolayout.
I tried some example which suggest to add multiplier value but no luck.
I am using Xcode-8 with Swift3
Please suggest me.
There is multiple way to handle this issue
First:-
Create 1,Give Fixed Height Constraint to button
2.Create #IBOutlet of Height Constraint
like this way
#IBOutlet weak var btnHeightConstraint: NSLayoutConstraint!
3. Set Constraint constant as per your requirement
like this way.
btnHeightConstraint.constant = 50 //your button height 50
btnHeightConstraint.constant = 60 //your button height 60
Set all the constarints which is needed and set 'Equal Height' constraint with your 'superview' and set the multiplier value i.e if your view size is same as iphone 5 then set multiplier value as 'yourHeight:568', you will get required output.
Related
I want the DecriptionLabel (the Lorem Ipsum one) to have all the text inside it visible. As you can see, it is getting trimmed.
The two buttons should be under everything else, but in the case where DescriptionLabel contains a small text, the buttons should stick to the bottom of the view.
This is why I chose a >= 20 distance between the buttons and DescriptionLabel if it makes any sense.
How can I solve the trimming of the text?
Thanks.
I was originally answering How to make button stick to bottom of scroll view if the content isn't large enough? but since it is marked as duplicate of this one I am posting my answer here. Please try to set your constraints the following way: https://imageshack.com/a/img923/6671/Txzu98.png
The trick is that you set Button.Bottom Equal To ContainerView.Bottom with lower priority (I use 750) than Button.Top Greater Than Or Equal To Label.Bottom (Here I use default 1000)
The Label has to have number of lines set to 0. The height of the button should be set by height constraint (in this case is 50). The Container View Height constraint should be with low priority (in this case 250)
You should run the code to see actual result on device or simulator. Storyboard shows it a bit differently. For the current question:
https://imageshack.com/a/img923/7276/tQeT0h.png The basic idea is the same. Button Down has the same constraints as Button from above answer without Button.Top Greater Than Or Equal To Label.Bottom. There should be fixed vertical constraint between Button Up and Button Down. I am setting Button Up with fixed Height and setting trailing and leading constraint equal to trailing and leading of Button Down. The constraint Button.Top Greater Than Or Equal To Label.Bottom is now Button Up.Top Greater Than Or Equal To Label.Bottom
Have you set numberOfLines for label to 0 (that means autosize the label according to its text length)?
You should add the following constraints:
(following in sudo code)
// Constraints for ScrollView
scrollView.top = ViewController.view.top
scrollView.leading = ViewController.view.leading
scrollView.trailing = ViewController.view.trailing
scrollView.bottom = ViewController.view.bottom
// Constraints for View
view.top = scrollView.top
view.leading = scrollView.leading
view.trailing = scrollView.trailing
view.bottom = scrollView.bottom
// Width of view
view.width = ViewController.view.width
Now you just need to make sure you have layout constraints for each child of the 'view' and it's height will be correct and display the full size of the textview.
Add the following constraint:
scrollview.contentview.height >= safearea.height
This may show an error in interface builder but works in my tests:
To remove the design time error you could set a design time intrinsic content size for the scrollview's contentview (in my case I used the safe area's height of 554):
Another option (without placeholder values in IB) is to create the following constraint...
scrollview.contentview.height = safearea.height
... and change its priority to a value lower than the label's vertical content compression resistancy.
I have Imageview and UIView on View Controller. If Imageview is nil or image is not available then UIView replace its postion.Do any know how is it possible using auto layout?
For trying purpose, I have fixed height and width of both(Imageview and UIView). Imageview have "top 8 pixel" and "Horizontally in container" margin. UIView have "top 0 from Imageview" and "Horizontally in container" margin. Set Imageview to nil but it doesn't work.
A good suggestion would be to add both of the image view and the view in a stackView and follow the steps mentioned in: UIStackView Distribution Fill Equally.
However, you can achieve what are you asking for by adding additional constraint between the bottom view and the top layout guide:
and then, set its priority value to be less than the default (1000) -in my example I set it to 500- and the its constant value to 0:
Its appearance should be displayed as dotted line, meaning that there is another constraint -with a higher priority value- deciding the x axis of the view, if this constraint has been removed/deactivated the dotted one should be activated.
Finally, make sure that if there is no available image you have to remove image view from its super view (call imageView.removeFromSuperview()), setting it as hidden or setting its alpha to 0.0 doesn't activate the dotted constraint:
class ViewController: UIViewController {
//...
#IBOutlet weak var imageView: UIImageView!
// I'm checking in 'viewDidLoad' method just for describing purposes,
// of course, you can do the check when needed...
override func viewDidLoad() {
// if there is something wrong, you should call:
imageView.removeFromSuperview()
}
//...
}
The output would be:
Take the outlet of height constraint of UIImageView and do below code
if (imageview == nil){
imageViewHeightConstraint.constant = 0
}
else{
imageViewHeightConstraint.constant = 60
}
And other query you can ask.
You can manage this by giving priority to the constraints using auto layout. Give your UIView top space from ImageView and the TopLayout. Assign a lower priority to the constraint (any value less than 1000) where you have given top space from top layout guide. If your image is nil , remove the image view from the view using imageview.RemoveFromSuperView(), the UIView will automatically take the next constraint i.e. from TopLayout guide. I am attaching a screenshot where to find the priority of the constraint on storyBoard.
As I am new to iOS. So forgive me if it is duplicate or very basic question.
I am taking one View. Approx below is the size .
x : 5 y : 5
Width : 590 Height : 100
and I set constraint it
Top to superView 5
Trailing to superView 5
Leading to superView 5
Now I have one Label which have dynamic Text and the Text is too large.
And the Label Constraint is below
Top to superView 5
Trailing to superView 5
Leading to superView 5
and when i set the background color of the View the color is not set. If the Text is to Long. So how to set the Height of the View and also set background so that it looks clear.
Code :
public override void ViewDidLoad()
{
base.ViewDidLoad();
lbl_one.Text = "This is a long label which have long text inside the writing. This is a long label which have long text inside the writing. This is a long label which have long text inside the writing. This is a long label which have long text inside the writing";
lbl_one.LineBreakMode = UILineBreakMode.WordWrap;
lbl_one.Lines = 0;
view_main.BackgroundColor = UIColor.Red;
}
If I give fix Height then it look like this .
Output :
1. Give the below constraints to your view, height is according to your need. here I'm giving 80.
2. Change the height relationship.
3. Add aUILabel in your above UIview, and give below constraints.
--> leading, top, bottom, trailing to uiview and height i.e. 80.
4. set height relationship as you do with UIView.
5. Change the property of UILabel , Lines to zero
6. Now enjoy with your constraints.
EDIT: Add bottom constraint to your view instead of height constraint.
I don't see and bottom constraint added to UIView, so the view height will be 0.
If you have added the height constraint to UIView, there is a probability that UILablel might be overlapping the UIView, so you are not able to see the background color.
Set the UIView height constraint this will solve your problem
You can also add height or bottom constraint to your UIView.
I have set constraints on Storyboard, and tried to center CollectionView horizontally and give an extra offset.
I tried logging constraints on console by using this and consoled all the constraints.
print(collectionView.constraints)
How can I overwrite 30 offset to 50 offset (for example) programmatically?
Create an IBOutlet to the constraint you wish to overwrite.
#IBOutlet weak var collectionViewCenterXConstraint: NSLayoutConstraint!
then whenever you want to change it.
collectionViewCenterXConstraint.constant = 50 // the offset will be 50 now.
I have a circle in the centre of a screen with a margin constraint of 50 on either end. Hence, the width of the circle is dependent on the screen size.
So, what I tried was this:
Approach 1
I set up the margins in the storyboard to define the circle width (50 on left and right)
Then I used the following code:
#IBOutlet weak var helpButHeight: NSLayoutConstraint!
#IBOutlet weak var helpBut: UIButton!
ViewDidLoad:
helpButHeight.constant = helpBut.frame.size.width
This didn't work.
Since the screen width is 400, and the margin is 50 on either end, then helpBut.frame.size.width should have given me 300.
Instead it gave me 46.
Approach 2
This was my work-around:
ViewDidLoad:
let screenSize: CGRect = UIScreen.mainScreen().bounds
helpButHeight.constant = screenSize.width - 100
because 100 = 50 + 50, the two margins.
Works fine !
Question
Why did I have to do this? Why did the first approach not work? Why 46 and not 300?
The reason is that constraints haven't kicked in, in the viewDidLoad function. The lifecycle looks something like
viewDidLoad -- Constraints haven't set
viewWillAppear -- Constraints haven't set
viewWillLayoutSubviews -- Constraints are setting
viewDidLayoutSubviews -- Constraints are set
viewDidAppear -- Constraints are set
If you want any view to be in center just put the horizontal/vertical center constraint...No code required.. If you want to have padding just put the left and right constraints...Just to remind you don't use both of them together...It'll break...