i'm back developing IOS after a year and a half. I'm really having difficulty in make use of UIScrollView and auto layout.
I'm developing an application running just in Iphone and portrait orientation.
I have a simple form inside my content view...
label
textField
textField
textField
textField
button
textField
view
imageView
label
The problem is with the width of the contentView's content. The size is been defined for the labels. I would like (And really have to do) o size it according with the screen size.
Here is my constraints of my first text field:
Here is my simulator screen running the app:
how I mentioned before, it seems to get the size according the label and not according the screen size. If I create a constraint of size for the first label, this size change but I would like to get the size dinamically based on screen.
I didn't write any code, I want to do it preferentially using auto layout to understand the concepts of auto layout better.
If someone could help me to solve it... I would be very grateful.
Pin your contentView.width equal to scrollview.width.
Add a constraint to your scroll view's content view child to be the same width as the root-level view.
Related
I was trying to practice Auto Layout in iOS, and I started with very simple UI. Please see image for understanding my problem.
All the text files are in middle of screen (I have deliberately kept on guide line), still you can see in preview, controls are not fully shown. I have not chosen specific size. Size is 'Inferred' still I am not able to see all the controls on UI.
I tried both adding and removing Auto Layout, but no luck. What should I do to create generic UI which will work with all the sizes of iPhone and iPad.
This image is without use of Auto Layout.
After enable autolayout and size classes you have to apply autolayout constraints.
Autolayout is a detail topic. Few basic things when applying autolayout is:
UI element need four constraints.
position x
Position y
height
width
So you will select first label (Number 1). Then press control and drag to superview. You will be provide options. Select Leading space (This will handle x position)
This is the way you can press control and drag:
http://www.appcoda.com/wp-content/uploads/2014/07/auto-layout-login-trailing.gif
Go to size inspector. You can see the constraint.
Press edit and change its value to 25(for test).
similarly control and drag again to superview and select Top space. (This will set y position for label)
This is simple way for the above taken from AppCoda
http://www.appcoda.com/wp-content/uploads/2014/07/auto-layout-control-drag.gif
You can change the value of these constraints according to your need.
UILabel and uitextfield get width and height from their content size. So don't need width and height constraints.
Now when you preview on any device this label will be stick on top left side of screen.
So this is a complete mechanism. You have to apply constraint to every ui element.
Below is a link to very comprehensive tutorial by
http://www.raywenderlich.com/115440/auto-layout-tutorial-in-ios-9-part-1-getting-started-2
At start this tutorial tried to create three views using autolayout. At the end it shows very similar scenario like yours by applying constraints to button and labels.
The problem here is that your constraints are not set correctly to work with every size of iPhone and iPad. You are setting the leading edge constraint to be a fixed size from your view controller's view to the subviews.
The simplest way to solve this issue would be to have a container view that you center in the view controller's view and then use constraints to set 'Center X Alignment Constraint' and 'Center Y Alignment Constraint' to set the container view's center to that of the view controller and then add your subviews to the container view.
As a side note auto layout has a reputation of being hard to learn, you have to put the time in to learn it, I would start with Apple's Auto Layout Guide.
I am trying to create a static tableview for sign up form. I have label and textfields. I want to apply auto layout such that label and textfields are visible but I am not able to achieve that for iPhone but it seems to work for iPad, since, I guess iPad are bigger. I have applied height and aspect ratio constraint to textfield. I have pinned labels to the left edge of the textfield.
I used the view (with thickness 2) and centered it vertically and horizontally to use as a reference point.
Actual image is.....
->View controller
->view
->ScrollView[[top,bottom,leading,trailing]to its super view]
->contentView[[top,bottom,leading,trailing,vertical,horizontal]to its scrollview].
that actual image is for iphone6 ->iphone4s,Any one help me how to do this.....
When it comes to set constraint with scrollview then little bit extraa effort is required for handling scrolling so that Scrollview + autolayout works.
First of All What exactly take place when autolayout is used :
When you use the auto layout, your views will resized automatically based on the constraint properties.
But, when you use a UIScrollView with auto layout like a container, the auto layout not works like expected.
so Here is Very good tutorial g8production which clears this confusion. Big Thanks goes to g8Production for providing this tutorial.
I think you are setting the constraints for content view in wrong way. You are trying to set the constraints on contentView that are related to its container(scrollview) which don't know content size of its own. It determines its content size from what it contains (in your case contentView,). Both are dependent to each other for their size. So both are confused.
To solve this you should first set the fixed height and width of contentView and then make outlets of these constraints and update these constraints with the height and width of superview when your view loads.
add top, bottom , leading and trailing space to your scroll view to view. It should be set accordingly, how you you want it to be seen. Then set same for content view (image). just addheight and width constraint for your image.
Misha :)
I have a UILabel in my storyboard which i want to align from bottom and whose width and height want to get adjusted in portrait and landscape.
For this, i dragged in a UILabel pinned its leading space, trailing space, bottom space to its superview.
I did not pin its width and height since i wanted its width and height to be changed during its landscape rotation.
With this i got a warning in story board where i have selected to update frame, which automatically adjusted the frame and made it work correctly.
Now i am trying to achieve same kind of behaviour with UICollectionView but this is not working as expected, instead it is giving out some errors saying 'misplaced view' and 'missing constraints'.
I am aligning buttons in 2 rows and 3 columns in the collection view in portrait mode and want to align all the 6 in single row in landscape mode, so if i pin the height here.
The problem is it will go good for portrait mode but in landscape the height will seem higher. Any help on how this could be achieved.?
You got errors because you did not added the constraint for the collection view top layout or height or aspect ratio. it is necessary to assign all side constraint so the view will automatically layout according to the constraint. if you miss one it will give you error or warning. Look you want dynamic height for collection view. If you want to achieve this for all the devices like for all iphones then you need to pin the height and make a outlet of the height constraint and change it in your viewDidLayoutSubviews method. select the collection view then go to size inspector and double click the height constraint. this will show you the constraint on the document outline. make outlet of that and change that constraint according to your need like on portrait or landscape you can calculate with logic. you might need to change the constraint according to the orientation change. follow https://stackoverflow.com/a/24072010/4030971
i know that will be great if all those stuff work only with some constraint but i found this way easier for me.
I really hate to ask here because I usually try to figure things out on my own. But on this one I've stuck for days and can't find a solution anywhere online.
I have a ScrollView containing multiple subviews. I've got an image view and two labels at the top with fixed heights. Then there is a UITextView and another ImageView (see pictures).
I add the text to the text view programmatically so it should have a dynamic height and the ImageView should move to the bottom so you can scroll. I don't want the TextView to be scrollable in itself but I want all the subviews to move as well.
I know I should be able to solve this issue using constraints. But I feel like I've tried everything and nothing worked yet. It worked when I disabled auto layout and moved the views manually. I'm wondering if there is a better way though.
As you can see I pinned the TextView to the ImageView above with a 1,000 priority and to the ImageView below with a 1,000 priority. The height constraint can not be deleted so I set it to the lowest possible priority. The ImageView on the bottom is pinned to the bottom of the superview with an absolute height. Its height constraint also has low priority. (I can post an image of the ImageView's constraints, if it helps)
I also tried adapting the frame programmatically but this is not working well in combination with auto layout. (If it helps I can of course post the code)
What am I doing wrong? Shall I just disable auto layout and do it manually? This seems unclean to me. Is it even possible to do?
I really appreciate your help :)
Greets,
Jan
Make sure the Scrolling Enabled attribute on the UITextView is unchecked in Interface Builder. I believe that the Auto Layout system takes that into account when it calculates the intrinsic content size.
If somebody is struggling with a similar problem: This is what I ended up doing:
Remove all subviews from the ScrollView in IB
Programmatically add a single UIView to the ScrollView.
Add all the views to the UIView as subviews (move them using setFrame)
Set the Frame of the UIView appropriately to the subviews
Set the ScrollView's contentSize to the size of the UIView.
A little more work but it finally works. This follows Apple's mixed approach guidelines that can be seen here (look for UIScrollView): http://developer.apple.com/library/ios/#releasenotes/General/RN-iOSSDK-6_0/index.html
The problem is the height setting. You somehow have to try to delete it. If you have added other constraints that are "sufficient", it should become deletable.
At the moment you have one user constraint for the height that is "Greater or equal" and an "Equals" constraint as well. Clearly, those are not working well together.
Maybe there is a conceptual error as well. The lower image view should not be fixed in position, so the distance to the lower image view will not be a "sufficient" constraint to let you delete the fixed height.
I think it should work if
the lower image view has a fixed height and
a fixed distance to the text view above, and
the text view has a minimum height as well as
a fixed distance to the image view above
(which should be fixed in relation to the superview).