16 pixels margin left and right on UIView created with autolayout - ios

I use autolayouts not for a long time and they often confuse me.
I have a wired constraints behaviour. I want to create a red view and make its margins 1/1/1/1. I tap a corresponded icon in the storyboard and set all fourth constraints to 1.
First of all values for left and right constraints are -16 and it's very strange. I have no idea where Xcode takes them.
I set all constraints to 1 and run my application. On the screen I see the view with top and bottom margins equal to 1 and right and left equal to 15.
And I have this behaviour always in every project. It very confuses me and don't give make UI correctly.
Does anybody know how can I avoid it? Everything I need it's say "Hey, Xcode, set margins for this view to 1/1/1/1" and the visible result will be the view with margins 1/1/1/1.

As usual, just after posing a question I've found a solution. When you set constrains turn the "Constrain to margins" checkbox off.

Related

How to center TextField using Xcode constraints?

I am new to iOS and am trying to align these TextFields in iOS. Below is how I would like it to look on an iPhone 7.
However, on the iPhone 7 Plus, the TextField shifts to the left of the center, despite my constraints.
Why is this? I have a constraint that aligns them to the Center, as seen on the right part of the screenshot.
It is very simple!! Just follow below steps,
Open you .xib or .storyboard file
Select view you have to add constraint
Click on align button at the right - bottom corner
Set horizontally in container constraint 0
Then press add constraints button
You can add any constraints to any view by following these steps
You just have to seth trailing and leading space fixed means both left
and right indicators should be red as shown in the screenshot.
For more details see the screenshots:
It will remain fixed from left and right in all the screens.
in your case is important set the width constraint.
However you can use trailing and leading constraints, in this way you will not need to set a defined width for your textfield and the position is correct for all type of devices.
If you want design like this so you have to take UITableview then take UITextfield for every cell beacuse you use every cell as view so easily manage all textfield and constraint. And also easily scrolling if device is display small.

Swift - Why ScrollView not full screen?

I had inserted a ScrollView into UIViewController and dragged ScrollView to fill the space between the navigation bar and the RAM label below:
But when I run the app, the ScrollView does not fill the space:
Please help me! Thank you very much.
P/S: Sorry for my english is bad.
The scroll view is not covering up the whole thing because you are running the app on a much bigger phone. The simplest solution is to run the app on iPhone 5.
However, if you want to solve the problem on all sizes of iOS device, you need to add constraints.
Constraints are things that tells a view when and how much it should resize and where it should be positioned.
To add a constraint, just select the view you wish to add a constraint to and go to the bottom right corner. You will see 4 buttons:
The leftmost button is used to embedding views in stack views. This is a feature of iOS 9. If your deployment target is lower, just ignore it.
The second button to the left is for adding constraints related to alignment - where the edges of the views are, what its baseline is and where it is positioned in the X and Y axes:
The third button to the left is used to add constraint related to margins, width, height and how the width and height should change when it is asked to resize (keep the aspect ratio, for example):
The rightmost button is used to let Xcode decide what constraints you should add. And I think most of the times its choices are okay. Sometimes though, you still need to do some tweaking before it works.
"So... what constraints should I add?" you asked.
Well, I think I should teach you how to think when you want to add a constraint. This way, you can figure it out yourself in the future.
You should first let Xcode guess what constraints you want. Just click the rightmost button and click "Reset to Suggested Constraints". This can save a lot of work if Xcode can get it right. So remember to always do this first.
Then, run your app on various devices and see if the view's position, size, and alignment are as you expected. If it is not, you might have to add and/or remove some constraints.
For example, if you found that your view is always the same size on different devices, (that could be bad because it means that some content my go out of view on smaller devices) it's probably because Xcode added a width and/or height constraint to the view. You should delete that so that the view's width and/or height is not fixed.
You can find your view's constraints in the view hierarchy:
Just select the constraint and press delete.
Uncheck Adjust subview option and add
scrollview.view.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
You need to add constraints for your scrollView. Set the leading and trailing constraints to 0. Pin the height of your scrollView and also don't forget to set the top layout constraint. You can either pin the height or add bottom layout constraint to your page control.
Constraints are very important and its even more important to set it correctly. Check the Apple Documentation - Working with constraints in IB
Uncheck constrain to margins and add 0 every one of the four limits of spacing to nearest neighbour.
My guess (from the little information we have) is that you are creating a constraint from your scrollview to the top of your view with a value equal to the height of the navigation bar. Set the value of this constraint to 0.
Just set the 4 constraints to 0 to the area you need and then uncheck the "Content Layout Guides" checkbox in the constraints tab here. It will automatically adjust to the area you have specified.
The checkbox to uncheck

Auto height setting for labels in iOS

I have previously worked in Windows phone and see that every control in windows phone has an Auto property, meaning occupy the size of the content.
I see that in iOS such a property does not exist. When there are dynamic data to be bound to a UILabel, I always need to calculate the height of the data and then assign to the UILabel. This takes a good amount of time and bit painful. Is not there an Auto property or am I missing anything here?
iOS has AutoLayout which is really helpful, get familiar with it.
Click on the Label
Click on the pin constraints button (little square button)
Add your custom LEFT, RIGHT, TOP margins or LEFT, RIGHT, BOTTOM margins
Click on "Add 3 Constraints"
Set number of Lines to 0 which means as much lines as view needs
Then you probably got warning lines, but you can solve them
Just click on fix constraints button (little triangle button)
Click update frames
UPDATE
Important: the answer to your question is to PUT NUMBER OF LINES TO 0 you can use that UILabel with 0 lines(which is autosizing) with frames and AutoLayout. AutoLayout is just a friendly suggestion that can be helful to setup views. Also put Line Breaking Word Wrap
Here you go also with some useful links for working with AutoLayout. AutoLayout is great because you don't care anymore what size is the screen, what orientation has the device at that moment. You just need to setup everything correctly and everything works amazingly but if your setup is wrong then AutoLayout might become your enemy. So start learning and experiencing right now.
Very good point to Begin learning AutoLayout
If Your are being lazy, start from video tutorial series
Great iOS7+ table view tutorial with autoresizing cells
Also check out this Stack Overflow discussion
You need to familiarize yourself with Auto Layout:
Auto Layout dynamically calculates the size and position of all the
views in your view hierarchy, based on constraints placed on those
views.
Just give top, left and right constraints and make label's numberOfLines to 0. That's it. Label's height will resize automatically.

Two Buttons. Above each other. Over whole screen

I just like two buttons above each other with no margins. This seems like an easy task, but I am new to iOS and I wasted too much time now. I tried dozens of contraints but it never went out well. I always ended up with setting the leading Spaces to -24 and having marings above and beneath the buttons. I am using xcode6, iOS8.1 and storyboard. My app is landscape only. Can someone please teach me what to do?
The buttons should look like seen in this picture: Fullscreen, no margins and Button1 should reach unter the statusbar!
I'll outline the steps:
Pin Button 1 to 0 spacing on Left, Right, Top
Pin Button 2 to 0 spacing on Left, Right, Bottom
Select both buttons, then Pin heights equally
(You can access pin either from the Editor tool bar in the top menu, or from the second icon in the constraints area)
The thing with constraints and auto layout is that you only need enough constraints to let the app calculate where elements should be at all times. You might be able to get away with less constraints.
To get remove the borders, you need to change the button Type in IB from System to Custom, then you can drag and alter the margins to remove them. Following that you will need to update constraints on the buttons.

Autolayout - Why does "Vertical Spacing" sometimes attach to the opposite side of a view?

When I select "Vertical Spacing" in interface builder, I expect the bottom of the upper view and the top of the lower view to have a relationship. However, frequently what seems to happen is that the bottom of the lower view gets linked to the bottom of the upper view. Then at runtime the bottom view will have the wrong frame (after resizes, animations, etc.). Is there a way I can ensure that views are consistently linked bottom to top?
[EDIT]
Here's another example. I set a height of 419px. I select "Top space to top layout guide". But instead it puts a constraint for how far the bottom of the imageview should be from the top of the superview. Then I change the height from 419px to 374px, and the view has correct height, but a gap at the top.
I've noticed this many times (usually when attaching the top of something to the topLayoutGuide), and I've put it down to a bug in Interface Builder. It seems like the issue has gone away in the betas of Xcode 5.1
The only workaround I've found is to initially move your view away from the view you're attaching it to, and then create the constraint. In this situation, Xcode will usually do the right thing. Then manually edit the constraint's constant back to 0 (or whatever you want it to be).
Instead of adding vertical spacing, try by adding "Top spacing to nearest neighbor" constraint. Please refer attached image,
Hope this will help.
This issue is fixed in the latest versions of Xcode. You can now select which part of the constraint you want to attach to. It may attach wrong initially, but the constraint editing controls are much better now.

Resources