(XCode Autolayout) Label/Button position&size keep changing over time - ios

Hi I'm new to Xcode and I have been checking out ObjC tutorials lately and I started playing around with the storyboard.
So What I did was:
Drag some buttons/labels onto a view in storyboard
Set the size & position using the size inspector
Build and preview the app on the iPad
It looked fine at the beginning, but then I noticed that the position and size of the buttons/labels kept changing over time (by like a few pixels) as I built the project for a number of times.
I have not change (or set) anything about insets/constraints yet.
Can anyone please advise as I dont think anyone would be happy for changing the position & size when there is over 100+ UI elements.

The thing is that you have created the layout for one pixel density and implement on different pixel density. Which means you to exactly see what you are making build the layout in also ipad (you can change it in the storyboard see below).

Related

Manually adjusting positions of UI elements in Xcode's storyboard

Instead of having to use xcodes constraints, which I can never get to work right, is there a way to manually set where UI elements are on the screen? I noticed that if I'm on the attributes bar for the view controller, I can set simulated metrics's size to any iphone size I want.
Then I can position the UI elements on the screen where I please. When I build and run, it always mimics exactly what I set up. However, it only works for the particular size of the iphone I specified. Is there a way to do all the sizes manually without making several xcode projects?
Thanks!
There is multiple other solution that is not as good as constraints.
1) Use frame property of views to place them
2) Use size classes to do different placement for iPad iPhone etc
3) Use suggested constraints - you are placing views and than you can give XCode possibility to create constraints for you suggesting what you want from your views placement.
You're going to want to learn how to properly use constraints. The approach you're trying to do would have been okay when there was only one screen size, but now we have three different sizes of iPad, two watch sizes and four different iPhone sizes. Here's a link to a tutorial from Ray Wenderlich (he has some pretty good tutorials to get you started n a wide variety of things). https://www.raywenderlich.com/115440/auto-layout-tutorial-in-ios-9-part-1-getting-started-2
The auto layout in storyboard on Xcode 7 isn't my favorite, but when Xcode 8 comes out it provides device specific sizes for views that makes auto layout much easier. So maybe Xcode 8 will provide a better solution to your problem!

App not displaying properly on iphone6

I am having an issue with running my project on the device. Here are two pictures. The first one shows what the project looks like when I run it on the simulator. The second one is the same project run on the device:
As you can see in the first screenshot, I am using Auto Layout and Size classes. On the attributes Inspector I have the size set to iPhone 4.7-inch, but if I set to to "inferred" the same thing happens. I have done a fair bit of research on the web to see if I can find the solution but to no avail. I am fairly new so it could be something simple. Any help appreciated.
Update: I have set the size to inferred and turned off size classes and auto layout and I had resize all the buttons from 100 pixels to 80 pixels and now it looks fine on the device but I get the opposite problem on the simulator which was fine then. Is this an issue to do with iPhone 6 plus?
See next screenshot. On the left the storyboard and on the right the simulator.
Have you set attribute for it..? Because you are using size class.
Check it. If not set then set it for all objects.

Why is iOS simulator displaying blank screen when I rotate device?

Getting through some introductory swift and playing with Xcode and I basically just have a page with some color squares, background color etc. Doesn't do anything. Problem is when I compile the code it will run in simulator just fine and show everything perfect, BUT when I rotate the device, everything disappears and it only gives me a blank white screen. Rotating right or left does it. The only view that shows it is the original upright view (for all iPhone devices that I tested on through the simulator).
Xcode 6.1.1 and iOS Simulator 8.1 are being used on my MacBook Air with OSX 10.9.5.
In the App general page, I have already checked under Deployment info that Landscape Right and Left are both checked on. Storyboard is set on Any H and Any W.
I'm not sure what I'm doing wrong and it has been pretty difficult searching since I'm still new to iOS development I'm not sure I'm using the right words or whatever because I can't find an answer.
Summary:
App displays properly in iOS Simulator, Portrait View but no other views work and will display blank white screen instead.
In order to see if your views are actually being drawn and just off screen as others have suggested capture the view hierarchy. Go to 'debug' in the menu, then in 'view debugging' click capture view hierarchy. This will pause your app and create a 3D representation of all view on your screen which you can move around by clicking and dragging.
Are your views actually being drawn? If yes are they drawing off screen? If yes then you need to fix your constraints.
It sounds like you haven't set your constraints appropriately. Try setting the top and leading constraints for each of your views to something less than 320 (should cover all device sizes). Fix your warnings, then try again. I believe the views are simply off the screen.
You don't have the correct auto-layout UIConstraints set in interface builder. Check the document outline view in interface builder and ensure that you have appropriate constraints set on each view.
Auto Layout issues occur when you create conflicting constraints, when you don’t provide enough constraints, or when the final layout contains a set of constraints that are ambiguous.
Check this Apple documentation out, it will show you step by step how to resolve your (common) issue.

Using a launch screen (.xib) stops scaling

It's my understanding that apps for iOS 8 should have a storyboard file as launch screen rather than an image. I've created a really simple launch screen file that has any width and any height, and has one label of plain text reading "placeholder" and set it as my launch screen. However, when I try to run my app on the iPhone 6 and 6 Plus simulators, there's black bars around the background and the buttons on the main menu are out of place. The problem doesn't seem to be present in the 5s or iPad. Most of my assets aren't optimized for the 6 and 6 Plus though, since they were created before they came out. Is that why this is happening? Or is it something else? Thanks in advance.
Edit: Apparently, putting in a launch screen stops the app from automatically scaling. Is there a way to have both a launch screen, and keep the app scaling? Or do I need to make new assets?
This is a bit of an old question, and I ended up using a launch image instead of a launch screen, but you can probably solve this by using constraints. If you set top, bottom, leading, and/or trailing constraints on an item in the view, it'll scale itself to fit those constraints (if possible). For text, it has the autoshrink property which you can change to minimum font scale (instead of fixed font size), though I'm not sure how you can scale text up. The autolayout documentation is here.
To create a launch screen from a xib file first create a new file from under “User Interface” and select the option called “Launch Screen”
Using autolayout, design the first view of you app so it scales to suit all resolutions that your app supports.
Using the new Launch Screen
Under the app setting select the newly created Launch Screen from the app options.
This is the example for using a xib file. It can also be done using storyboard as shown in Ole Begemann blog

UITextfield Custom Position moved up because of different iPhone sizes

I have several custom UITextfields in my app. I started this app on Xcode 5 and ran on iphone 5 simulator. After Xcode updated to Xcode 6, I ran the app on iPhone 6 simulator. Now all the textfield positions moved up because of large screen size. I just wanted to know is there anything I could do so that the positions of textfields automatically get adjusted depending upon the iPhone models.
You need to rebuild your interface to handle the different screen sizes. In particular, you need to work with the AutoLayout feature to help determine how you want everything to scale/move/position based on multiple screen sizes. This can be done via the Storyboard (easier but sometimes frustrating) or in code (harder at first but more control later). I usually use Storyboards and it's worked great on several projects.
Do you want it centered and respecting your original layout and margins? a certain distance from the top or sides? everything scaled up appropriately? All these things can be done with AutoLayouts.
Check out the great tutorial here for more information:
http://www.raywenderlich.com/50317/beginning-auto-layout-tutorial-in-ios-7-part-1

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