I am trying to develop a simple app with one screen for iOS and am running into a strange problem. Only half of the app is showing up. For example I have a screen with just one button in the center of the screen. When I run the app in the simulator I only see half the button and I cannot move it either.I can scroll the view in the simulator vertically but not horizontally. I am stumped. Will appreciate any pointers.
I'm pretty sure you built your view using the main storyboard and put everything in the middle of it. The main storyboard is set to take all iOS format into account, iPhone and iPad. If you want your app to appear centered on your iOS device, you need to constraint the position of your different UI objects, using Auto Layout. That way it would appear centered automatically, whatever is the device you're using
I reckon you've got AutoLayout turned on... but haven't set any constraints on your controls yet.
Try the following test:
Go into your Storyboard file.
Click on a blank area in your storyboard, then on your screen (so the border of your screen is blue - not black or gray).
In the menu bar, click on Editor \ Resolve Auto Layout Issues, and then "Update Frames".
Alternatively, you can click on the following button, and select "Update Frames" from there (it doesn't matter which one):
When you do this, where does your "one button" end up ? Does it suddenly disappear off the screen, have a negative X or Y position, or a width/height of 0 ? If so, then AutoLayout is your problem.
With XCode 6.1, Apple has put a gun to developers' heads and demanded that when you add an object to a Storyboard, you must - straightaway - add some constraints to it.
I had this issue when I first upgraded to XCode 6.
I would add, say, a View to a screen, stretch it to a particular size, then drag a second control (perhaps a Label) onto the same screen. Suddenly, my View would resize itself to a height/width of zero, or be positioned way off the side of the screen... huh ?!
To get around this, when you add a control onto a Storyboard, you must add sufficient constraints to really let XCode calculate where to position it, based on which device/orientation the device is running on. And, yes, you sometimes need to do this straightaway before XCode ridiculously decides to mess up your control's position or size.
I really do loathe XCode. This isn't the way a development environment should behave in 2015...
If I get your point of problem then
I m sure the problem is you have auto layout and size classes enabled.
check if you have Auto layout and size classes enabled ....???
If yes then you haven't set the constraints accurately. set the constraints for the UI Objects to show on your desired position in screen.
Related
I used to be able to do this:
UIButton *bigBottomBtn=[[UIButton alloc]initWithFrame:CGRectMake(0, self.view.frame.size.height-60, self.view.frame.size.width, 60)];
I also used to be able to just drag a button onto a storyboard and add a constraint that would hold it to the bottom of the parent.
What is going on with Xcode, Autolayout and Apple for that matter....is my Xcode not working properly? Have I missed a major memo? is Apple just going downhill fast?
Your button-creating code used to work (and still does) if self.view's frame was correct at the time you created the button. Note that the view doesn't necessarily come out of the xib or storyboard with the correct frame; the xib/storyboard contains the view at some design size which might not match the current device. This wasn't as much of a problem when all iPhones had 3.5 inch screens, but became a pretty common problem with the advent of the iPhone 5's 4 inch screen.
The view isn't guaranteed to have its correct frame until its superview's layoutSubviews returns, so if for example you're creating bigBottomBtn in viewDidLoad, that's too early. Many questions on stackoverflow cover this problem. You either need to set the autoresizingMask of the button, or implement layoutSubviews or viewDidLayoutSubviews to update the button's frame, or turn off translatesAutoresizingMaskIntoConstraints and install constraints. Note too that your view can change size if you support rotation, slide over or split view multitasking, or if your view can be the detail view of a UISplitViewController, so it's a bad idea to try to guess the correct frame of the button based on the device's screen size at the moment the button is created.
Note that storyboards now by default use a design size of 600x600, which isn't the size of any device. This is probably because if Apple chose some device's size (say, the iPhone 5's 320x568) as the default, and you happened to use a device of that size as your primary (or only) test device, you could easily forget to think about what your app will look like at other sizes. However, you can explicitly set the design size to some device's size if you want:
I usually use “iPhone 3.5-inch” if I don't specifically need something bigger, because it lets me get the most scenes on the screen simultaneously (and produces the smallest screen shots for stackoverflow).
As for “I also used to be able to just drag a button onto a storyboard and add a constraint that would hold it to the bottom of the parent”, I have good news: you still can. Example:
However, you do need to be careful if you have filled your root view with a table view as appears to be the case in your screen shots. You need to drag the button to the document outline in that case, because if you drop it on the table view, Xcode will assume you want it to be the table view header:
Trying to pin a table view header to the bottom of the screen would be folly.
As for the Editor > Align menu, I have found that the items can be mysteriously inactive, which is frustrating.
Note, though, that only the “Horizontally in Container” and “Vertically in Container” will work (when they work at all) with a single view selected. To use the other items in the menu, you need to have at least two views selected, because the other items align the selected views with each other by setting their frames:
If you only have one view selected, Xcode doesn't know what other view you might want to align it to.
Those menu items are perhaps useful in the springs'n'struts model, but they don't add constraints, and under autolayout you probably want constraints to enforce the alignment at run time.
As far as I know, those menu items have never added constraints, but I'm not going to reinstall Xcode 6 to verify that, because there's a convenient popover that will add constraints corresponding to all of those menu items:
In xcode you always need to add buttons according to its visibility. As you said you need to show button on top of tableView and it should be aligned to bottom. For that You just need to arrange the order of items. as shown in the image below.Provide the layout for the button.
I would really appreciate if someone can tell me about how can I use one xib file to target different device sizes. I am creating a Custom Keyboard extension using a xib file having view property of "freedom". The view loads great in iPhone 4,4s,5 and 5s. However whenever i run the app for iPhone6 or 6s there is a blank space at the right hand side. (please see the attached screenshot, missing area is shown in red), looks like the keyboard doesn't stretch according to the screen size.
How can i fix that? I disabled the auto layout and use size classed option. I am a very new developer and coding using swift.
Thanks a lot
I would use autolayout for this, I would not disable it in the xib. Its also the reason as to why you have a space at the end of your view, as it is not expanding automatically to the sides, it has been set statically e.g. setting the frame.
I would have a look at this link but in the mean time I would re-enable autolayout then with your keyboard view container ctrl click drag to your main view and select Leading(left), Trailing(right), Top & Bottom Space to Container. Below is the popup menu from ctrl clicking then select the triangle at the bottom right then Update Frames, this will relayout the view. It might not layout the keyboard keys correctly but its is a start.
I am using XCode 6 to make a simple calculator using Swift. Anyway, I compiled the code with the initial GUI and it works. However when I change the positioning of some buttons, it does not show up in the compiled app running on iOS simulator. Does anyone know what should be done?
Also, I've changed the code as well, and the code is updated. Ie, pressing button 1 will show 1 in the main textbox, but the interesting thing is the position of the button, which I have changed, still remains in the same position I set it to be initially.
How are you changing the positions of the buttons? If you're doing this by setting frames in code, and your original GUI is laid out in a storyboard, then you're probably fighting against auto layout.
Your storyboard layout will be driven by constraints, which determine the size and position of all the elements of your GUI. Setting a frame manually doesn't change these constraints, so the layout engine resets everything.
Either turn off auto layout (bad idea, since you now have to cope with every screen size manually) or move your buttons by adjusting your constraints.
I have a UILabel that i placed in the top left corner of the screen in the Storyboards. I disabled "Autolayout" and it works perfectly fine on the iPhone 5 screen. The problem comes when i try them on any of the smaller screens like the iPhone 4. The label is then placed on the bottom right corner. After this issue, i tried to programmatically 'fix' the position in the "viewDidLoad" method of the view controller, but it stills moves position and the problem continues.
Ive been scratching my head about this for a while!
Any help would be appreciated.
I would suggest that you turn autolayout back on. If you get the constraints right, this situation (two different screen sizes) is exactly the sort of thing autolayout is really good for. There's a very good reason why Apple migrated autolayout from OS X to iOS at exactly the moment the iPhone 5 screen appeared on the scene!
try to fix it at viewWillAppear
Go to the utilities panel, click the tab "Show size inspector", and change the autosizing. Then drag your component in your storyboard's view so that it stays in one of the "borders". If you do not need to support older iOS versions, I'd recommend you to figure the proper way with auto-layout though.
I am having a strange situation. I created a very simple screen with some buttons on the storyboard, then when I ran the emulator (is it correct to say simulator or emulator?) it got the spacing wrong for one of the buttons.
I am adding a screenshot. The emulator is to the right of the storyboard screen.
Any idea why this may happen?
I thought it was a problem with the button. And it might have been. But when I took out two lower buttons, I got something even weirder as shown on this screenshot:
Thanks!
It looks like you are using Autolayout, and all your buttons except Investment has a Top constraint while Investment has a Bottom constraint, causing Investment's distance to bottom to stay the same when the screen grows taller.
Click on Investment button, click [Editor -> Pin -> Top space to Superview] in the top menu.
Click Investment button again. Click the second tab from the right in the right panel (the one where you can set frame). Look for a Top Space to Superview constraint, right click and delete. If there isn't one, then XCode did its job. Try running simulator again.
Edit: I just want to say that XCode has a habit of adding Top constraints for you when the view you just dragged into the xib is in the upper half of its container, and Bottom constraints when it's in the bottom half. I know XCode is trying to help but it drives me crazy sometimes.
It looks like you're using a 3.5" simulator and laying out for a 4" device, so the view will be resized.
If you're using autoresize masks, are some of the autoresize masks on your buttons incorrect? You probably want them all to stick to the top of the screen. Check to make sure the autosizing for each of your buttons matches this image. (You'll need to click the "ruler" icon to see these settings.)
I assume that you're using the XCode4 which provides NSAutoLayout as default. When you place an object to the storyboard NSAutolayout automatically creates constrains which layouts the object on the screen automatically for different devices(iPhone4,iPhone5) or orientations(portrait/landscape). Please check NSAutolayout class and constrains. if you want you can remove the NSAutolayout and your objects will be displayed on the simulator normal but in that case you have to manually adjust your objects for different orientations and screens
Hope helps.