I have a UITableView which has static cells, inside one of those cells is a UISegmentedControl. I've hooked up and IBOutlet to the control itself to the containing table view controller class. However, when I break in ViewDidLoad, the outlet isn't even set, it's nil. All other IBOutlets in that class are being set except for the UISegmentedControl.
Is this a bug? Has anyone else experienced this?
Thanks
Omg, this was all to do with localization. It seems after turning on localization none of my storyboard changes were being honored. I had to remove base localization and then re-add the storyboard to the project to fix this.
I hope this helps somebody else who may end up in the same situation.
Regardless of whether Auto Layout is on, when trying to change the UIImageView inside my Prototype Cell, the ImageView appears to move to a different position as you can see in the design below.
IB Design:
Simulator:
I have added Constraints and set them all to 'Required' and even tried deleting the other content in the Prototype Cell, but this doesn't work either.
What could I be doing wrong?
Edit
When I log my constraints, they seem to just be the width and height of the UIImageView
2012-12-02 15:49:30.313 myApp[7551:c07] Constraints - (
"<NSLayoutConstraint:0x80985c0 V:[UIImageView:0x80982d0(80)]>",
"<NSLayoutConstraint:0x8098600 H:[UIImageView:0x80982d0(160)]>"
)
Edit 2
When deleting the UIImageView altogether, it still produces the same output, i.e. the image in the same position.
Ok, so it turn out UITableViewCell already has a UIImageView named "imageView" and changing my IBOutlet to something less generic solved the problem.
Be sure to check the names don't already exist in the UITableView subclass!
I have a view that needs to have its frame manipulated programmatically - it's a kind of document view that wraps to its content which is then scrolled and zoomed around a superview by manipulating the frame origin. Autolayout fights with this at runtime.
Disabling autolayout completely seems a bit harsh because it could reasonably be used to handle layout for the other views. It seems like what I might want is some kind of "null constraint".
I had the same problem. But I have resolved it.
Yes, you can disable auto layout at runtime for a specific UIView, instead of disabling it for the whole xib or storyboard which is set by default in Xcode 4.3 and later.
Set translatesAutoresizingMaskIntoConstraints to YES, before you set the frame of your subview:
self.exampleView.translatesAutoresizingMaskIntoConstraints = YES;
self.exampleView.frame = CGRectMake(20, 20, 50, 50);
I had a similar issue where Autolayout was overriding some of my frame-setting at run time (I had a dynamic view that in some cases pushed a new view controller...pushing and then pressing Back would reset the initial view).
I got around this by putting my manipulation code in viewDidLayoutSubviews of my View Controller. This seems to get called after whatever constraint mojo gets called, but before viewDidAppear, so the user is none the wiser.
Perhaps just setting translatesAutoresizingMaskIntoConstraints to YES (and not adding additional constraints affecting that view) will let you set the frame without fighting the auto layout system.
In iOS 8 you can set an NSLayoutConstraint to be active or not. So if I'm using interface builder, I add all my constraints to an OutletCollection and then activate or deactivate using:
NSLayoutConstraint.deactivateConstraints(self.landscapeConstraintsPad)
NSLayoutConstraint.activateConstraints(self.portraitConstraintsPad)
The particular application I'm using it for here is having different constraints in portrait and landscape mode and I activate/deactivate based on the rotation of the device. It means I can create some complex layout changes all in interface builder for both orientations, and still use auto layout without the verbose auto layout code.
Or you can activate / deactivate using removeConstraints and addConstraints.
I don't know if this will help anyone else, but I wrote a category to make this convenient because I find myself doing this a lot.
UIView+DisableAutolayoutTemporarily.h
#import <UIKit/UIKit.h>
#interface UIView (DisableAutolayoutTemporarily)
// the view as a parameter is a convenience so we don't have to always
// guard against strong-reference cycles
- (void)resizeWithBlock:(void (^)(UIView *view))block;
#end
UIView+DisableAutolayoutTemporarily.m
#import "UIView+DisableAutoResizeTemporarily.h"
#implementation UIView (DisableAutoResizeTemporarily)
- (void)resizeWithBlock:(void (^)(UIView * view))block
{
UIView *superview = self.superview;
[self removeFromSuperview];
[self setTranslatesAutoresizingMaskIntoConstraints:YES];
__weak UIView *weakSelf = self;
block(weakSelf);
[superview addSubview:self];
}
#end
I use it like this:
[cell.argumentLabel resizeWithBlock:^(UIView *view) {
[view setFrame:frame];
}];
Hope it helps.
You can set the translatesAutoresizingMaskIntoConstraints type Boolean, Value Yes in the User Defined Runtime Attributes of the UIView you want in the xib/storyboard.
In my view I had a Label and a Text. The label had pan gesture. The label moves around fine during drag. But when I use the text box keyboard, the label resets its position to the original location defined in auto layout. The issue got resolved when I added the following in swift for the label. I added this in viewWillAppear but it can be added pretty much anywhere you have access to the target field.
self.captionUILabel.translatesAutoresizingMaskIntoConstraints = true
Open project in 4.5
Select storyboard
Open the file inspector
Under Interface Builder Document uncheck 'Use Autolayout'
You can split across multiple storyboards if you want to use autolayout for some views.
For me it worked to create the subview programmatically, in my case the auto layout was messing with a view that I needed to rotate around its center but once I created this view programmatically it worked.
I've encountered a similar scenario, where I joined a project that was initiated with auto-layout, but I needed to make dynamic adjustments to several views. Here is what has worked for me:
Do NOT have views or components laid out in interface builder.
Add your views purely programmatically starting with alloc/init and setting their frames appropriately.
Done.
This happened to me in a project without storyboards or xib files. All 100% code. I had an ad banner at the bottom and wanted the view bounds to stop at the ad banner. The view would resize itself automatically after loading. I tried every resolution on this page but none of them worked.
I ended up just creating a sub view with the shortened height and placed that in into the main view of the controller. Then all my content went inside the sub view. That solved the problem very easily without doing anything that felt like it was going against the grain.
I am thinking if you want a view that is not the normal size that fills the window then you should use a sub view for that.
Instead of disabling autolayout, I would just calculate the new constraint with the frame you are replacing. That appears to me to be the appropriate way. If you are adjusting components that rely on constraints, adjust them accordingly.
For example, if you have a vertical constraint of 0 between two views (myView and otherView), and you have a pan gesture or something that adjusts the height of myView then you can recalculate the constraint with the adjusted values.
self.verticalConstraint.constant = newMyViewYOriginValue - (self.otherView.frame.origin.y + self.otherView.frame.size.height);
[self.myView needsUpdateConstraints];
For those of you who are using auto layout, please check out my solution here. You should be making #IBOutlet's of the constraints you want to adjust and then change their constants.
if it's xib file:
select the .xib file
select the "File's Owner"
show the Utilities
click on: "File Inspector"
Under "Interface Builder Document" disable: "Use Autolayout"
So I'm just trying to create a very simple app for demo purposes here:
Created a Single View Application, using storyboards
Added a UIView to the storyboard
Added the following code to my controller's header file:
#property (weak, nonatomic) IBOutlet UIView *myView;
Now, I understand that I can link the UIView to the controller by:
arranging my code such that the header file is next to the storyboard
holding down Ctrl key and dragging it to the property in the header file
My question is this: can I do this without Ctrl-drag? And if so, how?
More specifically - it's annoying to have to put both my header file and storyboard on screen at the same time, and it seems there should be a way to make this connection without doing so.
I also understand that I can manually place the view by creating it inside my controller's viewDidLoad function, but I'd really like to use the interface builder to simplify / visualize things.
Edit: Is the answer to my question affected whether I use storyboards or xib/nib files? (I'd switch to use the one where it works)
you should be able to right click the element, and drag the "referencing outlet" item to the view's "File's Owner" in interface builder. There, it will give you a list of all available IBOutlets (matching the object's type).
In addition to Dima's answer, you can just as well use the Connection inspector in the Utilities pane
I just created a new Xcode project. In the AppControl class Header file I have the following objects defined (and some other ones, too):
IBOutlet NSImageView *inputImageView;
IBOutlet NSImageView *outputImageView;
IBOutlet NSTextField *myNoiseLevel;
IBOutlet CGFloat *mySharpness;
After putting the basic code into the .h and .m files, I then went into Interface Builder and created my UI. I was able to bind the two NSImageView controls in IB to the corresponding NSImageView objects listed above. And I was able to bind a couple of other objects/controls, also. But I am NOT able to bind the last two items listed (myNoiseLevel and mySharpness) to the NSSlider controls I have on the application main window. I'm not sure why. I know this kind of thing is probably hard to diagnose, because it is not "strictly code related," but if there is something "tricky" about binding sliders please let me know what the main "suspects" are that I should check.
This is my first attempt to use a slider control through IB. I have a book (Cocoa programming for Mac OS X, 3rd ed., by A. Hillegass) that I am using to learn about the basic way to do this stuff. And he has a slider example in there. But his slider example is "continuous" and it uses key path binding. I think this is overkill for what I want/need to do -- I just want to pull the value from the slider when another button is pushed (no need for "continuous" update). So I am trying to directly bind the "outlets" listed when I right-click on my App Control object (one for each of those items shown above), to the slider controls on my window. But when I cntl-drag from the AppControl outlet up to the corresponding slider, the slider will not "accept" the arrow I'm dragging.
Does this make sense? Any idea what I'm doing wrong and/or what I need to do to make the binding work? I have tried saving / building / closing & reopening IB and Xcode -- all to make sure IB has the latest version of everything. Still no luck, though.
One last thing ... What I really need are CGFloat numbers, from the slider. Can I simply declare the Outlet as CGFloat type ... or do I need to define it as NSTextField (or something else), and then convert it to Float in my program? You can see in the IBOutlets I pasted above, that I was trying different data types for the outlets (trying to see if my defining them as CGFloat was somehow preventing the bindings).
Make the outlet an NSSlider*. You should then be able to connect to it. When you need the value (eg, in response to the button press you mention) call [yourSliderOutletName doubleValue].
More generally: an IBOutlet is an ivar that can be filled in with a pointer to the actual object awoken from a NIB file. As such, it needs to be of an appropriate type to hold that pointer -- the object's actual class, or one of its superclasses or protocols, or (least informatively) id. You can't just arbitrarily connect an object to any old variable, like your CGFloat. There's no implicit conversion -- how is the system supposed to know what you want?