The bottom part contains the Objects library available for Interface Builder. The Library window is where you can find all the UI elements that you may want to add to your program. You can start exploring the library by selecting the submenu under the Objects drop-down menu. Interface Builder is one of the most important editors within Xcode 4, so you may want to spend more time digging out the features under each tab and objects. It will definitely make your future design much smoother.
Taking a closer look under the MainWindow. Interface objects are the objects that are created when the nib file is loaded. Placeholders refer to files that live outside the nib file but are connected to the contents of the nib file. The First Responder placeholder object represents the first object in the responder chain, which is determined dynamically at runtime by the UIKit frameworks.
A default MainWindow. The window object is the one real object you can see on the Canvas here; you can play with it in the Editor pane on the Canvas. The Canvas in the center shows what the. In any case, this is where you arrange your user interface elements as you create them. In order for Interface Builder-created objects to be useful, Xcode must be able to access their properties and respond to actions sent to them. You saw an IBOutlet in listing 3.
You declare a method in your class, including IBAction as its return:. You can follow the step-by-step instructions to get familiar with the new tool. To give you a preview of the result, figure 3.
When the prompt for the project name appears, enter AppleStock and your company or your own name as the project identifier. This implies that the value of the notes property needs to be set during initialization and that it cannot be modified once it's set. That is one of the advantages of using initializer injection. The compiler throws an error. We can fix the error by defining a designated initializer for the RootViewController class that accepts an array of Note instances.
We assign the value of the notes parameter to the notes property. Once every stored property has a valid value, we can invoke the designated initializer of the superclass, init nibName:bundle:.
The compiler doesn't agree with the changes we made. It throws another error. It notifies us that we need to implement a required initializer of the UIViewController class, init coder:.
If we click the error, Xcode offers a solution. Click the "Fix" button to see what solution Xcode has in store for us. Because we defined a designated initializer, we are required to override the required initializers of the superclass, that is, the UIViewController class. You may be wondering why Xcode adds an implementation of the init coder: method in which a fatal error is thrown. That sounds like asking for trouble. To understand why Xcode offers this solution, we need to modify the implementation.
Let's remove the fatal error and invoke the implementation of the superclass. This introduces another problem, though. While this may appear to be a viable solution, it isn't. The compiler notifies us that the notes property doesn't have a valid value before we invoke the init coder: method of the superclass. How do we set the value of the notes property? We can't pass a value for the notes property to the initializer because we need to implement the designated initializer as it's defined by the superclass.
The answer is "We don't. We won't be using the init coder: method and, if we want to use initializer injection, the only option we have is throwing a fatal error in the initializer. In storyboard files, the top level items in the outline view correspond to top level view controllers, or scenes, on the canvas. Storyboard files do not show an icon view when the outline view is hidden. Each scene on the storyboard has a dock that shows a high-level object view as shown below.
Starting from the left, the items in the icon view correspond to the scene, the first responder in the scene, and the exit segue for that scene. You can add your own views to the scene dock in addition to those you add to the body of the view controller. For more information on scenes, see Designing with Storyboards. Select the Object library from the library pane by clicking the Object button in the library bar. Views dragged into the dock are only opened by segues or by API calls when the app is running.
The screenshot shows dragging a view controller onto the canvas. All of the other. For my case, I have multiple project with some other dependencies. I tried to solve it by deleting derived data or restarting XCode but it couldn't work.
In the end, I tried the following method and it works:. Set this for all projects in the workspace and recompile to make sure there is no other errors. Maybe not making sense but somehow did it. During my compilation, I had other issues such as linker errors and symbols not found.
Using Swift, I had a similar problem. I found out that the comments were part of the problem for me. I leveraged the default view controller, did some work in it, then created a second view controller by copying the entire first one, stripping it down to only viewDidLoad and renaming the class to TestViewController.
Builds worked, code executed. All was good. I noticed that my comments still said "ViewController. I was able to connect my outlet! I wonder if what occurred is that the Indexer was reading the comments as well as the class names, and somehow got confused.
I just had to delete the derived data folder. The new class not being part of the "TARGET" is likely the root cause of this, as alluded to by some of these answers. When creating a new cocoa class, by default the option to add new class to target is by default checked, but should, for any reason, this not be checked when you hit save, you will have this issue. Any of these workarounds that add the new class to the apps target will work to resolve the problem, and is something that all these 'fixes' have in common.
I think XCode likely has some bugs that causes a new file to, by default, NOT be added to the apps main target. In XCode 7. The error I was getting referred to one of my variables as if it were a class didn't make any sense. The error stopped occurring when I added the connector below that variable instead of above it. There is also a diferent reason for the issue The solution would be to delete it and re create it with right template.
I have to force it to load by clicking on Automatic and selecting the file.
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