How can I look behind the scenes? For example I would like to know more about the isEqual function ... Command+Click -> Jump to Definition does not show how this function work.
let pi : Double = 3.14159265359
pi.isEqual(3.14159265359)
If the code is in a compiled framework, like Foundation or UIKit for example, Xcode will take you to the declaration of the function, where you'll be able to see the function signature and maybe some comments about it, but not the full code becase since the code has already been compiled, Xcode doesn't have access to it.
Swift is open source, you can go to the repository and see how it's implemented. I think this includes most of Foundation, but it won't include Apple's frameworks like UIKit, SwiftUI, etc.
Related
My project is in a Pod.
And I want to swiftify a CollectionViewCell (TVPromotionCollectionViewCell).
I just change the codes to Swift and added #import "MyProject-Swift.h" in the file which has the collectionview using TVPromotionCollectionViewCell.
But the 'MyProject-Swift.h' cannot find the BaseCollectionViewCell which is written by obj-C and I've not edited.
I read the solution of
Cannot find interface declaration in myproject-swift.h
But... I can not used the solution in my project.
In my Swift 2 project, targeting iOS 9.2 and above, in Xcode 8.2.1, I have code that shows the mail-compose screen like so:
if MFMailComposeViewController.canSendMail() {
let composeMailVC = MFMailComposeViewController()
composeMailVC.mailComposeDelegate = self
composeMailVC.setSubject("Test")
// etc
}
Originally I had a reference to the MessageUI.framework in my project properties, but after removing the framework reference and cleaning the project, it still builds fine and when I run the code on my device the mail compose window still appears and seems fully functional.
I cannot find any explicit references to MessageUI.framework in the raw text of my .xcodeproj file, nor is there anything in my Objective-C bridging header.
I know that Swift does make some implicit framework references, but I couldn't find anything that suggests MessageUI.framework is one of them.
Curiously when I jump to the definition of MFMailComposeViewController XCode shows it in the MessageUI module.
The compiler automatically added the frame work in given its previous direction - IE. Import.
I just have updated my Unity to 5.3.1 and it seems like EditorApplication class is already deprecated. The Unity suggests me to use instead the EditorSceneManager.OpenScene but looks like it's not returning of type bool anymore. Therefore causing my game to stop compiling.
Any help about this?
Thanks!
Usually due to deprecated code unity itself offers some changes in your code you can make a backup and try that if unity informs you of it ,but if you want to know if it has been loaded or not you can use its return value which is a struct of type Scene.
SceneManagement.Scene newScene = EditorSceneManager.OpenScene("myScene");
if(newScene.isLoaded) {
//do something
}
There is another method also named IsVaild You Can try that too.
further doc :
http://docs.unity3d.com/ScriptReference/SceneManagement.Scene.html
It's hard to help you without any information on what you actually want to do... This link may help though, it's about upgrading to Unity 5.3.
Pretty basic stuff but i am unable to troubleshoot where the problem is. In my project, i have a class named "TheFeedStore" with following two methods:
- (BOOL)hasItemBeenRead:(RSSItem *)item
{
............
}
- (void)markItemAsRead:(RSSItem *)item
{
.........
}
I am using the following class method so other classes can access these methods using it:
+ (TheFeedStore *) sharedStore
{
static TheFeedStore *feedStore = nil;
if (!feedStore) {
feedStore = [[TheFeedStore alloc] init];
}
return feedStore;
}
In one of my another class, i can easily access the above methods by writing
if ([[TheFeedStore sharedStore] hasItemBeenRead:item])
or
[[TheFeedStore sharedStore] markItemAsRead:entry];
But in another class if i try to access these methods in a similar manner, i get the error "No visible #interface for 'TheFeedStore' declares the selector 'hasItemBeenRead:"
1) I have imported TheFeedStore.h file in the classes from i am
accessing these methods of TheFeedStore class.
2) I have checked like 10 times and there is no typo.
3) The methods i am accessing are also declared in the header file of
TheFeedStore.h
UPDATE: Just to check, i have declared another test method in TheFeedStore.h, same result, one class can access the newly created method while rest of the three classes cannot.
UPDATE: I have tried creating more methods in the TheFeedStore.h just for troubleshooting this issue. The new methods are also not accessible from the other classes. But if the return type of these new methods is (RSSChannel*) which is another model class in my project, than they become accessible. If their return type is other than some class like (void) and (BOOL) then they are not accessible. Here is my TheFeedStore.h https://gist.github.com/jessicamoore112/5558473
You have said that you are using #class instead of #import in your header files, the methods that you are trying to access are declared in the header files and there are no typos of any kind.
In such cases, usually no body points this issue but i am going to do it anyway because i have faced such issues many times. You have probably created many copies of your project to work on each functionality and also keeping a working project.
When you do this, sometimes Xcode is still using the older copies of few files. That means it is still using the older copy of the TheFeedStore.h when the methods you are trying to access were not declared by you.
How to solve this problem is very simple. Go to the file from which you are trying to access the methods and the files in which these methods are declared.
In the Utilities section on the right hand side, check the location and full path under "Identity and Type" area.
First check the names of the project, if it is different from the project name that you are working on, that means Xcode is still pulling the old copies of the files from the previous revision of your project. See the blue arrows where the project name is 13SampleMoreRequests in my case.
If this name is same as your project name, then my answer does not solve your problem. If its different, you should use the new copies of the file by browsing the new location using the sign that is pointed out by red arrow.
Once you browse and use the new files, your problem will be solved and you will be able to access the methods. If you still can't, copy these files, delete from the project and then add them again and you won't face this problem.
Hope this helps!
Cyclical imports, e.g. A.h imports B.h while also B.h imports A.h is the most common problem.
In C, cyclical imports won't work and one of the imports will be silently ignored. Make sure you are not having a cyclical import. If you do, solve it (e.g. using forward declarations).
Import problems can be also easily inspected if you generate the preprocessed output (you can find it in one of the Xcode menus).
That might sound silly, but I have similar cases once in a while and sometimes just simple quitting and starting xcode helps, it tends to stuck sometimes.
Also, sometimes cleaning the project helps.
'Cause I have very similar to yours singleton code and it works fine.
Guys I had encountered the exact same issues. After some searching on SO and the search engine I was able to solve it.
In my Case I have four files:
RadioStation.h
RadioStation.m
ViewController.h
ViewController.m
My mistake was to place all my methods in RadioStation.m and only put my variables on radioStation.h
So when I import radioSation.h on my ViewController.m and try to define methods for button-click on my app that's where the problems started.
I got the error/warnings "ARC Semantic Issue: No visible #interface for Class declares the selector" every time I built or ran the app simulator.
My Solution was to go back to RadioStation.h file and just declare all my methods there.
Since they were already defined on RadioStation.m I was good to go.
So make sure you have properly declared your methods on the file that is going to be imported on your viewControllers.
Hope that helps.
In my case I had some very strange path entries in
Framework Search Paths
Library Search Path
(Targets -> YOUR_APP_NAME -> Build Settings in "Search Paths" section)
I removed them and the error messages are gone.
well to begin with I'm sure this is a simple question.
I am developing an iPhone app with the iAd Framework, which only runs for iOS 4.0 or higher.
Still, I wanna choose a iPhone OS 3.0 deployment target, which causes everything to crash.
How do I conditionally include the iAd framework?
...I mean, it would be something like:
...if([[UIDevice currentDevice] systemVersion]>=4.0]) #import
Obviously this won't work because I don't know the correct syntax. Also:
How do I conditionally declare an AdView* variable?
How do I conditionally handle this AdView* variable in my implementation file.
If you guys could help me, I will be very well impressed.
Thanks
You don't need to change your include, you need to make the iAd (or any other new framework) linked weakly:
In your target, find iAd in the linked frameworks and change its "Role" from "Required" to "Weak".
To handle the variable conditionally, use NSClassFromString function, like this:
Class AdClass = NSClassFromString(#"ADBannerView");
if(AdClass) {//if the class exists
ADBannerView* myAd = [[AdClass alloc] initWithFrame:CGRectZero];
// do something with the ad
}
If OS is older than iOS 4.0, AdClass will be nil and the code won't execute. Note that using ADBannerView* as the type of the variable shouldn't cause any problems, as it's just a hint for a compiler and is the same as id after compilation.