如何在 Swift 语言中调用 Objective C 方法（即返回协议）

Question

I had implemented static library which is written in Objective C language, in new Swift Project. Everything is fine and I can call a class method and instance method in swift code block successfully. But when I try to call a method which is return protocol, I get an error. I have not been calling successfully below method in swift code.

Anyone know how can I call this method in Swift.

Static library which is written with Objective C

I can not call a method which name is getScreenManager. Also, Xcode is not showing hint for this method in Swift.

IScreenManager is below.

 @protocol IScreenManager <NSObject>

@property (weak, nonatomic) id<ScreenManagerDelegate> delegate;
@property (strong, nonatomic) NSDictionary *transitionDictionary;
@property (strong, nonatomic) NSArray *loadingImages;
@property CGFloat loadingAnimationDuration;
@property CGFloat loadingBackgroundAlpha;

- (void)showViewsWithObject:(id)object withMessage:(Response *)message;
- (void)enableScreen;
- (void)disableScreenWillShowLoadingView:(BOOL)willShow;
- (int)getActiveViewId;

- (void)applicationWillEnterForeground;
- (void)applicationDidEnterForeground;
- (void)applicationDidEnterBackground;

Answer 1

if you are using swift 3 or later, then try for a method screenManager as there are lot of naming convention changes in swift 3. And due to this objective-c function calling from swift also affects.

Click here to read more

Answer 2

i found solution. i think, this is a kind of Xcode GM bug. Because i did now how to call this method and i expected Xcode will show hint just like other method.. When i write below code section, Xcode not fired error and build and run successfully. Now i am downloading Xcode 9. Thank all for fast response.

 override func getScreenManager() -> IScreenManager! {
    return MultiLayerScreenManager();
}