Swift：使用与Objective-C块兼容的闭包

Question

I tried to define a closure using the following Objective-C blocks:

typedef void(^UPBaseEventAPIArrayCompletion)(NSArray *results, UPURLResponse *response, NSError *error);

+ (void)getFriendsWithCompletion:(UPBaseEventAPIArrayCompletion)completion;

in this:

UPUserAPI.getFriendsWithCompletion({(friends: [AnyObject], response: UPURLResponse, error: NSErrorPointer) -> Void in

    })

... and got the following error (see image):

Cannot convert value of type '([AnyObject], UPURLResponse, NSErrorPointer) -> Void' to expected argument type 'UPBaseEventAPIArrayCompletion!'

What's the correct way to do this?

Answer 1

Try this.

UPUserAPI.getFriendsWithCompletion({(friends: [AnyObject]?, response: UPURLResponse?, error: NSError?) -> Void in
    //code 
})

In the Objective C code, any of those parameters could be nil. So in Swift, these parameters have to be defined as Optionals.