Cannot call value of non-function type

Question

Having issues trying to convert this to Swift 3.0.

I have:

public typealias CustomCompletionBlock = (_ image: UIImage?, _ error: Error?) -> Void
public var completionBlock : CustomCompletionBlock!

Later on in my code I want to set completionBlock eg:

self.completionBlock(image: nil, error: error)

But I get the error "Cannot call value of non-function type" . What am I doing wrong here?

Answer 1

In CustomCompletionBlock signature,

public typealias CustomCompletionBlock = (_ image: UIImage?, _ error: Error?) -> Void

you have specified _ as the external parameter name for image and error variables. This means while calling CustomCompletionBlock you don't have to specify any parameter names. image and error are internal parameter names ie they must only be used within closure definition.

So you must call it like:

self.completionBlock(nil, error)

Answer 2

尝试这样称呼它：

self.completionBlock(nil, error)