Swift 2 無法使用類型參數列表調用“FSEventStreamCreate”

Question

使用 Swift 2 和 Xcode 7 beta 2 (Build: 7A121l) 我使用 FSEventStream API 和 @convention(c) 得到這個編譯錯誤。

任何建議都會很棒，謝謝！

internal class FileSystem {

init () {

    let allocator: CFAllocator? = kCFAllocatorDefault

    // Create FSEventStream and return valid FSEventStreamRef
    // Alias FSEventStreamCallback - CFunction

    typealias FSEventStreamCallback = @convention(c) (ConstFSEventStreamRef, UnsafeMutablePointer<Void>, UInt, UnsafeMutablePointer<Void>, UnsafePointer<FSEventStreamEventFlags>, UnsafePointer<FSEventStreamEventId>) -> Void

    let callback: FSEventStreamCallback = {
        (streamRef, clientCallBackInfo, numEvents, eventPaths, eventFlags, eventIds) -> Void in
        print ("changed")
        // handle file event
    }

    let context: UnsafeMutablePointer<FSEventStreamContext> = nil
    let pathsToWatch: CFArray = [NSHomeDirectory() + "/Dir"]
    let sinceWhen: FSEventStreamEventId = UInt64(kFSEventStreamEventIdSinceNow)
    let latency: CFTimeInterval = 1.0
    let flags: FSEventStreamCreateFlags = UInt32(kFSEventStreamCreateFlagNone)

    let eventStream = FSEventStreamCreate(
        allocator,
        callback,
        context,
        pathsToWatch,
        sinceWhen,
        latency,
        flags
    )

    FSEventStreamScheduleWithRunLoop(eventStream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode)
    FSEventStreamStart(eventStream)

}
}

Answer 1

您使用了錯誤的簽名（UInt 不是 Int）：

typealias FSEventStreamCallback = @convention(c) (ConstFSEventStreamRef, UnsafeMutablePointer<Void>, Int, UnsafeMutablePointer<Void>, UnsafePointer<FSEventStreamEventFlags>, UnsafePointer<FSEventStreamEventId>) -> Void

這編譯得很好：

init () {

    let allocator: CFAllocator? = kCFAllocatorDefault

    // Create FSEventStream and return valid FSEventStreamRef
    // Alias FSEventStreamCallback - CFunction
    typealias FSEventStreamCallback = @convention(c) (ConstFSEventStreamRef, UnsafeMutablePointer<Void>, Int, UnsafeMutablePointer<Void>, UnsafePointer<FSEventStreamEventFlags>, UnsafePointer<FSEventStreamEventId>) -> Void
    let callback: FSEventStreamCallback = {
        (streamRef, clientCallBackInfo, numEvents, eventPaths, eventFlags, eventIds) -> Void in
        print ("changed")
        // handle file event
    }


    let context: UnsafeMutablePointer<FSEventStreamContext> = nil
    let pathsToWatch: CFArray = [NSHomeDirectory() + "/Dir"]
    let sinceWhen: FSEventStreamEventId = UInt64(kFSEventStreamEventIdSinceNow)
    let latency: CFTimeInterval = 1.0
    let flags: FSEventStreamCreateFlags = UInt32(kFSEventStreamCreateFlagNone)

    let eventStream = FSEventStreamCreate(
        allocator,
        callback,
        context,
        pathsToWatch,
        sinceWhen,
        latency,
        flags
    )

    FSEventStreamScheduleWithRunLoop(eventStream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode)
    FSEventStreamStart(eventStream)

}