相关疑难解决方法(0)

在调用以下代码时,尝试将"self"传递给swift中的C函数:

var callbackStruct : AURenderCallbackStruct = 
    AURenderCallbackStruct.init(
      inputProc: recordingCallback,
      inputProcRefCon: UnsafeMutablePointer<Void>
    )

在这里将"self"转换为UnsafeMutablePointer类型的理想方法是什么？

在"ViewController.swift"中我创建了这个回调:

func callback(cf:CFNotificationCenter!, 
    ump:UnsafeMutablePointer<Void>, 
    cfs:CFString!, 
    up:UnsafePointer<Void>, 
    cfd:CFDictionary!) -> Void {

}

使用此观察者:

CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), 
    nil, 
    self.callback, 
    "myMESSage", 
    nil, 
    CFNotificationSuspensionBehavior.DeliverImmediately)

导致此编译器错误:

"AC函数指针只能通过对'func'或文字闭包的引用形成"

我想检测我的应用程序中插入/删除的特定USB.现在,我可以通过本教程使用USB设备接口获取deviceName .但是,如何在Swift 中执行(deviceAdded)IOServiceMatchingCallBack的回调函数.

我尝试如下,但我收到一个错误:无法将类型'(UnsafePointer,iterator:io_iterator_t) - >()'的值转换为预期的参数类型'IOServiceMatchingCallback!'

func detectUSBEvent() {
    var portIterator: io_iterator_t = 0
    var kr: kern_return_t = KERN_FAILURE
    let matchingDict = IOServiceMatching(kIOUSBDeviceClassName)

    let vendorIDString = kUSBVendorID as CFStringRef!
    let productIDString = kUSBProductID as CFStringRef!
    CFDictionarySetValue(matchingDict, unsafeAddressOf(vendorIDString), unsafeAddressOf(VendorID))
    CFDictionarySetValue(matchingDict, unsafeAddressOf(productIDString), unsafeAddressOf(ProductID))

    // To set up asynchronous notifications, create a notification port and add its run loop event source to the program’s run loop
    let gNotifyPort: IONotificationPortRef = IONotificationPortCreate(kIOMasterPortDefault)
    let runLoopSource: Unmanaged<CFRunLoopSource>! = IONotificationPortGetRunLoopSource(gNotifyPort)
    let gRunLoop: …