Question

我有一个Core Foundation字典，我希望找到一个特定的值。当然，我会使用Core Foundation提供的CFDictionaryContainsValue（）。第一个参数是要搜索的Core Foundation字典，第二个参数是var deviceToFind = "disk1" var result: kern_return_t = KERN_FAILURE let classesToMatch = IOServiceMatching(kIOMediaClass) let classesToMatchDict = (classesToMatch as NSDictionary) as! Dictionary<String, AnyObject> let matchedDevices = (classesToMatchDict as NSDictionary) as CFDictionaryRef result = IOServiceGetMatchingServices(kIOMasterPortDefault, classesToMatchCFDictRef, &storageIterator); if CFDictionaryContainsValue(matchedDevices, &deviceToFind) == true { print("Found disk1") }类型。我在字典中寻找一个字符串，所以我尝试了这样的事情：

CFDictionaryContainsValue()

但是在调用var imagePath = "" jQuery(".cheese").each(function (index) { imagePat += jQuery(this).children("img").attr("src") + "\n"; })时只会崩溃（EXC_BAD_ACCESS）。根据{{3}}我正确地构建了调用，但显然存在问题，但我不确定如何使其工作。

Answer 1

要从IOReg获取BSD名称，您无法直接从matchedDevices检索值。您必须遍历storageIterator并分别获取BSD名称属性。

var deviceToFind = "disk1"
var storageIterator = io_iterator_t()
var object : io_object_t
var result: kern_return_t = KERN_FAILURE
let classesToMatchDict = IOServiceMatching("IOMedia")

result = IOServiceGetMatchingServices(kIOMasterPortDefault, classesToMatchDict, &storageIterator)

if KERN_SUCCESS == result && storageIterator != 0 {
  repeat {
    object = IOIteratorNext(storageIterator)
    if let data = IORegistryEntryCreateCFProperty(object, kIOBSDNameKey, kCFAllocatorDefault, 0), disk = data.takeRetainedValue() as? String {
      if deviceToFind == disk {
        print("Found \(deviceToFind)")
        break
      }
    }
  } while object != 0
  IOObjectRelease(storageIterator)
}

Answer 2

将CFDictionary强制转换为Swift字典，然后使用Swift原语可能会减少摩擦。

如果您需要留在CF-land，以下情况应该有效：

let value = "VALUE" as NSString
let dict = ["KEY": "VALUE"] as CFDictionary

if CFDictionaryContainsValue(dict, unsafeAddressOf(value)) {
    print("contains value")
} else {
    print("does not contain value")
}

在Swift中调用CFDictionaryContainsValue（）

2 个答案: