使用Swift 3.0设置CFDictionary中的值

Question

我刚开始使用swift 3.0。我尝试定义一个CFDictionary来设置value.When代码运行到"CFDictionarySetValue“的函数，我得到这个错误: EXC_BAD_ACCESS(code=1，address=0x7e8)

    var keyCallBacks = kCFTypeDictionaryKeyCallBacks
    var valueCallBacks = kCFTypeDictionaryValueCallBacks
    let query = CFDictionaryCreateMutable(kCFAllocatorDefault, 4, &keyCallBacks,&valueCallBacks)

    var secClass = kSecClass
    var genericPassword = kSecClassGenericPassword
    CFDictionarySetValue(query,&secClass, &genericPassword)


    var attrCount = kSecAttrAccount
    var accountStr = "nothing_account" as CFString
    CFDictionarySetValue(query, &attrCount, &accountStr)

Answer 1

不需要使用繁琐的语法来创建CF..集合类型，您可以将字典声明为Swift Dictionary -您必须对其进行显式注释，并将键桥接到String -并将字典桥接到CFDictionary，例如：

let query : [String: Any] = [kSecClass as String : kSecClassGenericPassword, 
                             kSecAttrAccount as String : "nothing_account"]

var result : CFTypeRef?
let status = SecItemCopyMatching(query as CFDictionary, &result)