ios – 如何在Xcode 7 beta 4中调用SecItemCopyMatching？

在使用 Swift的Xcode 6和7的早期版本中,这种语法可以工作：

var secureItemValue: Unmanaged<AnyObject>?

    let statusCode: Osstatus = SecItemcopyMatching(keychainItemQuery,&secureItemValue)
    if statusCode == errSecSuccess
    {
        let opaquePointer = secureItemValue?.toOpaque()

        let secureItemValueData = Unmanaged<NSData>.fromOpaque(opaquePointer!).takeUnretainedValue()

        // Use secureItemValueData...
    }

但是,在Xcode 7 beta 4中,SecItemcopyMatching声明已更改：

OLD：func SecItemcopyMatching(_ query：CFDictionary,_ result：UnsafeMutablePointer< AnyObject？>) – > Osstatus

新：func SecItemcopyMatching(_ query：CFDictionary！,_ result：UnsafeMutablePointer< Unmanaged< AnyObject>？>) – > Osstatus

…现在secureItemValue类型不匹配.

在提取结果之前,这个机制很混乱,我希望新声明在某种程度上更容易,但我不知道如何为secureItemValue变量声明正确的类型并提取结果.

解决方法

这适用于Xcode 7 beta 4

var dataTypeRef: AnyObject?

    let status: Osstatus = withUnsafeMutablePointer(&dataTypeRef) { SecItemcopyMatching(keychainQuery as CFDictionaryRef,UnsafeMutablePointer($0)) }

    if status == noErr {
        return dataTypeRef as? NSData
    }
    else {
        return nil
    }