Question

在使用Swift的Xcode 6和7的早期版本中，这种语法可行：

    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中更改了SecItemCopyMatching声明：

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，这种机制很混乱，我希望通过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

Answer 1

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
    }

如何在Xcode 7 beta 4中调用SecItemCopyMatching？

1 个答案: