Question

我试图将我的字符串转换为SHA256哈希，但是我收到了下一个错误：

Cannot invoke initializer for type 'UnsafeMutablePointer<UInt8>' with an argument list of type '(UnsafeMutableRawPointer)'

这是我的职责：

func SHA256(data: String) -> Data {
    var hash = NSMutableData(length: Int(CC_SHA256_DIGEST_LENGTH))!

    if let newData: Data = data.data(using: .utf8) {
        let bytes = newData.withUnsafeBytes {(bytes: UnsafePointer<CChar>) -> Void in
            CC_SHA256(bytes, CC_LONG(newData.length), UnsafeMutablePointer<UInt8>(hash.mutableBytes))
        }
    }

    return hash as Data
}

所以，对于这部分

UnsafeMutablePointer<UInt8>(hash.mutableBytes)

我收到此错误：

Cannot invoke initializer for type 'UnsafeMutablePointer<UInt8>' with an argument list of type '(UnsafeMutableRawPointer)'

我该如何解决这个问题以及我做错了什么？

Answer 1

您最好还使用Data作为结果hash。

在Swift 3中，withUnsafePointer(_:)和withUnsafeMutablePointer(:_)是泛型类型，当与“格式良好”的闭包一起使用时，Swift可以正确推断Pointee类型，这意味着您无需手动转换Pointee类型

func withUnsafeBytes((UnsafePointer) -> ResultType)

func withUnsafeMutableBytes((UnsafeMutablePointer) -> ResultType)

func SHA256(data: String) -> Data {
    var hash = Data(count: Int(CC_SHA256_DIGEST_LENGTH))

    if let newData: Data = data.data(using: .utf8) {
        _ = hash.withUnsafeMutableBytes {mutableBytes in
            newData.withUnsafeBytes {bytes in
                CC_SHA256(bytes, CC_LONG(newData.count), mutableBytes)
            }
        }
    }

    return hash
}

在Swift 3中，删除了用于将Pointee类型转换为Swift 2的UnsafePointer和UnsafeMutablePointer的初始值设定项。但在许多情况下，您可以在没有指针类型转换的情况下工作。

无法为类型UnsafeMutablePointer <uint8>

1 个答案: