Question

我试过这个

 return areKeysConsistent(
     certificate as! UnsafeMutablePointer<UInt8>,
     certificate.lengthOfBytes(using: <#T##String.Encoding#>.utf8),
     privateKey as! UnsafeMutablePointer<UInt8>,
     privateKey.lengthOfBytes(using: <#T##String.Encoding#>.utf8),
     password as! UnsafeMutablePointer<UInt8>
 )

但是IDE说 - “字符串始终失败。

转换它的正确方法是什么？，谢谢

Answer 1

这是您必须使用C语言时遇到的一些复杂问题。

这里主要关注的是传递给该函数的指针的生命周期。我下面的代码使用指向Swift字符串缓冲区的指针。如果areKeysConsistent捕获这些指针供以后使用，这将是一个问题。 ARC可能会释放Swift字符串，使这些存储的指针成为悬空指针。

func areKeysConsistent(
        _ cert: UnsafeMutablePointer<UInt8>, _ certLength: Int,
        _ key: UnsafeMutablePointer<UInt8>, _ keyLength: Int,
        _ pass: UnsafeMutablePointer<UInt8>, _ passLength: Int
    ) {
    print(cert, key, pass)
}

let certificate = "cert"
let privateKey = "key"
let password = "password"

var certificateCString = certificate.utf8CString
var privateKeyCString = privateKey.utf8CString
var passwordCString = password.utf8CString


certificateCString.withUnsafeMutableBytes { certUMRBP in
privateKeyCString.withUnsafeMutableBytes { pkUMRBP in
passwordCString.withUnsafeMutableBytes { passUMRBP in

    areKeysConsistent(
        certUMRBP.baseAddress!.bindMemory(to: UInt8.self, capacity: certUMRBP.count),
        certUMRBP.count,
        pkUMRBP.baseAddress!.bindMemory(to: UInt8.self, capacity: pkUMRBP.count),
        pkUMRBP.count,
        passUMRBP.baseAddress!.bindMemory(to: UInt8.self, capacity: passUMRBP.count),
        passUMRBP.count
    )
}
}
}

Answer 2

感谢@Alexander解决了我的问题，这是我的代码：

var string = 'word word words things amazing icons yup'

console.log(string)

string = string.replace(/(\S)(\S*)/g, function (_, first, rest) {
  return first.toUpperCase() + rest
})

console.log(string)

Answer 3

尝试一下（快速4）：

func stringToUnsafeMutablePointer(message: String) -> UnsafeMutablePointer<Int8> {
    var messageCString = message.utf8CString
    return messageCString.withUnsafeMutableBytes { mesUMRBP in
        return mesUMRBP.baseAddress!.bindMemory(to: Int8.self, capacity: mesUMRBP.count)
    }

}

如何将String转换为UnsafeMutablePointer <uint8>？斯威夫特3

3 个答案: