我想在 Swift 3.0 中使用 SecRandomCopyBytes
生成随机字节。这是我在 Swift 2.2 中的做法
private static func generateRandomBytes() -> String? {
let data = NSMutableData(length: Int(32))
let result = SecRandomCopyBytes(kSecRandomDefault, 32, UnsafeMutablePointer<UInt8>(data!.mutableBytes))
if result == errSecSuccess {
return data!.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
} else {
print("Problem generating random bytes")
return nil
}
}
在 Swift 3 中,我尝试这样做,因为我知道 unsafemutablebytes 的概念现在不同了,但它不允许我返回。如果我注释掉返回部分,它仍然说 Generic Parameter ResultType could not be inferred
fileprivate static func generateRandomBytes() -> String? {
var keyData = Data(count: 32)
_ = keyData.withUnsafeMutableBytes {mutableBytes in
let result = SecRandomCopyBytes(kSecRandomDefault, keyData.count, mutableBytes)
if result == errSecSuccess {
return keyData.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
} else {
print("Problem generating random bytes")
return nil
}
}
return nil
}
有人知道如何解决这个问题吗?
谢谢
最佳答案
你很接近,但是闭包内的 return
返回
来自闭包,而不是来自外部函数。
因此只有 SecRandomCopyBytes()
应该在
关闭,返回结果。
func generateRandomBytes() -> String? {
var keyData = Data(count: 32)
let result = keyData.withUnsafeMutableBytes {
(mutableBytes: UnsafeMutablePointer<UInt8>) -> Int32 in
SecRandomCopyBytes(kSecRandomDefault, 32, mutableBytes)
}
if result == errSecSuccess {
return keyData.base64EncodedString()
} else {
print("Problem generating random bytes")
return nil
}
}
对于“单表达式闭包”,可以推断出闭包类型 自动,所以这可以缩短为
func generateRandomBytes() -> String? {
var keyData = Data(count: 32)
let result = keyData.withUnsafeMutableBytes {
SecRandomCopyBytes(kSecRandomDefault, 32, $0)
}
if result == errSecSuccess {
return keyData.base64EncodedString()
} else {
print("Problem generating random bytes")
return nil
}
}
Swift 5 更新:
func generateRandomBytes() -> String? {
var keyData = Data(count: 32)
let result = keyData.withUnsafeMutableBytes {
SecRandomCopyBytes(kSecRandomDefault, 32, $0.baseAddress!)
}
if result == errSecSuccess {
return keyData.base64EncodedString()
} else {
print("Problem generating random bytes")
return nil
}
}
关于ios - 在 Swift 中使用 SecRandomCopyBytes,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/39820602/