ios - Swift 将数据转换为 UnsafeMutablePointer

Question

我正在从 swift 调用 objective-c 类中的函数。

-(char *)decrypt:(char *)crypt el:(int)el{}

当从 swift 调用这个函数时，它要求一个 UnsafeMutablePointer<Int8>作为参数 'crypt'

的值

'crypt' 的值来自服务器，它是一个 base64 编码的字符串。所以我对该字符串进行解码并得到一个数据对象。

let resultData = Data(base64Encoded: base64String)

现在我需要将这些数据传递给上面提到的函数。我试图将此数据对象转换为 UnsafeMutablePointer<Int8>

resultData?.withUnsafeBytes { (u8Ptr: UnsafeMutablePointer<Int8>) in
                    let decBytes = tea?.decrypt(u8Ptr , el: el)}

但它没有编译。给出以下错误

'UnsafeMutablePointer' is not convertible to 'UnsafePointer<_>'

我对 objective-c 知之甚少。那么谁能帮我把这个参数传递给 objective-c 函数。

Answer 1

你必须将 UnsafeMutablePointer 更改为 UnsafePointer

不安全指针

resultData?.withUnsafeBytes {(bytes: UnsafePointer<CChar>)->Void in
            //Use `bytes` inside this closure

        }

UnsafeMutablePointer

 var data2 = Data(capacity: 1024)
data2.withUnsafeMutableBytes({ (bytes: UnsafeMutablePointer<UInt8>) -> Void in
                 //Use `bytes` inside this closure

            })