在以前的测试版中,我能够将指向任何东西的指针传递给C做类似的事情
var aString : NSString = "This is a string" // create an NSString var anUnmanaged = Unmanaged.passUnretained(aString) // take an unmanaged pointer var opaque : COpaquePointer = anUnmanaged.toOpaque() // convert it to a COpaquePointer var mut : CMutablePointer = &opaque // this is a CMutablePointer doSomething(mut) // pass the pointer to an helper function written in C
使用C函数如下:
void doSomething(void ** ptr) { // do something with the pointer,change it and make it point to another nsstring for example }
现在,(肯定在Beta4中,甚至可能在Beta3中)从C转换为Swift的语法已经改变
之前,doSomething函数期待CMutablePointer(现在已从Swift中删除)
现在,它期望:
UnsafePointer<UnsafePointer<()>>
()是Void的类型
所以,语法上的说话更清楚.
但是,现在我无法理解如何获取任何对象的void **指针,就像我在之前的测试版中所做的那样.
有什么建议吗?
这对我有用:
var str = "Hello,playground" var p: UnsafePointer<Void> = unsafeAddressOf(str)