float *vertexBuffer = (float *)positionSource.data.bytes;
'字节'不可用:改为使用withUnsafeBytes
但我不知道如何使用它
_ = positionSource?.data.withUnsafeBytes({ (<#UnsafePointer<ContentType>#>) -> ResultType in
})
答案 0 :(得分:1)
我认为你可以这样做。
let str = "hello"
let strData = str.data(using: String.Encoding.utf8)!
strData.withUnsafeBytes { (bytes: UnsafePointer<CChar>) -> Void in
print("\(bytes[1])") //exp: access as c string
}
希望能帮到你!
答案 1 :(得分:0)
withUnsafeBytes
是一种通用方法,推断出ContentType
从封闭的类型。与
data.withUnsafeBytes { (vertexBuffer: UnsafePointer<Float>) in
// Use vertexBuffer ...
}
你会得到UnsafePointer<Float>
指向数据中的字节。
请注意,不得在闭包之外使用此指针。
您还可以计算结果并将其从闭包中传回 给来电者。例如:
let result = data.withUnsafeBytes { (vertexBuffer: UnsafePointer<Float>) -> Float in
let result = // ... compute result ...
return result
}