swift5 - 'withUnsafeMutableBytes' 已弃用 : use `withUnsafeMutableBytes

Question

我对 Xcode 非常熟悉(提前道歉)。试图使一些旧代码栩栩如生。尝试迁移到 Swift 5 时获得以下信息。

withUnsafeMutableBytes' is deprecated: use withUnsafeMutableBytes<R>(_: (UnsafeMutableRawBufferPointer) throws -> R) rethrows -> R instead

目标:我需要做的就是适本地修改代码并完成。

我查看了其他 Stack Overflow 消息，搜索了各种文章，尝试了不同的东西，但无法快速确定需要更改的内容。我相信对于了解更多的人来说，解决方案非常简单。

var responseData = Data(count: Int(responseDataLength))

        _ = responseData.withUnsafeMutableBytes
        {
            mfError = MFMediaIDResponse_GetAsString(mfMediaIdResponsePtr.pointee, MFString($0), responseDataLength)
        }

Answer 1

这是我的示例，当刷新 withUnsafeMutableBytes 的旧代码时

希望对你有帮助

旧的:

_ = data.withUnsafeMutableBytes { (bytes: UnsafeMutablePointer<UInt8>) in
        memcpy((ioData.pointee.mBuffers.mData?.assumingMemoryBound(to: UInt8.self))!, bytes, dataCount)
    }

新的:

_ = data.withUnsafeMutableBytes { (rawMutableBufferPointer) in
        let bufferPointer = rawMutableBufferPointer.bindMemory(to: UInt8.self)
        if let address = bufferPointer.baseAddress{
            memcpy((ioData.pointee.mBuffers.mData?.assumingMemoryBound(to: UInt8.self))!, address, dataCount)
        }
    }

---

解释:

使用 UnsafeMutablePointer<ContentType> ，你会在它的闭包中得到一个 unsafeMutablePointer。

要访问它的内存，所以需要输入 bindMemory ,

有关 Apple Pointer Doc 的更多详细信息