Question

我正通过BLE从传感器检索数据。我正在将字节从NSData转换为带符号的16位整数数组。但是我收到错误说

Argument type '[Int16]' does not conform to expected type '_Pointer'

有更好的方法吗？任何帮助表示赞赏。

func peripheral(peripheral: CBPeripheral!, didUpdateValueForCharacteristic characteristic: CBCharacteristic!, error: NSError!) {

    if characteristic.uuid == tempUUID {

        let dataBytes = characteristic.value
        let dataCount = dataBytes?.count

        var dataArray = [Int16](repeating: 0, count: dataCount!)
        dataBytes.getBytes(dataArray, length:dataCount! * MemoryLayout<Int16>.size)

        let finalAnswer = Double(dataArray[1])/128

Answer 1

这是你可以将数据复制到整数数组中的方法（Swift 3/4）：

if let data = characteristic.value {
    let i16value = data.withUnsafeBytes { (ptr: UnsafePointer<Int16>) in
        ptr[1]
    }
    let finalAnswer = Double(i16value)/128
}

如果您只需要一个值，那么您可以在不使用的情况下访问它创建一个数组：

if let data = characteristic.value {
    let i16value = data.subdata(in: 2..<4).withUnsafeBytes {
        UnsafeRawPointer($0).load(as: Int16.self)
    }
    let finalAnswer = Double(i16value)/128
}

另一种选择：

UITextField

无法转换为带符号的16位数组

1 个答案: