Question

所以我是swift和iOS编程的新手。我正在尝试记录加速度计和陀螺仪日期并在屏幕上显示。通过一些教程，我设法完成了我的代码并且理解了代码。但我不断收到错误。如果我遵循xcode给我的建议我只会得到更多错误..

所以这是我的代码：

import UIKit
import CoreMotion

class ViewController: UIViewController {

    //instance variables

    var currentMaxAccelX: Double = 0.0
    var currentMaxAccelY: Double = 0.0
    var currentMaxAccelZ: Double = 0.0

    var currentMaxRotX: Double = 0.0
    var currentMaxRotY: Double = 0.0
    var currentMaxRotZ: Double = 0.0

    var motionManager = CMMotionManager()


    //outlets

    @IBOutlet var accX: UILabel?
    @IBOutlet var accY: UILabel?
    @IBOutlet var accZ: UILabel?
    @IBOutlet var maxAccX: UILabel?
    @IBOutlet var maxAccY: UILabel?
    @IBOutlet var maxAccZ: UILabel?
    @IBOutlet var rotX: UILabel?
    @IBOutlet var rotY: UILabel?
    @IBOutlet var rotZ: UILabel?
    @IBOutlet var maxRotX: UILabel?
    @IBOutlet var maxRotY: UILabel?
    @IBOutlet var maxRotZ: UILabel?

    //functions

    @IBAction func resetMaxValues() {
        currentMaxAccelX = 0
        currentMaxAccelY = 0
        currentMaxAccelZ = 0

        currentMaxRotX = 0
        currentMaxRotY = 0
        currentMaxRotZ = 0
    }

    override func viewDidLoad() {

        self.resetMaxValues()

        motionManager.accelerometerUpdateInterval = 0.2
        motionManager.gyroUpdateInterval = 0.2

        //start recording data

        motionManager.startAccelerometerUpdatesToQueue(NSOperationQueue.currentQueue(), withHandler: {(accelerometerData: CMAccelerometerData!, error: NSError!) -> Void in
            self.outputAccelerometerData(accelerometerData.acceleration)
            if (error != nil) {
                print("\(error)")
            }
        })

        motionManager.startGyroUpdatesToQueue((NSOperationQueue.currentQueue()), withHandler: {(gyroData: CMGyroData!, error: NSError!) -> Void in
            self.outputRotationData(gyroData.rotationRate)
            if (error! = nil) {
                print("\(error)")
            }
        })

        super.viewDidLoad()

    }

    func outputAccelerometerData(acceleration: CMAcceleration) {

        accX?.text = "\(acceleration.x).2fg"

        if fabs(acceleration.x) > fabs(currentMaxAccelX) {
            currentMaxAccelX = acceleration.x
        }

        accY?.text = "\(acceleration.y).2fg"

        if fabs(acceleration.y) > fabs(currentMaxAccelY) {
            currentMaxAccelY = acceleration.y
        }

        accZ?.text = "\(acceleration.z).2fg"

        if fabs(acceleration.z) > fabs(currentMaxAccelZ) {
            currentMaxAccelZ = acceleration.z
        }

        maxAccX?.text = "\(currentMaxAccelX) .2f"
        maxAccY?.text = "\(currentMaxAccelY) .2f"
        maxAccZ?.text = "\(currentMaxAccelZ) .2f"

    }

    func outputRotationData(rotation: CMRotationRate) {

        rotX?.text = "\(rotation.x).2fr/s"

        if fabs(rotation.x) > fabs(currentMaxRotX) {
            currentMaxRotX = rotation.x
        }

        rotY?.text = "\(rotation.y).2fr/s"

        if fabs(rotation.y) > fabs(currentMaxRotY) {
            currentMaxRotY = rotation.y
        }

        rotZ?.text = "\(rotation.z).2fr/s"

        if fabs(rotation.z) > fabs(currentMaxRotZ) {
            currentMaxRotZ = rotation.z
        }



    }



    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



}

这是我一直想要开始记录数据的错误;可选类型'NSOperationQueue？'的值没有打开;你的意思是用“！”或“？”？

对不起，如果这是一个愚蠢的问题，但我真的想了解这些东西！

提前致谢!!

Answer 1

由于24 %let _path = C:\; 25 %let _name = AOL.xlsx; 26 %let sheet_list = AG ST; 27 28 %macro Import(dlm=%str( )); 29 %local current_sheet i; 30 %let i = 1; 31 %let current_sheet = %scan(%superq(sheet_list),&i,&dlm); 32 %do %while(%superq(current_sheet) ne); 33 %put proc import out=SQ_&current_sheet. replace datafile="&_path.\&_name."; 34 %put sheet="&current_sheet."; 35 %put run; 36 %let i = %eval(&i + 1); 37 %let current_sheet = %scan(%superq(sheet_list),&i,&dlm); 38 %end; 39 %mend Import; 40 41 %Import; proc import out=SQ_AG replace datafile="C:\\AOL.xlsx" sheet="AG" run proc import out=SQ_ST replace datafile="C:\\AOL.xlsx" sheet="ST" run 42 43 %let sheet_list = AG 11, AG 12, ST; 44 %import(dlm=%str(,)); proc import out=SQ_AG 11 replace datafile="C:\\AOL.xlsx" sheet="AG 11" run proc import out=SQ_AG 12 replace datafile="C:\\AOL.xlsx" sheet="AG 12" run proc import out=SQ_ST replace datafile="C:\\AOL.xlsx" sheet="ST" run是可选的，您需要使用NSOperationQueue强制解包它。

因此，请将!替换为NSOperationQueue.currentQueue()。

您可以通过此Apple Documentation和此blog来了解Swift选项。

Answer 2

问题是

NSOperationQueue.currentQueue()

返回一个可选值（参考NSOperationQueue Class Reference）。但是，

startAccelerometerUpdatesToQueue:withHandler:
startGyroUpdatesToQueue: withHandler:

需要一个展开的NSOperationQueue对象（请参阅：CMMotionManager Class Reference），但在您的代码中，您传递的是可选值，这就是您收到这些错误的原因。

要进行修复，请将这些方法调用更改为：

motionManager.startAccelerometerUpdatesToQueue(NSOperationQueue.currentQueue()!, withHandler: {(accelerometerData: CMAccelerometerData!, error: NSError!) -> Void in
{
})

motionManager.startGyroUpdatesToQueue((NSOperationQueue.currentQueue()!), withHandler: {(gyroData: CMGyroData!, error: NSError!) -> Void in
{
})

Swift可选类型问题

2 个答案: