ios - 无法将类型 'NSObject?' 的值分配给类型 'UIColor?' 的值

Question

我试图将单元格的背景颜色设置为等于字典中的 UI 颜色，但我不断收到以下错误。即使将其作为数组传递时它也能工作吗？

import UIKit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet weak var tableView: UITableView!

    let colourList = [["Color" : "Red", "colourCode" : UIColor.redColor()],
                        ["Color" : "Yellow", "colourCode" :     UIColor.yellowColor()],
                        ["Color" : "Purple", "colourCode" : UIColor.purpleColor()],
                        ["Color" : "Green", "colourCode" : UIColor.greenColor()],
                        ["Color" : "Blue", "colourCode" : UIColor.blueColor()],
                        ["Color" : "Orange", "colourCode" : UIColor.orangeColor()]]

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.tableView.dataSource = self
        self.tableView.delegate = self
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = UITableViewCell()
        let dict = colourList[indexPath.row]
        print(dict) // e.g ["Colour": "Red", "colourCode": UIDeviceRGBColorSpace 1 0 0 1] 
        print(dict["colourCode"]!) // e.g UIDeviceRGBColorSpace 1 0 0 1
        cell.backgroundColor = dict["colourCode"] \\ ERROR - Cannot assign a value of type 'NSObject?' to a value of type 'UIColor?'

        return cell
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.colourList.count
    }
}

Answer 1

用作!明确告诉它的类型

cell.backgroundColor = dict["colourCode"] as! UIColor