Swift 3 - 无法将类型 'String?' 的值分配给类型 'NSDate' MasterViewController.swift

Question

它发生在关于 iOS split view 的示例源代码中。

我想将 URL 信息发送到 detailViewController，因此首先定义名为 siteAddresses 类型的变量 String。

var siteAddresses : [String]?

然后在 siteAddresses 数组中输入值:

siteAddresses = ["www.google.com", "www.apple.com"]

并定义函数 prepare for segue like

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "showDetail" {
        if let indexPath = self.tableView.indexPathForSelectedRow {
            let urlString = siteAddresses?[indexPath.row]
            let controller = (segue.destination as! UINavigationController).topViewController as! DetailViewController
            controller.detailItem = urlString
            controller.navigationItem.leftBarButtonItem = self.splitViewController?.displayModeButtonItem
            controller.navigationItem.leftItemsSupplementBackButton = true
        }
    }
}

但是

controller.detailItem = urlString

这部分在运行时会出现问题。

错误是:

"Cannot assign value of type 'String?' to type 'NSDate?'"

//编辑

DetailViewController(接口(interface)):

internal var detailItem: NSDate? { get set }

声明:

 func configureView() {
        // Update the user interface for the detail item.
        if let detail = detailItem {

            if let myWebview = self.webView{
                let url = NSURL(string: detailItem as String)
                let request = NSURLRequest(URL : url!)
                myWebview.scalesPageToFit = true
                myWebview.loadRequest(request)
            }
        }
    }

Answer 1

1. 准备函数

   controller.detailItem = urlString

   到

   controller.detailItem = urlString as AnyObject？

2. 添加DetailViewController

    var detailItem: AnyObject? {
       didSet {
           self.configureView()
       }
   }