iOS 8 Swift：如何在表格视图的详细信息视图中显示项目的.txt文件？

Question

朋友们！ 我之前曾问过一个问题，在IOS项目中何处放置.txt文件并从中读取文件，并得到了一个很好的工作答案，我现在想将其扩展到我的一个小项目。

我创建了一个简单的TableView Controller，该控制器向我显示了几个名为“ Story1”，“ Story2”等的单元格。

故事本身应该从我的项目“ README1.txt”，“ README2.txt”中的.txt文件中读取。

我无法解决的问题是：“如何在DetailVC显示已分配的.txt文件？也许是因为我的“路径”字符串？

对于故事类型，我创建了一个仅包含名称和文件路径作为字符串的结构。

import Foundation
struct Story {
var name: String
var path: String? //tested as optional or not, no changes
}



 //Code of the Main `Table View Controller`:
 import UIKit

class MainTVC: UITableViewController {

var data = [Story]()

override func viewDidLoad() {
    // append Stories to Table
    let story1 = Story(name: "TestStory1", path: NSBundle.mainBundle().pathForResource("README1", ofType: "txt")!)
    let story2 = Story(name: "TestStory2", path: NSBundle.mainBundle().pathForResource("README2", ofType: "txt")!)

    data.append(story1)
    data.append(story2)

}
//Tells the data source to return the number of rows in a given section of a table view. 
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
    return data.count
}

//Asks the data source for a cell to insert in a particular location of the table view.
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell") as UITableViewCell

    cell.textLabel.text = "\(data[indexPath.row].name)"
    return cell
}
//Asks the delegate for the height to use for a row in a specified location.
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return 75
}

//Notifies the view controller that a segue is about to be performed.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "detail" {
    let row = tableView.indexPathForCell(sender as UITableViewCell)?.row
    (segue.destinationViewController as DetailVC).data = data[row!]
    }
}
}

以及来自Detail View Controller的代码：

import UIKit

class DetailVC: UIViewController {

var data: Story?

@IBOutlet weak var storyTV: UITextView!

override func viewDidLoad() {

    //Show the name of the Story as title
    if let name = data?.name {
        title = name
    }
    else {
        title = "No Story"
    }

    //tried the following lines to get the Story shown
    let pathx = data?.path
    storyTV.text = String(contentsOfFile: data?.path!, encoding: NSUTF8StringEncoding, error: nil) //doesn't work and error occuring because of "data?.path!" just says add "!" to "path" and if i do, it says remove "!". Don't know why?

    storyTV.text = String(contentsOfFile: pathx!, encoding: NSUTF8StringEncoding, error: nil) // doesn't work to show, but don't know why
}
}

Answer 1

这是我通过几个println（）自己发现的问题的答案。 我从类DetailVC中打印出了路径，该路径始终为空，或者开头的字符串为Optinal（“ ...）”。 因此，最终这只是对Optional的误解。

对于具有打开带有变量的文本文件的问题的读者，这里是DetailVC类的最后3行的更正代码：

if let path = data?.path {
        data?.path = path
        storyTV.text = String(contentsOfFile: path, encoding: NSUTF8StringEncoding, error: nil)
    }
    else {
        data?.path = "empty"
    } 

祝你好运。