难以打开文本文件

Question

我正在尝试合并一个文件浏览器，该浏览器允许用户选择一个文本文件，并将文件的内容显示在 NSTextView 中。我的文件浏览器工作正常，文本框工作，但我似乎无法打开文件并从中生成至少一个或最好是一系列字符串（每行 1 个）。

let FileWindow : NSOpenPanel = NSOpenPanel()
    FileWindow.prompt = "Open File"
    FileWindow.title = "Select a File"
    FileWindow.allowedFileTypes = ["txt"]
    FileWindow.canChooseDirectories = false
    FileWindow.allowsMultipleSelection = false
    FileWindow.runModal()
    var selectedfile = FileWindow.URL
    var output = selectedfile?.absoluteString
    var index: String.Index = advance(output!.startIndex, 7)
    FileLabel.stringValue = output!.substringFromIndex(index)

if (selectedfile != nil) {
var data: NSData = NSFileManager.defaultManager().contentsAtPath(output!.substringFromIndex(index))!
        var txt: NSString = NSString(data: data, encoding: NSUTF8StringEncoding)!
        self.FileDisplayView.textStorage?.mutableString.appendString(txt)
        self.FileDisplayView.needsDisplay = true
    }  

任何帮助将不胜感激！

Answer 1

更新：Xcode 7.1 • Swift 2.1

你应该使用 String(contentsOfFile:) 或 String(contentsOfURL:)

创建这个类来处理打开的文本文件：

public class File {

    class func open(path: String, encoding: NSStringEncoding = NSUTF8StringEncoding) -> String? {
        guard  NSFileManager().fileExistsAtPath(path) else { return nil }
        do {
            return try String(contentsOfFile: path, encoding: encoding)
        } catch let error as NSError {
            print(error.localizedDescription)
            return nil
        }
    }
    class func save(path: String, fileContent: String, encoding: NSStringEncoding = NSUTF8StringEncoding) -> Bool {
        do {
            try fileContent.writeToFile(path, atomically: true, encoding: encoding)
            return true
        } catch let error as NSError {
            print(error.localizedDescription)
            return false
        }
    }
}

class Url {
    class func read(urL: NSURL, encoding: NSStringEncoding = NSUTF8StringEncoding) -> String? {
        do {
            return try String(contentsOfURL: urL, encoding: encoding)
        } catch let error as NSError {
            print(error.localizedDescription)
            return nil
        }
    }
    class func write(urL: NSURL, fileContent: String, encoding: NSStringEncoding = NSUTF8StringEncoding) -> Bool {
        do {
            try fileContent.writeToURL(urL, atomically: true, encoding: encoding)
            return true
        } catch let error as NSError {
            print(error.localizedDescription)
            return false
        }
    }

}

用法如下：

if let loadedString = File.open("\(NSHomeDirectory())/Desktop/file.txt") {
    println(loadedString)
} else {
    println("error reading file")
}  

或打开您的网址：

if let loadedString = Url.read(yourUrl) {
    println(loadedString)
} else {
    println("error reading file")
}