如何将简单的保存加载函数添加到基于文档的Swift 3应用程序？

Question

我正在学习Swift（只是一个爱好），并试图找出我应该如何保存和加载函数到基于文档的swift应用程序中的document.swift文件？我想知道如何保存和加载简单的txt文件。我正在使用NSTextView，所以我想我必须将其更改为NSString？

以下是这些功能的时刻：

override func data(ofType typeName: String) throws -> Data { 
     // Insert code here to write your document to data of the specified type. If outError != nil, ensure that you create and set an appropriate error when returning nil. 
     // You can also choose to override fileWrapperOfType:error:, writeToURL:ofType:error:, or writeToURL:ofType:forSaveOperation:originalContentsURL:error: instead. 
     throw NSError(domain: NSOSStatusErrorDomain, code: unimpErr, userInfo: nil)  
    } 

override func read(from data: Data, ofType typeName: String) throws { 
     // Insert code here to read your document from the given data of the specified type. If outError != nil, ensure that you create and set an appropriate error when returning false. 
     // You can also choose to override readFromFileWrapper:ofType:error: or readFromURL:ofType:error: instead. 
     // If you override either of these, you should also override -isEntireFileLoaded to return false if the contents are lazily loaded. 
     throw NSError(domain: NSOSStatusErrorDomain, code: unimpErr, userInfo: nil) 

    } 

Answer 1

在你document.swift以下文件这些功能将加载并设置文本视图的字符串值。

希望这会有所帮助！

var content = "" 
override func makeWindowControllers() { 
    //Make the window controller 
    let storyboard = NSStoryboard(name: "Main", bundle: nil) 
    let windowController = storyboard.instantiateController(withIdentifier: "Document Window Controller") as! NSWindowController 
    self.addWindowController(windowController) 

    //Access the view controller 
    let vc = windowController.contentViewController as! ViewController 
    //Set the text view string to the variable that was loaded 
    vc.textView.string = content 
} 

override func data(ofType typeName: String) throws -> Data { 
    //Access the current view controller 
    if let vc = self.windowControllers[0].contentViewController as? ViewController { 
     //Get the textView's String Value; or call a function that will create a string of what needs to be saved 
     return vc.textView.string?.data(using: String.Encoding.utf8) ?? Data() 
    }else { 
     throw NSError(domain: NSOSStatusErrorDomain, code: unimpErr, userInfo: nil) 
    } 
} 

override func read(from url: URL, ofType typeName: String) throws { 
    do { 
     //Set a string variable to the loaded string 
     //We can't directly set the text views string value because this function is called before the makeWindowControllers() so now text view is created yet. 
     content = try String(contentsOf: url, encoding: String.Encoding.utf8) 
    }catch { 
     throw NSError(domain: NSOSStatusErrorDomain, code: unimpErr, userInfo: nil) 
    } 
}