我在玩苹果的新Swift编程语言,遇到了一些问题…
目前我试图读取一个plist文件,在Objective-C中,我会做以下工作来获取内容作为NSDictionary:
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"Config" ofType:@"plist"];
NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:filePath];
我如何得到一个plist作为一个字典在Swift?
我假设我可以得到路径到plist:
let path = NSBundle.mainBundle().pathForResource("Config", ofType: "plist")
当这工作(如果它是正确的?):我如何获得内容作为一个字典?
还有一个更普遍的问题:
是否可以使用默认的NS*类?我想是的……还是我遗漏了什么?据我所知,默认框架NS*类仍然有效,可以使用吗?
你可以使用它,我在github https://github.com/DaRkD0G/LoadExtension中创建了一个简单的字典扩展
extension Dictionary {
/**
Load a Plist file from the app bundle into a new dictionary
:param: File name
:return: Dictionary<String, AnyObject>?
*/
static func loadPlistFromProject(filename: String) -> Dictionary<String, AnyObject>? {
if let path = NSBundle.mainBundle().pathForResource("GameParam", ofType: "plist") {
return NSDictionary(contentsOfFile: path) as? Dictionary<String, AnyObject>
}
println("Could not find file: \(filename)")
return nil
}
}
你可以用它来计算负载
/**
Example function for load Files Plist
:param: Name File Plist
*/
func loadPlist(filename: String) -> ExampleClass? {
if let dictionary = Dictionary<String, AnyObject>.loadPlistFromProject(filename) {
let stringValue = (dictionary["name"] as NSString)
let intergerValue = (dictionary["score"] as NSString).integerValue
let doubleValue = (dictionary["transition"] as NSString).doubleValue
return ExampleClass(stringValue: stringValue, intergerValue: intergerValue, doubleValue: doubleValue)
}
return nil
}
步骤1:简单和最快的方法来解析plist在swift 3+
extension Bundle {
func parsePlist(ofName name: String) -> [String: AnyObject]? {
// check if plist data available
guard let plistURL = Bundle.main.url(forResource: name, withExtension: "plist"),
let data = try? Data(contentsOf: plistURL)
else {
return nil
}
// parse plist into [String: Anyobject]
guard let plistDictionary = try? PropertyListSerialization.propertyList(from: data, options: [], format: nil) as? [String: AnyObject] else {
return nil
}
return plistDictionary
}
}
第二步:使用方法:
Bundle().parsePlist(ofName: "Your-Plist-Name")
以下是我找到的解决方案:
let levelBlocks = NSDictionary(contentsOfFile: NSBundle.mainBundle().pathForResource("LevelBlocks", ofType: "plist"))
let test: AnyObject = levelBlocks.objectForKey("Level1")
println(test) // Prints the value of test
我将测试类型设置为AnyObject,以关闭关于可能发生的意外推断的警告。
而且,它必须在类方法中完成。
访问并保存已知类型的特定值:
let value = levelBlocks.objectForKey("Level1").objectForKey("amount") as Int
println(toString(value)) // Converts value to String and prints it
你仍然可以在Swift中使用nsdictionary:
Swift 4
var nsDictionary: NSDictionary?
if let path = Bundle.main.path(forResource: "Config", ofType: "plist") {
nsDictionary = NSDictionary(contentsOfFile: path)
}
Swift 3+
if let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
let myDict = NSDictionary(contentsOfFile: path){
// Use your myDict here
}
以及旧版本的Swift
var myDict: NSDictionary?
if let path = NSBundle.mainBundle().pathForResource("Config", ofType: "plist") {
myDict = NSDictionary(contentsOfFile: path)
}
if let dict = myDict {
// Use your dict here
}
NSClasses仍然可用,完全可以在Swift中使用。我想他们可能很快就会把重点转移到swift上,但是目前swift api并没有核心NSClasses的所有功能。
通过尼克的回答转换成一个方便的扩展:
extension Dictionary {
static func contentsOf(path: URL) -> Dictionary<String, AnyObject> {
let data = try! Data(contentsOf: path)
let plist = try! PropertyListSerialization.propertyList(from: data, options: .mutableContainers, format: nil)
return plist as! [String: AnyObject]
}
}
用法:
let path = Bundle.main.path(forResource: "plistName", ofType: "plist")!
let url = URL(fileURLWithPath: path)
let dict = Dictionary<String, AnyObject>.contentsOf(path: url)
我敢打赌,它也可以为数组创建类似的扩展
我使用swift字典,但在我的文件管理器类中转换它们和nsdictionary,如下所示:
func writePlist(fileName:String, myDict:Dictionary<String, AnyObject>){
let docsDir:String = dirPaths[0] as String
let docPath = docsDir + "/" + fileName
let thisDict = myDict as NSDictionary
if(thisDict.writeToFile(docPath, atomically: true)){
NSLog("success")
} else {
NSLog("failure")
}
}
func getPlist(fileName:String)->Dictionary<String, AnyObject>{
let docsDir:String = dirPaths[0] as String
let docPath = docsDir + "/" + fileName
let thisDict = NSDictionary(contentsOfFile: docPath)
return thisDict! as! Dictionary<String, AnyObject>
}
这似乎是最不麻烦的读写方式,但让我的其余代码保持尽可能快。