Question

这是我在appDelegate中的代码didFinishLaunchingWithOptions（）

  var paths : NSArray =  NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
    var documentsDirectory = paths.objectAtIndex(0)
    var fileName: String = String(format: "Logger.txt")
    var logFilePath : NSString = documentsDirectory.stringByAppendingPathComponent(fileName)
    freopen(logFilePath, "a+", stderr)

我得到的错误是无法将NSString转换为UnSafepointer。任何人都可以帮助我如何实现这个？

Answer 1

只需从NSString

中删除logFilePath即可

var paths : NSArray =  NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
var documentsDirectory = paths.objectAtIndex(0)
var fileName: String = String(format: "Logger.txt")
var logFilePath = documentsDirectory.stringByAppendingPathComponent(fileName)
freopen(logFilePath, "a+", stderr)

更安全的方法就是这样：

let file = "Logger.txt"
let text = "A safer way to do this"

if let directory : NSString = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true).first {
    let path = directory.stringByAppendingPathComponent(file);

    print(path)

    do {
        try text.writeToFile(path, atomically: false, encoding: NSUTF8StringEncoding)
    }
    catch {
    }
}

Answer 2

放开铸造; - ）

所有你需要施放的是NSArray来获取objectAtIndex（）方法

let paths : NSArray =  NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let documentsDirectory = paths.objectAtIndex(0)
let fileName = String(format: "Logger.txt")
let logFilePath = documentsDirectory.stringByAppendingPathComponent(fileName)
freopen(logFilePath, "a+", stderr)

额外奖励：使用let代替var。

编辑：

没有NSArray＆amp;的NSString：

let paths =  NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let documentsDirectory = paths[0]
let fileName = String(format: "Logger.txt")
let logFilePath = NSURL(fileURLWithPath: documentsDirectory).URLByAppendingPathComponent(fileName).absoluteString
freopen(logFilePath, "a+", stderr)

在swift中写一个文件

2 个答案: