Swift 2.0代码适用于Xcode,但不适用于Playground_app

概述我正在学习 Swift并且一直在试图弄清楚我无法加载文件.事实证明,代码在Xcode中工作,但在 *** 场上不起作用.这是什么原因？这是代码： func testFileLoad(){ let myFilePath: String = "/Users/clay/Desktop/test.txt" let t: Bool = NSFileManager.defaultManager(). 我正在学习 Swift并且一直在试图弄清楚我无法加载文件.事实证明,代码在Xcode中工作,但在 *** 场上不起作用.这是什么原因？

这是代码：

func testfileLoad(){    let myfilePath: String = "/Users/clay/Desktop/test.txt"    let t: Bool = NSfileManager.defaultManager().fileExistsAtPath(myfilePath)    print(t)    let s: String = try! String(contentsOffile: myfilePath,enCoding: NSUTF8StringEnCoding)    print(s)    do {        let p: String = try String(contentsOffile: myfilePath,enCoding: NSUTF8StringEnCoding)        print(p)    } catch {        print("nope")    }}

在Xcode的测试模块中运行,它可以正常工作并打印我希望的控制台.

Test Suite 'Selected tests' started at 2015-08-05 14:24:15.977 Test Suite 'swiftgraphTests' started at 2015-08-05 14:24:15.978 Test Case '-[swiftgraphTests.swiftgraphTests testfileLoad]' started. true this is a test this is a test Test Case '-[swiftgraphTests.swiftgraphTests testfileLoad]' passed (0.001 seconds). Test Suite 'swiftgraphTests' passed at 2015-08-05 14:24:15.979.          Executed 1 test,with 0 failures (0 unexpected) in 0.001 (0.001) seconds Test Suite 'Selected tests' passed at 2015-08-05 14:24:15.979.       Executed 1 test,with 0 failures (0 unexpected) in 0.001 (0.002) seconds

在 *** 场上,我明白了：

我在这做错了什么？我不正确地使用 *** 场吗？

如果你去菜单

“VIEw” -> “DeBUG Area” -> “Show DeBUG Area”

您将看到完整错误：“您无权从Playground *访问文件系统.”

解决方法是使用Project Navigator将文件包含在Playground中.

转到菜单

“VIEw” -> “Navigators” -> “Show Project Navigator”

然后将文件拖放到“Resources”文件夹中.

然后使用NSBundle获取路径.

func testfileLoad() {    // get the file path for the file from the Playground's Resources folder    guard let path = NSBundle.mainBundle().pathForResource("test",ofType: "txt") else {            print("Oops,the file is not in the Playground")            return    }    // keePing the examples from your question    let s: String = try! String(contentsOffile: path,enCoding: NSUTF8StringEnCoding)    print(s)    do {        let p: String = try String(contentsOffile: path,enCoding: NSUTF8StringEnCoding)        print(p)    } catch {        print("nope")    }}testfileLoad()

*实际上,您只能访问包含Playground共享数据的/ var /文件夹,而Playground只提供快捷方式. Playground导航器中的此文件夹实际上代表/ var /文件夹,并且对于每个Playground都是唯一的.您可以使用NSBundle查看其地址：