Question

我正在尝试从Swift中的NSSearchPathForDirectoriesInDomains获取文件路径。它返回NSString，但如果我尝试对其进行任何操作（甚至打印），我会收到Thread 1: EXC_BAD_ACCESS (code=1 address=0x20)错误。

我已经把头撞到了墙上一段时间了，因为这种情况发生在几个地方，我尝试了很多代码。

func webView(webView: UIWebView, shouldStartLoadWithRequest request: NSURLRequest, navigationType: UIWebViewNavigationType) -> Bool {

    NSURLConnection(request: request, delegate: self)
    if (request.URL?.absoluteString!.rangeOfString("attachment=true") != nil) {

        // This line only succeeds with 'as! [NSString]'. If I try 'as! [String]' it fails.
        let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true) as! [NSString]

        // On this line I get the error if I leave the above array as [AnyObject]
        // And try and convert this with 'as! String'. Succeeds with 'as! NSString'.
        let pathString = paths[0]

        // This line always fails with the error. I can't interact with pathString without it failing.
        // Including something as simple as asking for its length.
        let filePath = pathString.stringByAppendingPathComponent("download.pdf")
    }
}

奇怪的是，调试器似乎将paths数组显示为空（但不是nil），但如果超过该行，则pathString被正确设置。

这在iOS 7.1，模拟器和设备中发生。我没有机会在iOS 8中测试它.Xcode 6.3，Swift 1.2

尝试将NSString更改为String或Access NSString时出现线程1：EXC_BAD ACCESS错误

0 个答案: