Question

我正在创建一个需要创建目录才能下载某些文件的应用。当我打电话

[[NSFileManager defaultManager] createDirectoryAtPath:
[[self.searchURL theDownloadLocation] stringByStandardizingPath]
withIntermediateDirectories:YES attributes:nil error:nil];

内

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification

它工作正常。我有一个按钮，应该开始下载。我已将它放在xib文件中，它可以做任何其他事情，所以我知道按钮有效。同样，如果我在NSFileManager内调用applicationDidFinishLaunching方法，但在按下按钮时调用的其他方法内，则创建目录没有问题。它与(lldb)消息崩溃。

传递的参数完全相同，我甚至NSLog在按钮方法中[[self.searchURL theDownloadLocation] stringByStandardizingPath]，它肯定是NSString，所以按下按钮时会记录。我错过了什么？

我有时收到错误消息：

2013-02-12 19:33:04.404 dArt[2351:303] -[NSISRestrictedToNonNegativeVariableToBeMinimized
stringByStandardizingPath]: unrecognized selector sent to instance 0x100528ba0
2013-02-12 19:33:04.405 dArt[2351:303] -[NSISRestrictedToNonNegativeVariableToBeMinimized
stringByStandardizingPath]: unrecognized selector sent to instance 0x100528ba0

2013-02-12 19:33:04.408 dArt[2351:303] (
    0   CoreFoundation                      0x00007fff862c40a6 __exceptionPreprocess + 198
    1   libobjc.A.dylib                     0x00007fff8d4e53f0 objc_exception_throw + 43
    2   CoreFoundation                      0x00007fff8635a6ea -[NSObject(NSObject) doesNotRecognizeSelector:] + 186
    3   CoreFoundation                      0x00007fff862b25ce ___forwarding___ + 414
    4   CoreFoundation                      0x00007fff862b23b8 _CF_forwarding_prep_0 + 232
    5   dArt                                0x000000010000248d -[AppDelegate searchTheArt:] + 141
    6   AppKit                              0x00007fff8a91ea59 -[NSApplication sendAction:to:from:] + 342
    7   AppKit                              0x00007fff8a91e8b7 -[NSControl sendAction:to:] + 85
    8   AppKit                              0x00007fff8a91e7eb -[NSCell _sendActionFrom:] + 138
    9   AppKit                              0x00007fff8a91ccd3 -[NSCell trackMouse:inRect:ofView:untilMouseUp:] + 1855
    10  AppKit                              0x00007fff8a91c521 -[NSButtonCell trackMouse:inRect:ofView:untilMouseUp:] + 504
    11  AppKit                              0x00007fff8a91bc9c -[NSControl mouseDown:] + 820
    12  AppKit                              0x00007fff8a91360e -[NSWindow sendEvent:] + 6853
    13  AppKit                              0x00007fff8a90f744 -[NSApplication sendEvent:] + 5761
    14  AppKit                              0x00007fff8a8252fa -[NSApplication run] + 636
    15  AppKit                              0x00007fff8a7c9cb6 NSApplicationMain + 869
    16  dArt                                0x00000001000016b2 main + 34
    17  libdyld.dylib                       0x00007fff8b36b7e1 start + 0
)

Answer 1

我的问题已在其他地方得到解答。我只需要将(copy)限定符添加到theDownloadLocation属性。

赞@property (copy) NSString *theDownloadLocation;

方法适用于applicationDidFinishLaunching，但不适用于其他方法（在同一文件中）！

1 个答案: