【发布时间】：2015-07-24 03:56:23
【问题描述】：
我的应用程序从 NSOpenPanel 获取路径，并从路径获取 nsdata 对象，从路径获取 nsstring 对象。然后我去调用 [filePath lastPathComponent]; （filePath 是路径中的 NSString 对象）。它使我的应用程序崩溃并给我错误：
2015-05-12 20:11:46.022 myApp[409:303] -[__NSCFData lastPathComponent]: unrecognized selector sent to instance 0x100528920
2015-05-12 20:11:46.022 myApp[409:303] An uncaught exception was raised
2015-05-12 20:11:46.022 myApp[409:303] -[__NSCFData lastPathComponent]: unrecognized selector sent to instance 0x100528920
2015-05-12 20:11:46.028 myApp[409:303] (
0 CoreFoundation 0x00007fff8d35ff56 __exceptionPreprocess + 198
1 libobjc.A.dylib 0x00007fff93119d5e objc_exception_throw + 43
2 CoreFoundation 0x00007fff8d3ec1be -[NSObject doesNotRecognizeSelector:] + 190
3 CoreFoundation 0x00007fff8d34ce23 ___forwarding___ + 371
4 CoreFoundation 0x00007fff8d34cc38 _CF_forwarding_prep_0 + 232
5 myApp 0x00000001000030cc -[MPOMainWindowController tableView:objectValueForTableColumn:row:] + 140
6 AppKit 0x00007fff8aa7d6e7 -[NSTableView _dataSourceValueForColumn:row:] + 73
7 AppKit 0x00007fff8aa7d167 -[NSTableView preparedCellAtColumn:row:] + 437
8 AppKit 0x00007fff8aa8e171 -[NSTableView _drawContentsAtRow:column:withCellFrame:] + 42
9 AppKit 0x00007fff8aa8c5d8 -[NSTableView drawRow:clipRect:] + 1647
10 AppKit 0x00007fff8aa8bdb5 -[NSTableView drawRowIndexes:clipRect:] + 565
11 AppKit 0x00007fff8aa89ed7 -[NSTableView drawRect:] + 1390
12 AppKit 0x00007fff8a9f22ce -[NSView _drawRect:clip:] + 3758
13 AppKit 0x00007fff8aa1f49b -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 1583
14 AppKit 0x00007fff8aa1f8c7 -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 2651
15 AppKit 0x00007fff8aa1f8c7 -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 2651
16 AppKit 0x00007fff8aa1f8c7 -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 2651
17 AppKit 0x00007fff8aa1f8c7 -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 2651
18 AppKit 0x00007fff8a9ef8a9 -[NSView _recursiveDisplayRectIfNeededIgnoringOpacity:isVisibleRect:rectIsVisibleRectForView:topView:] + 1032
19 AppKit 0x00007fff8a9eeda3 -[NSThemeFrame _recursiveDisplayRectIfNeededIgnoringOpacity:isVisibleRect:rectIsVisibleRectForView:topView:] + 270
20 AppKit 0x00007fff8a9ea1bb -[NSView _displayRectIgnoringOpacity:isVisibleRect:rectIsVisibleRectForView:] + 4755
21 AppKit 0x00007fff8a9e2c35 -[NSView displayIfNeeded] + 1676
22 AppKit 0x00007fff8aaa02fb -[NSWindow _reallyDoOrderWindow:relativeTo:findKey:forCounter:force:isModal:] + 1306
23 AppKit 0x00007fff8aa9fcf8 -[NSWindow _doOrderWindow:relativeTo:findKey:forCounter:force:isModal:] + 807
24 AppKit 0x00007fff8aa9f97c -[NSWindow orderWindow:relativeTo:] + 154
25 AppKit 0x00007fff8a9b847e -[NSIBObjectData nibInstantiateWithOwner:topLevelObjects:] + 1556
26 AppKit 0x00007fff8a9ae8bb loadNib + 322
27 AppKit 0x00007fff8a9addb8 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:withZone:ownerBundle:] + 217
28 AppKit 0x00007fff8a9adcd3 +[NSBundle(NSNibLoading) loadNibFile:externalNameTable:withZone:] + 141
29 AppKit 0x00007fff8a9adc16 +[NSBundle(NSNibLoading) loadNibNamed:owner:] + 364
30 AppKit 0x00007fff8ac1ecd7 NSApplicationMain + 398
31 myApp 0x0000000100001412 main + 34
32 myApp 0x00000001000013e4 start + 52
33 ??? 0x0000000000000003 0x0 + 3
)
2015-05-12 20:11:46.029 myApp[409:303] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFData lastPathComponent]: unrecognized selector sent to instance 0x100528920'
*** First throw call stack:
(
0 CoreFoundation 0x00007fff8d35ff56 __exceptionPreprocess + 198
1 libobjc.A.dylib 0x00007fff93119d5e objc_exception_throw + 43
2 CoreFoundation 0x00007fff8d3ec1be -[NSObject doesNotRecognizeSelector:] + 190
3 CoreFoundation 0x00007fff8d34ce23 ___forwarding___ + 371
4 CoreFoundation 0x00007fff8d34cc38 _CF_forwarding_prep_0 + 232
5 myApp 0x00000001000030cc -[MPOMainWindowController tableView:objectValueForTableColumn:row:] + 140
6 AppKit 0x00007fff8aa7d6e7 -[NSTableView _dataSourceValueForColumn:row:] + 73
7 AppKit 0x00007fff8aa7d167 -[NSTableView preparedCellAtColumn:row:] + 437
8 AppKit 0x00007fff8aa8e171 -[NSTableView _drawContentsAtRow:column:withCellFrame:] + 42
9 AppKit 0x00007fff8aa8c5d8 -[NSTableView drawRow:clipRect:] + 1647
10 AppKit 0x00007fff8aa8bdb5 -[NSTableView drawRowIndexes:clipRect:] + 565
11 AppKit 0x00007fff8aa89ed7 -[NSTableView drawRect:] + 1390
12 AppKit 0x00007fff8a9f22ce -[NSView _drawRect:clip:] + 3758
13 AppKit 0x00007fff8aa1f49b -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 1583
14 AppKit 0x00007fff8aa1f8c7 -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 2651
15 AppKit 0x00007fff8aa1f8c7 -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 2651
16 AppKit 0x00007fff8aa1f8c7 -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 2651
17 AppKit 0x00007fff8aa1f8c7 -[NSView _recursiveDisplayAllDirtyWithLockFocus:visRect:] + 2651
18 AppKit 0x00007fff8a9ef8a9 -[NSView _recursiveDisplayRectIfNeededIgnoringOpacity:isVisibleRect:rectIsVisibleRectForView:topView:] + 1032
19 AppKit 0x00007fff8a9eeda3 -[NSThemeFrame _recursiveDisplayRectIfNeededIgnoringOpacity:isVisibleRect:rectIsVisibleRectForView:topView:] + 270
20 AppKit 0x00007fff8a9ea1bb -[NSView _displayRectIgnoringOpacity:isVisibleRect:rectIsVisibleRectForView:] + 4755
21 AppKit 0x00007fff8a9e2c35 -[NSView displayIfNeeded] + 1676
22 AppKit 0x00007fff8aaa02fb -[NSWindow _reallyDoOrderWindow:relativeTo:findKey:forCounter:force:isModal:] + 1306
23 AppKit 0x00007fff8aa9fcf8 -[NSWindow _doOrderWindow:relativeTo:findKey:forCounter:force:isModal:] + 807
24 AppKit 0x00007fff8aa9f97c -[NSWindow orderWindow:relativeTo:] + 154
25 AppKit 0x00007fff8a9b847e -[NSIBObjectData nibInstantiateWithOwner:topLevelObjects:] + 1556
26 AppKit 0x00007fff8a9ae8bb loadNib + 322
27 AppKit 0x00007fff8a9addb8 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:withZone:ownerBundle:] + 217
28 AppKit 0x00007fff8a9adcd3 +[NSBundle(NSNibLoading) loadNibFile:externalNameTable:withZone:] + 141
29 AppKit 0x00007fff8a9adc16 +[NSBundle(NSNibLoading) loadNibNamed:owner:] + 364
30 AppKit 0x00007fff8ac1ecd7 NSApplicationMain + 398
31 myApp 0x0000000100001412 main + 34
32 myApp 0x00000001000013e4 start + 52
33 ??? 0x0000000000000003 0x0 + 3
)
terminate called throwing an exception(lldb)
我不明白为什么这不起作用，因为大约 2 小时前我正在研究它时它起作用了。有人有什么建议吗？
编辑：这是我的代码：
NSOpenPanel *panel = [NSOpenPanel openPanel];
// display the panel
[panel beginWithCompletionHandler:^(NSInteger result) {
if (result == NSFileHandlingPanelOKButton) {
[[webView mainFrame] loadRequest:nil];
// grab a reference to what has been selected
NSURL *fileURL = [[panel URLs]objectAtIndex:0];
// write our file name to a label
NSString *filePath = [NSString stringWithFormat:@"%@", fileURL];
NSString *fileName = [filePath lastPathComponent]; // <-- Error is here I think
【问题讨论】：
-
您显然是在
NSData对象上调用-lastPathComponent，而不是字符串。您需要出示您的代码。 -
寻求调试帮助的问题（“为什么这段代码不起作用？”）必须包括所需的行为、特定的问题或错误以及在问题本身中重现它所需的最短代码。跨度>
-
该错误似乎并非来自该行代码。我猜那行不是
[MPOMainWindowController tableView:objectValueForTableColumn:row:] + 140。 （虽然你有一点机会因为“僵尸”而出现问题。） -
（愚蠢的问题：您是否在上面发布的代码的最后两行之间省略了一些代码？）
标签： objective-c macos cocoa nsstring runtime-error