Objective-C：從NSString製作NSArray

Question

我試圖從文件路徑組件創建一個數組。我的文件路徑的數組（如NSString的），我通過他們循環，再破每下跌，像這樣：

//get the array of image paths 
imageList = [[notification userInfo] objectForKey:@"images"]; 

//loop through the array and get the image names 
for (NSString* thisImagePath in imageList) { 
    NSArray* thisImagePathArray = [thisImagePath componentsSeparatedByString:@"/"]; 

可以說，我計劃在這裏崩潰的時間。我收到以下錯誤消息：

-[NSCFArray componentsSeparatedByString:]: unrecognized selector sent to instance 0x1a7940 

imageList是放入視圖的文件數組。因爲這個問題開始出現，我一次只刪除一個文件。例如：

這個文件沒有工作：

/Users/steve/Desktop/thinkstock/PT121211_PI_bariatric.tif 

這確實

/Users/steve/Desktop/thinkstock/Studentexhausted82557038.jpg 

所以，如果我理解正確的錯誤消息，我想給componentsSeparatedByString選擇應用到一個NSArray，不支持該選擇器。但在我的循環中，我正在調用NSString，如果對象是一個數組，我不應該在那裏崩潰？ （並且我99％確定imageList的索引0處的對象是一個字符串。）

我的目標是從文件路徑獲取文件名，有沒有比我採用的方法更好的方法？

當我通過（把一個調試點似乎工作，我策劃了componentsSeparatedByString線步驟：

但如果我打繼續它崩潰

至於建議我改變。我的代碼來記錄數據：

//loop through the array and get the image names 
for (NSString* thisImagePath in imageList) { 
if (![thisImagePath isKindOfClass:[NSString class]]) { 
    NSLog(@"The class of this object is: %@", [thisImagePath className]); 
} 
NSLog(@"%@", thisImagePath); 

NSArray* thisImagePathArray = [thisImagePath componentsSeparatedByString:@"/"]; 
NSString* thisImageName = [thisImagePathArray objectAtIndex:[thisImagePathArray count]-1]; 

類檢查的條件永遠不會被觸發，因爲一切都是NSS特級。然而，一些文件的工作，一些不...

2012-01-19 13:59:04.631 archiveDrop_cocoa[76758:10b] /Users/steve/Desktop/thinkstock/rbrb_0556.jpg 
2012-01-19 13:59:06.799 archiveDrop_cocoa[76758:10b] /Users/steve/Desktop/thinkstock/Manracefinish78464007.jpg 
2012-01-19 13:59:08.319 archiveDrop_cocoa[76758:10b] /Users/steve/Desktop/thinkstock/ManLabtop86510699.jpg 
2012-01-19 13:59:08.320 archiveDrop_cocoa[76758:10b] *** -[NSCFArray componentsSeparatedByString:]: unrecognized selector sent to instance 0x1a75c0 
2012-01-19 13:59:08.321 archiveDrop_cocoa[76758:10b] *** Canceling drag because exception 'NSInvalidArgumentException' (reason '*** -[NSCFArray componentsSeparatedByString:]: unrecognized selector sent to instance 0x1a75c0') was raised during a dragging session 
2012-01-19 13:59:10.726 archiveDrop_cocoa[76758:10b] /Users/steve/Desktop/thinkstock/LasVegassign78058995.jpg 
2012-01-19 13:59:10.728 archiveDrop_cocoa[76758:10b] *** -[NSCFArray componentsSeparatedByString:]: unrecognized selector sent to instance 0x1a9010 
2012-01-19 13:59:10.729 archiveDrop_cocoa[76758:10b] *** Canceling drag because exception 'NSInvalidArgumentException' (reason '*** -[NSCFArray componentsSeparatedByString:]: unrecognized selector sent to instance 0x1a9010') was raised during a dragging session 
2012-01-19 13:59:13.342 archiveDrop_cocoa[76758:10b] /Users/steve/Desktop/thinkstock/kidscolor57448860.jpg 
2012-01-19 13:59:15.014 archiveDrop_cocoa[76758:10b] /Users/steve/Desktop/thinkstock/IVDrip76801701.jpg 
2012-01-19 13:59:18.263 archiveDrop_cocoa[76758:10b] /Users/steve/Desktop/thinkstock/stk26719pin.jpg 
2012-01-19 13:59:23.414 archiveDrop_cocoa[76758:10b] /Users/steve/Desktop/thinkstock/WomanLabtop78634274.jpg 

Answer 1

當你100％確定你真的在這裏得到一個NSString時，爲什麼不使用[thisImagePath lastPathComponent]？

http://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSString_Class/Reference/NSString.html#//apple_ref/occ/instm/NSString/lastPathComponent

Answer 2

您的圖像列表中的一個條目是一個NSArray。你需要弄清楚爲什麼。

Answer 3

你可能想看看NSString's -lastPathComponent或-pathComponents而不是調用-componentsSeparatedByString:因爲它們將可靠地解析路徑。

像熱舔建議，它看起來像你試圖撥打電話-componentsSeparatedByStringNSArray。我會NSLog(@"imageList: %@", imageList)幾個樣本文件滴，看看你做了什麼，或者可能裏面的for循環

if (![thisImagePath isKindOfClass:[NSString class]) NSLog(@"Not a String: %@", thisImagePath);