Objective-C：从NSString制作NSArray

Question

我试图从文件路径组件创建一个数组。我的文件路径的数组（如NSString的），我通过他们循环，再破每下跌，像这样：

//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:@"/"]; 

可以说，我计划在这里崩溃的时间。我收到以下错误消息：

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

imageList是放入视图的文件数组。因为这个问题开始出现，我一次只删除一个文件。例如：

这个文件没有工作：

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

这确实

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

所以，如果我理解正确的错误消息，我想给componentsSeparatedByString选择应用到一个NSArray，不支持该选择器。但在我的循环中，我正在调用NSString，如果对象是一个数组，我不应该在那里崩溃？ （并且我99％确定imageList的索引0处的对象是一个字符串。）

我的目标是从文件路径获取文件名，有没有比我采用的方法更好的方法？

当我通过（把一个调试点似乎工作，我策划了componentsSeparatedByString线步骤：

但如果我打继续它崩溃

至于建议我改变。我的代码来记录数据：

//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]; 

类检查的条件永远不会被触发，因为一切都是NSS特级。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

当你100％确定你真的在这里得到一个NSString时，为什么不使用[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

您的图像列表中的一个条目是一个NSArray。你需要弄清楚为什么。

Answer 3

你可能想看看NSString's -lastPathComponent或-pathComponents而不是调用-componentsSeparatedByString:因为它们将可靠地解析路径。

像热舔建议，它看起来像你试图拨打电话-componentsSeparatedByStringNSArray。我会NSLog(@"imageList: %@", imageList)几个样本文件滴，看看你做了什么，或者可能里面的for循环

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