xcode - 「stringByAppendingPathComponent」を使用してファイル名を追加できません (Foundation)

Question

ここでの問題は、「stringByAppendingPathComponent」を使用してファイル名を追加できないことです。fma は NSFileManager です。

働く：

[fma changeCurrentDirectoryPath: [NSHomeDirectory() stringByAppendingPathComponent: @"Music/iTunes/iTunes Media/Music/ABC/DEF"]];
NSLog(@"Current Directory Path: %@", [fma currentDirectoryPath]); 

出力: 現在のディレクトリ パス: /Users/plusa/Music/iTunes/iTunes Media/ABC/DEF

動作していません:

[fma changeCurrentDirectoryPath: [NSHomeDirectory() stringByAppendingPathComponent: @"Music/iTunes/iTunes Media/Music/ABC/DEF/a.mp3"]];
NSLog(@"Current Directory Path: %@", [fma currentDirectoryPath]); // No change

---

アップデート

これから行うことは、単純な fileManager を作成することです。

main.m

#import <Foundation/Foundation.h>
#import "fileManager.h"

int main(int argc, const char * argv[])
{

    @autoreleasepool {

        NSLog(@"Welcome to File Manager.");

        fileManager *fma = [[fileManager alloc] init];

        NSLog(@"Current Directory Path: %@", [fma currentDirectoryPath]);
        [fma changeCurrentDirectoryPath: [NSHomeDirectory() stringByAppendingPathComponent: @"Music/iTunes/iTunes Media/Music"]];
        NSLog(@"Directory Path changed to iTunes Music source base");

        [fma readCurrentItem];

    }
    return 0;
}

fileManager.h

#import <Foundation/Foundation.h>

@interface fileManager : NSFileManager {
    NSArray *list;
}

-(int) readCurrentItem;

@end

fileManager.m

#import "fileManager.h"

@implementation fileManager

-(int) readCurrentItem
{
    int i = 1;

    NSLog(@"Current Directory Path: %@", [self currentDirectoryPath]);
    NSLog(@"Reading Directory Path...");

    if(NSFileTypeDirectory == [[self attributesOfItemAtPath: [self currentDirectoryPath] error: nil] objectForKey: @"NSFileType"]) {
        list = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:[self currentDirectoryPath] error: nil];
    } else {
        NSLog(@"File");
        return 0;
    }

    i = 1;
    for (NSString *item in list)
        NSLog(@"Item #%i: %@", i++, item);


    NSLog(@"The item to read:");
    scanf("%i", &i);

    if (i == 0) {
        NSLog(@"Shutdown.");
        return 0;
    }

    [self changeCurrentDirectoryPath: [[self currentDirectoryPath] stringByAppendingPathComponent: [list[(i - 1)] lastPathComponent]]];

    [self readCurrentItem];

}

@end