//第一種方法： NSFileManager實例方法讀取數據
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDesktopDirectory, NSUserDomainMask, YES);
NSString* thepath = [paths lastObject];
thepath = [thepath stringByAppendingPathComponent:@"fd_list.txt"];
NSLog(@"桌面目錄：%@", thepath);
NSFileManager* fm = [NSFileManager defaultManager];
NSData* data = [[NSData alloc] init];
data = [fm contentsAtPath:thepath];
NSLog(@"%@",[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);

    //第二種方法： NSData類方法讀取數據
    data = [NSData dataWithContentsOfFile:thepath];
    NSLog(@"NSData類方法讀取的內容是：%@",[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);
    
    
    //第三種方法： NSString類方法讀取內容
    NSString* content = [NSString stringWithContentsOfFile:thepath encoding:NSUTF8StringEncoding error:nil];
    NSLog(@"NSString類方法讀取的內容是：\n%@",content);
    
    
    //第四種方法： NSFileHandle實例方法讀取內容
    NSFileHandle* fh = [NSFileHandle fileHandleForReadingAtPath:thepath];
    data = [fh readDataToEndOfFile];
    NSLog(@"NSFileHandle實例讀取的內容是：\n%@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);
}
return 0;

JSON：
NSString * jsonPath = [[NSBundle mainBundle]pathForResource:@"json" ofType:@"json"];
NSData * jsonData = [[NSData alloc]initWithContentsOfFile:jsonPath];

NSMutableDictionary *jsonDic = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingAllowFragments error:nil];

NSArray * list = jsonDic[@"list"];