- (NSString *)dataPath:(NSString *)file  {      NSString *path = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"badge"];      BOOL bo = [[NSFileManager defaultManager] createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:nil];      NSAssert(bo,@"创建目录失败");      NSString *result = [path stringByAppendingPathComponent:file];      return result;  }   - (void)viewDidLoad  {      [super viewDidLoad];       //此处首先指定了图片存取路径（默认写到应用程序沙盒 中）      NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);      //并给文件起个文件名      NSString *imageDir = [[[paths objectAtIndex:0] stringByAppendingPathComponent:@"163"] stringByAppendingPathComponent:@"songzi"];      //存放图片的文件夹      NSString *imagePath =[imageDir stringByAppendingPathComponent:@"文件名.png"];      NSData *data = nil;      //检查图片是否已经保存到本地      if([self isExistsFile:imagePath]){          data=[NSData dataWithContentsOfFile:imagePath];      }else{          data = [NSData dataWithContentsOfURL:[NSURL URLWithString: @"网址"]];          //创建文件夹路径          [[NSFileManager defaultManager] createDirectoryAtPath:imageDir withIntermediateDirectories:YES attributes:nil error:nil];          //创建图片          [UIImagePNGRepresentation([UIImage imageWithData:data]) writeToFile:imagePath atomically:YES];               }      imageView.image = [UIImage imageWithData:data];  } 

NSString *path = [[NSBundle mainBundle] pathForResource:fileName ofType:@""]; if(path==NULL)

NSFileManager *fileManager = [NSFileManager defaultManager];    //Get documents directory    NSArray *directoryPaths = NSSearchPathForDirectoriesInDomains    (NSDocumentDirectory, NSUserDomainMask, YES);    NSString *documentsDirectoryPath = [directoryPaths objectAtIndex:0];    if ([fileManager fileExistsAtPath:@""]==YES) {         NSLog(@"File exists");     }  

//判断文件是否存在     if(![c judgeFileExist:@"user.plist"])           {         NSLog(@"请确认该文件是否存在！");         return;     }

//判断文件是否存在 -(BOOL)judgeFileExist:(NSString * )fileName {     //获取文件路径     NSString *path = [[NSBundle mainBundle] pathForResource:fileName ofType:@""];     if(path==NULL)         return NO;     returnYES; }