iOS-判断沙盒中是否已经存在文件

//判断文件是否已经在沙盒中已经存在？
-(BOOL) isFileExist:(NSString *)fileName
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *path = [paths objectAtIndex:0];
NSString *filePath = [path stringByAppendingPathComponent:fileName];
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL result = [fileManager fileExistsAtPath:filePath];
NSLog(@"这个文件已经存在：%@",result?@"是的":@"不存在");
return result;
}

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);