编写一个函数，实现递归删除指定路径下的所有文件

作品链接：http://www.jianshu.com/users/1e0f5e6f73f6/top_articles

+ (void)deleteFiles:(NSString *)path;{
// 1. 判断文件还是目录
NSFileManager * fileManger = [NSFileManager defaultManager]; 
BOOL isDir = NO;
BOOL isExist = [fileManger fileExistsAtPath:pathisDirectory:&isDir];
// 2.  判断是不是目录
if (isExist) {
    if (isDir) {
 NSArray * dirArray = [fileMangercontentsOfDirectoryAtPath:path error:nil];
 NSString * subPath = nil;
        for (NSString * str in dirArray) {
 subPath = [pathstringByAppendingPathComponent:str];
 BOOL issubDir = NO; 
[fileManger fileExistsAtPath:subPath isDirectory:&issubDir];
 [self deleteFiles:subPath];
                }
 }else{ NSLog(@"%@",path);
 [manager removeItemAtPath:filePath error:nil];
       }
}else{
NSLog(@"你打印的是目录或者是不存在 ");
      }
}