删除缓存

   //    寻找地址
        NSString * path = [NSHomeDirectory() stringByAppendingString:@"/Library/Caches"];
        //    文件管理者
        NSFileManager *fileManager = [NSFileManager defaultManager] ;

        

                NSDictionary * dict = [fileManager attributesOfItemAtPath:path error:nil];
        //    提示框
        UIAlertController *alertC = [UIAlertController alertControllerWithTitle:[NSString stringWithFormat:@"缓存共有%.2f M", ([[dict objectForKey:NSFileSize]/**  <-文件大小 ||  转换成数字 -> **/ doubleValue] / 1024.0 )] message:@"要清除么?" preferredStyle:UIAlertControllerStyleAlert];
       
        [alertC addAction:[UIAlertAction actionWithTitle:@"确认" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
           
            if ([fileManager fileExistsAtPath:path]) {
                NSArray *childerFiles=[fileManager subpathsAtPath:path];
                for (NSString *fileName in childerFiles) {
                    //如有需要，加入条件，过滤掉不想删除的文件
                    NSString *absolutePath=[path stringByAppendingPathComponent:fileName];
                    //    删除文件
                    [fileManager removeItemAtPath:absolutePath error:nil];
                }
            }
            //   清除SDWebImage缓存图片
            [[SDImageCache sharedImageCache] cleanDisk];
           
        }]];
        [alertC addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

          //   不作任何动作  

        }]];
        [self presentViewController:alertC animated:YES completion:^{

           //   添加到VC的View上 

        }];