SDWebImage 获取缓存，清除缓存

    //获取缓存

    float tmpSize= [[SDImageCache sharedImageCache] getSize];

    

    NSLog(@"%f",tmpSize);

    self.dataSizeLib.text = [NSString stringWithFormat:@"%.1fM",tmpSize/1024/1024];

    //清楚缓存

    [[SDImageCache sharedImageCache] clearDiskOnCompletion:nil];