诡异的HttpClient

最近因为生成一个url二维码发现了C#HttpClient诡异的地方，先贴出代码：

private static async Task<string> GetShortUrlAsync(string url)
        {
            var client = new HttpClient();
            client.DefaultRequestHeaders.Add("Token", "xxxxxx");
            client.DefaultRequestHeaders.Add("ContentType", "application/json; charset=UTF-8");
            var param = JsonConvert.SerializeObject(new { url });
            var task = client.PostAsync("https://dwz.cn/admin/v2/create", new StringContent(param, Encoding.UTF8));
            task.Wait();
            var response = task.Result;
            //var response = await client.PostAsync("https://dwz.cn/admin/v2/create", new StringContent(param, Encoding.UTF8));  //卡在这里
            var json = await response.Content.ReadAsStringAsync();
            var result = JsonConvert.DeserializeAnonymousType(json, new
            {
                Code = 0,
                ShortUrl = string.Empty,
                LongUrl = string.Empty,
                ErrMsg = string.Empty
            });
            if (!string.IsNullOrEmpty(result.ErrMsg))
            {
                throw new Exception(result.ErrMsg);
            }
            return result.ShortUrl;
        }

以上代码就是调用百度转短连接的API,就在异步获取Response的时候一直卡着不动，用task.Wait()再取task.Result就没问题，await语法以前用得很少，还请各位大神赐教