具有 PostAsync 代码优化的 HttpClient

Question

我正在使用下面的代码，代码运行良好。我是 HTTPClient 的新手，所以我不确定这段代码是否得到了适当的优化，或者什么是最好的编码方式。我发现这个例子讨论了死锁，尽管它是关于并行编程的，但我只是想确保这段代码是否可以针对性能或错误进行改进/优化。

我使用某些关键参数连接到网站并返回 json 数据。我会处理以采取进一步行动。

protected void btnClient_Click(object sender, EventArgs e)
    {
        using (var client = new HttpClient())
        {

            client.BaseAddress = new Uri("https://secure.telr.com/");
            client.DefaultRequestHeaders.ExpectContinue = false;
            var result = client.PostAsync("gateway/order.json",
                new FormUrlEncodedContent(new List<KeyValuePair<string, string>>()
            {
                new KeyValuePair<string, string>("ivp_method", "create"),
                new KeyValuePair<string, string>("ivp_store", "12345"),
                new KeyValuePair<string, string>("ivp_authkey", "xxx-xxxxxx"),
                new KeyValuePair<string, string>("ivp_cart", "123452"),
                new KeyValuePair<string, string>("ivp_desc", "Descripion"),
                new KeyValuePair<string, string>("ivp_test", "1"),
                new KeyValuePair<string, string>("ivp_amount", "10.00"),
                new KeyValuePair<string, string>("ivp_currency", "UAD"),
                new KeyValuePair<string, string>("return_auth", "http://localhost:1044/Test2.aspx"),
                new KeyValuePair<string, string>("return_can", "http://localhost:1044/Test2.aspx"),
                new KeyValuePair<string, string>("return_decl", "http://localhost:1044/Test2.aspx"),
                new KeyValuePair<string, string>("ivp_framed", "1"),
            })).Result;


            var jsonData = (JObject)JsonConvert.DeserializeObject(result.Content.ReadAsStringAsync().Result);

            dynamic jObj = JsonConvert.DeserializeObject(result.Content.ReadAsStringAsync().Result);

            string url = jsonData["order"]["url"].ToString();
            Response.Write("<br>url" + url + "<br>");

            ltrTelr.Text = "<iframe id= 'telr' src='" + url + "' ></iframe>";

        }
    }

Answer 1

当您不确定您的 API 是否/何时返回数据时，您应该避免尝试访问 Task.Result。这会阻止您的线程，因为它正在尝试评估结果。

相反，当您调用异步方法时，您应该使用 'await' 关键字来释放线程，如下所示：

protected async Task btnClient_Click(object sender, EventArgs e)
{
    using (var client = new HttpClient())
    {

        client.BaseAddress = new Uri("https://secure.telr.com/");
        client.DefaultRequestHeaders.ExpectContinue = false;
        var result = await client.PostAsync("gateway/order.json",
            new FormUrlEncodedContent(new List<KeyValuePair<string, string>>()
        {
            new KeyValuePair<string, string>("ivp_method", "create"),
            new KeyValuePair<string, string>("ivp_store", "12345"),
            new KeyValuePair<string, string>("ivp_authkey", "xxx-xxxxxx"),
            new KeyValuePair<string, string>("ivp_cart", "123452"),
            new KeyValuePair<string, string>("ivp_desc", "Descripion"),
            new KeyValuePair<string, string>("ivp_test", "1"),
            new KeyValuePair<string, string>("ivp_amount", "10.00"),
            new KeyValuePair<string, string>("ivp_currency", "UAD"),
            new KeyValuePair<string, string>("return_auth", "http://localhost:1044/Test2.aspx"),
            new KeyValuePair<string, string>("return_can", "http://localhost:1044/Test2.aspx"),
            new KeyValuePair<string, string>("return_decl", "http://localhost:1044/Test2.aspx"),
            new KeyValuePair<string, string>("ivp_framed", "1"),
        }));

        var rawData = await result.Content.ReadAsStringAsync();

        var jsonData = (JObject)JsonConvert.DeserializeObject(rawData);
        dynamic jObj = JsonConvert.DeserializeObject(rawData);

        string url = jsonData["order"]["url"].ToString();
        Response.Write("<br>url" + url + "<br>");

        ltrTelr.Text = "<iframe id= 'telr' src='" + url + "' ></iframe>";

    }
}