C# 后提交者的异步CTP

我正在尝试使用异步CTP构建REST客户机。我是CTP的新手，因此，在浏览了互联网上的许多示例后，我得到了一个只用于发布（GET或POST）的clas。以下是到目前为止的课程：

using System;
using System.Collections.Specialized;
using System.IO;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Web;

namespace RESTClient.Core {

    /// <summary>
    /// Submits post data to a url.
    /// </summary>
    public class PostSubmitter {

        #region Backing Store
        private string m_url = string.Empty;
        private NameValueCollection m_values = new NameValueCollection();
        private PostTypeEnum m_type = PostTypeEnum.Get;
        #endregion

        #region Constructors
        /// <summary>
        /// Default constructor.
        /// </summary>
        public PostSubmitter() {

        }

        /// <summary>
        /// Constructor that accepts a url as a parameter
        /// </summary>
        /// <param name="url">The url where the post will be submitted to.</param>
        public PostSubmitter(string url)
            : this() {
            m_url = url;
        }

        /// <summary>
        /// Constructor allowing the setting of the url and items to post.
        /// </summary>
        /// <param name="url">the url for the post.</param>
        /// <param name="values">The values for the post.</param>
        public PostSubmitter(string url, NameValueCollection values)
            : this(url) {
            m_values = values;
        }
        #endregion

        #region Properties
        /// <summary>
        /// Gets or sets the url to submit the post to.
        /// </summary>
        public string Url {
            get {
                return m_url;
            }
            set {
                m_url = value;
            }
        }

        /// <summary>
        /// Gets or sets the name value collection of items to post.
        /// </summary>
        public NameValueCollection PostItems {
            get {
                return m_values;
            }
            set {
                m_values = value;
            }
        }

        /// <summary>
        /// Gets or sets the type of action to perform against the url.
        /// </summary>
        public PostTypeEnum Type {
            get {
                return m_type;
            }
            set {
                m_type = value;
            }
        }
        #endregion

        /// <summary>
        /// Posts the supplied data to specified url.
        /// </summary>
        /// <returns>a string containing the result of the post.</returns>
        public async Task<String> Post() {
            StringBuilder parameters = new StringBuilder();
            for (int i = 0; i < m_values.Count; i++) {
                EncodeAndAddItem(ref parameters, m_values.GetKey(i), m_values[i]);
            }
            string result = await PostData(m_url, parameters.ToString());
            return result;
        }

        /// <summary>
        /// Posts the supplied data to specified url.
        /// </summary>
        /// <param name="url">The url to post to.</param>
        /// <returns>a string containing the result of the post.</returns>
        public async Task<String> Post(string url) {
            m_url = url;
            return await this.Post();
        }

        /// <summary>
        /// Posts the supplied data to specified url.
        /// </summary>
        /// <param name="url">The url to post to.</param>
        /// <param name="values">The values to post.</param>
        /// <returns>a string containing the result of the post.</returns>
        public async Task<String> Post(string url, NameValueCollection values) {
            m_values = values;
            return await this.Post(url);
        }

        /// <summary>
        /// Posts data to a specified url. Note that this assumes that you have already url encoded the post data.
        /// </summary>
        /// <param name="postData">The data to post.</param>
        /// <param name="url">the url to post to.</param>
        /// <returns>Returns the result of the post.</returns>
        private async Task<String> PostData(string url, string postData) {
            HttpWebRequest request = null;
            if (m_type == PostTypeEnum.Post) {
                Uri uri = new Uri(url);
                request = (HttpWebRequest)WebRequest.Create(uri);
                request.Method = "POST";
                request.ContentType = "application/x-www-form-urlencoded";
                request.ContentLength = postData.Length;
                using (Stream writeStream = await request.GetRequestStreamAsync()) {
                    UTF8Encoding encoding = new UTF8Encoding();
                    byte[] bytes = encoding.GetBytes(postData);
                    writeStream.Write(bytes, 0, bytes.Length);
                }
            }
            else {
                Uri uri = new Uri(url + "?" + postData);
                request = (HttpWebRequest)WebRequest.Create(uri);
                request.Method = "GET";
            }

            string result = string.Empty;

            using (HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync()) {
                using (Stream responseStream = response.GetResponseStream()) {
                    using (StreamReader readStream = new StreamReader(responseStream, Encoding.UTF8)) {
                        result = readStream.ReadToEnd();
                    }
                }
            }

            return result;
        }

        /// <summary>
        /// Encodes an item and ads it to the string.
        /// </summary>
        /// <param name="baseRequest">The previously encoded data.</param>
        /// <param name="dataItem">The data to encode.</param>
        /// <returns>A string containing the old data and the previously encoded data.</returns>
        private void EncodeAndAddItem(ref StringBuilder baseRequest, string key, string dataItem) {
            if (baseRequest == null) {
                baseRequest = new StringBuilder();
            }
            if (baseRequest.Length != 0) {
                baseRequest.Append("&");
            }
            baseRequest.Append(key);
            baseRequest.Append("=");
            baseRequest.Append(HttpUtility.UrlEncode(dataItem));
        }

    }

}

尝试以下方法：

private async void ButtonSubmit_Click(object sender, EventArgs e) {

        ButtonReset.Enabled = false;
        TextResponse.Text = String.Empty;
        TextResponse.Text += "Begining..." + Environment.NewLine;

        TextResponse.Text += await PostSomeData();
        TextResponse.Text += Environment.NewLine;
        TextResponse.Text += "Function Done!" + Environment.NewLine;

}

---

您需要在客户端中使用

async

和

wait

关键字。改变这两行，你应该很好：

private void ButtonSubmit_Click(object sender, EventArgs e) {
=>
private async void ButtonSubmit_Click(object sender, EventArgs e) {

TextResponse.Text += Task.Factory.StartNew(() => PostSomeData().Wait());
=>
TextResponse.Text += await PostSomeData();

---

您的代码只是部分异步的；请仔细查看

PostData

特别是，

ReadToEnd

需要异步：

private async Task<String> PostData(string url, string postData)
{
  HttpWebRequest request = null;
  if (m_type == PostTypeEnum.Post)
  {
    Uri uri = new Uri(url);
    request = (HttpWebRequest)WebRequest.Create(uri);
    request.Method = "POST";
    request.ContentType = "application/x-www-form-urlencoded";
    request.ContentLength = postData.Length;
    using (Stream writeStream = await request.GetRequestStreamAsync())
    {
      UTF8Encoding encoding = new UTF8Encoding();
      byte[] bytes = encoding.GetBytes(postData);
      await writeStream.WriteAsync(bytes, 0, bytes.Length);
    }
  }
  else
  {
    Uri uri = new Uri(url + "?" + postData);
    request = (HttpWebRequest)WebRequest.Create(uri);
    request.Method = "GET";
  }

  using (HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync())
  using (Stream responseStream = response.GetResponseStream())
  using (StreamReader readStream = new StreamReader(responseStream, Encoding.UTF8))
  {
    return await readStream.ReadToEndAsync();
  }
}

private async Task PostData（字符串url，字符串PostData）
{
HttpWebRequest请求=null；
if（m_type==PostTypeEnum.Post）
{
Uri=新的Uri（url）；
request=（HttpWebRequest）WebRequest.Create（uri）；
request.Method=“POST”；
request.ContentType=“application/x-www-form-urlencoded”；
request.ContentLength=postData.Length；
使用（Stream writeStream=wait request.GetRequestStreamAsync（））
{
UTF8Encoding=新的UTF8Encoding（）；
字节[]字节=编码.GetBytes（postData）；
wait writeStream.WriteAsync（字节，0，字节.长度）；
}
}
其他的
{
Uri=新Uri（url+“？”+postData）；
request=（HttpWebRequest）WebRequest.Create（uri）；
request.Method=“GET”；
}
使用（HttpWebResponse=（HttpWebResponse）wait request.GetResponseAsync（））
使用（Stream responseStream=response.GetResponseStream（））
使用（streamreadstream=newstreamreader（responseStream，Encoding.UTF8））
{
返回wait wait readStream.ReadToEndAsync（）；
}
}

---

正如其他人所提到的，这是除了使事件处理程序异步之外的另一项功能。

这确实解决了这个问题。但是，仅当类型为GET时。此外，用户界面frooze。我不能让用户界面冻结。。。有什么建议吗？仅供参考，

m

变量前缀被认为在.NET命名中使用是错误的。^完全同意。这是一些小朋友写的。一旦我把事情弄清楚，我就解雇他。他只是高兴地回家说“一切都结束了”。。。我想知道为什么UI挂起了？好的。似乎包括POST方法在内的一切都在运行。谢谢

private void ButtonSubmit_Click(object sender, EventArgs e) {
=>
private async void ButtonSubmit_Click(object sender, EventArgs e) {

TextResponse.Text += Task.Factory.StartNew(() => PostSomeData().Wait());
=>
TextResponse.Text += await PostSomeData();

private async Task<String> PostData(string url, string postData)
{
  HttpWebRequest request = null;
  if (m_type == PostTypeEnum.Post)
  {
    Uri uri = new Uri(url);
    request = (HttpWebRequest)WebRequest.Create(uri);
    request.Method = "POST";
    request.ContentType = "application/x-www-form-urlencoded";
    request.ContentLength = postData.Length;
    using (Stream writeStream = await request.GetRequestStreamAsync())
    {
      UTF8Encoding encoding = new UTF8Encoding();
      byte[] bytes = encoding.GetBytes(postData);
      await writeStream.WriteAsync(bytes, 0, bytes.Length);
    }
  }
  else
  {
    Uri uri = new Uri(url + "?" + postData);
    request = (HttpWebRequest)WebRequest.Create(uri);
    request.Method = "GET";
  }

  using (HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync())
  using (Stream responseStream = response.GetResponseStream())
  using (StreamReader readStream = new StreamReader(responseStream, Encoding.UTF8))
  {
    return await readStream.ReadToEndAsync();
  }
}