C# http Post 方法

摘自: http://geekswithblogs.net/rakker/archive/2006/04/21/76044.aspx

Http Post in C#
Searched out on the internet and didn't really find anything that was horribly succinct, so I wrote this class for fun.  I had help from http://www.codeproject.com/cs/webservices/translation.asp.  I hope you enjoy!  Here's the code to call it:

PostSubmitter post=new PostSubmitter();
post.Url="http://seeker.dice.com/jobsearch/servlet/JobSearch";
post.PostItems.Add("op","");
post.PostItems.Add("rel_code","");
post.PostItems.Add("FREE_TEXT","c# jobs");
post.PostItems.Add("SEARCH","");
post.Type=PostSubmitter.PostTypeEnum.Post;
string result=post.Post();

And here's the class:

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

namespace Snowball.Common
{
/// <summary>
/// Submits post data to a url.
/// </summary>
public class PostSubmitter
{
/// <summary>
/// determines what type of post to perform.
/// </summary>
public enum PostTypeEnum
{
/// <summary>
/// Does a get against the source.
/// </summary>
Get,
/// <summary>
/// Does a post against the source.
/// </summary>
Post
}

private string m_url=string.Empty;
private NameValueCollection m_values=new NameValueCollection();
private PostTypeEnum m_type=PostTypeEnum.Get;
/// <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;
}

/// <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;
}
}
/// <summary>
/// Posts the supplied data to specified url.
/// </summary>
/// <returns>a string containing the result of the post.</returns>
public string Post()
{
StringBuilder parameters=new StringBuilder();
for (int i=;i < m_values.Count;i++)
{
EncodeAndAddItem(ref parameters,m_values.GetKey(i),m_values[i]);
}
string result=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 string Post(string url)
{
m_url=url;
return 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 string Post(string url, NameValueCollection values)
{
m_values=values;
return 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 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 = request.GetRequestStream())
{
UTF8Encoding encoding = new UTF8Encoding();
byte[] bytes = encoding.GetBytes(postData);
writeStream.Write(bytes, , 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) request.GetResponse())
{
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!=)
{
baseRequest.Append("&");
}
baseRequest.Append(key);
baseRequest.Append("=");
baseRequest.Append(System.Web.HttpUtility.UrlEncode(dataItem));
}
}
}