C# WebHTTPUtil工具类

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Net;
using System.IO;
using System.Text.RegularExpressions;
public class WebHTTPUtil
{
	public CookieContainer CookieContainer { get; set; }
	public CookieCollection CookieCollection { get; set; }
	public WebRequest Request{
		get; set;
	}

	public WebHTTPUtil()
	{
		this.CookieCollection = new CookieCollection();
		this.CookieContainer = new CookieContainer();
	}

	/// <summary>
	/// 以POST 形式请求数据
	/// </summary>
	/// <param name="RequestPara"></param>
	/// <param name="Url"></param>
	/// <returns></returns>
	public  string PostData(string Url,string RequestPara)
	{
		System.GC.Collect ();
		Request = HttpWebRequest.Create(Url);
		RequestPara=Regex.Replace(RequestPara,"%", "%25");
		byte[] buf = System.Text.Encoding.GetEncoding("utf-8").GetBytes(RequestPara);
		Request.ContentType = "application/x-www-form-urlencoded";
		Request.ContentLength = buf.Length;
		Request.Method = "POST";

		System.IO.Stream RequestStream = Request.GetRequestStream();
		RequestStream.Write(buf, 0, buf.Length);
		RequestStream.Close();

		System.Net.WebResponse response = Request.GetResponse();
		StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("utf-8"));
		string ReturnVal = reader.ReadToEnd();
		reader.Close();
		response.Close();
		Request = null;
		return ReturnVal;
	}

	/// <summary>
	/// 以GET 形式获取数据
	/// </summary>
	/// <param name="RequestPara"></param>
	/// <param name="Url"></param>
	/// <returns></returns>

	public  string GetData(string Url, string RequestPara)
	{
		System.GC.Collect ();
		RequestPara=RequestPara.IndexOf('?')>-1?(RequestPara):("?"+RequestPara);
		RequestPara=Regex.Replace(RequestPara,"%", "%25");
		Request = HttpWebRequest.Create(Url + RequestPara);

		byte[] buf = System.Text.Encoding.GetEncoding("utf-8").GetBytes(RequestPara);
		Request.Method = "GET";

		System.Net.WebResponse response = Request.GetResponse();
		string status = ((HttpWebResponse)response).StatusDescription;
		if (!status.Equals ("OK")) {
			response.Close();
			return "ERROR";
		}
		StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("utf-8"));

		string ReturnVal = reader.ReadToEnd();
		reader.Close();
		response.Close();
		Request = null;
		return ReturnVal;
	}

}