C# .Net WebClient http及https請求

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Web;

namespace Tools
{
    
 
public class RestfullRequest
    {
        public static string Request(string url, string method, string contentType, string data, NameValueCollection header=null,NetworkCredential credential=null,
            string proxyAddress = null, Encoding responseEncoding= null)
        {
            var request = (HttpWebRequest)WebRequest.Create(url);
            
 
if (url.StartsWith("https://"))
            {
                ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(RemoteCertificateValidate);//驗證伺服器證書回撥自動驗證
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
            }
            request.Method 
 
= method;
            if (!string.IsNullOrEmpty(contentType))
                request.ContentType = contentType;
            if (header != null)
                request.Headers.Add(header);
            if (credential != null)
                request.Credentials = credential;

            if (!string.IsNullOrEmpty(proxyAddress))
            {
                IWebProxy proxy = new WebProxy(proxyAddress);
                proxy.Credentials = new NetworkCredential();
                request.Proxy = proxy;
            }

            if (!string.IsNullOrEmpty(data))
            {
                using (var swt = new StreamWriter(request.GetRequestStream()))
                {
                    swt.Write(data);
                }
            }

            string result = string.Empty;
            using (WebResponse response = request.GetResponse())
            {
                if (response.ContentType.IndexOf("octet-stream") > -1)
                {
                    string dispositionStr = response.Headers["Content-Disposition"];
                    int fileNameI = dispositionStr.IndexOf("filename=");
                    string fileName = dispositionStr.Substring(fileNameI + 9, dispositionStr.Length - (fileNameI + 9));
                    fileName = HttpUtility.UrlDecode(fileName, Encoding.UTF8);
                    string downpath = AppDomain.CurrentDomain.BaseDirectory + "Download";
                    if (!Directory.Exists(downpath)) {
                        Directory.CreateDirectory(downpath);
                    }
                    string downFile= downpath + "\\" + fileName;

                    if (File.Exists(downFile))
                    {
                        File.Delete(downFile);
                    }
                    Stream inStream = response.GetResponseStream();
                    using (Stream outStream = File.OpenWrite(downFile)) {
                        byte[] buffer = new byte[8192];
                        int size = 0;
                        while ((size = inStream.Read(buffer, 0, 8192)) > 0)
                        {
                            outStream.Write(buffer, 0, size);
                        }
                    }
                    result = downFile;
                }
                else {
                    Stream stream = response.GetResponseStream();
                    if (responseEncoding == null) responseEncoding = Encoding.UTF8;
                    StreamReader myStreamReader = new StreamReader(stream, responseEncoding);
                    result = myStreamReader.ReadToEnd();
                    myStreamReader.Close();
                    stream.Close();
                    //byte[] buf = new byte[1024];
                    //while (true)
                    //{
                    //    int len = stream.Read(buf, 0, buf.Length);
                    //    if (len <= 0)//len <= 0 跳出迴圈
                    //        break;
                    //    if (responseEncoding == null) responseEncoding = Encoding.UTF8;
                    //     result += responseEncoding.GetString(buf, 0, len);//指定編碼格式
                    //}
                }
                //using (var sr = new StreamReader(response.GetResponseStream()))
                //{
                //    result = sr.ReadToEnd();
                //}
            }
            
            return result;
        }

        private static bool RemoteCertificateValidate(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors error)
        {
            //為了通過證書驗證，總是返回true
            return true;
        }

        public static bool IsFileInUse(string fileName)
        {
            bool inUse = true;

            FileStream fs = null;
            try
            {

                fs = new FileStream(fileName, FileMode.Open, FileAccess.Read,

                FileShare.None);

                inUse = false;
            }
            catch
            {

            }
            finally
            {
                if (fs != null)

                    fs.Close();
            }
            return inUse;//true表示正在使用,false沒有使用
        }
    }
}