C# 根据路径（URL）下载图片，保存对应路径

C# 根据路径（URL）下载图片，保存对应路径，方便进一步的访问

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebApplication
{
    public partial class PICTURE : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (Request.QueryString["url"] != null)
            {
                //upload/2020/03/202003081583644238196529.png
                string url = Request.QueryString["url"].ToString();
                string savePath = Server.MapPath("~/" + url);

                if (File.Exists(savePath))
                {
                    //存在
                    Response.Redirect("http://localhost:2064/upload/2020/03/202003081583644238196529.png");
                }
                else
                {
                    string fielpath = savePath.Substring(0, savePath.LastIndexOf('\\'));

                    string fileName = savePath.Substring(savePath.LastIndexOf("\\", savePath.Length - 1));
                    if (!System.IO.Directory.Exists(fielpath))
                    {
                        System.IO.Directory.CreateDirectory(fielpath);//不存在就创建文件夹
                    }

                    bool i = DownloadPicture("https://vtzw.com/zb_users/upload/2020/03/202003081583644238196529.png", fielpath + fileName, -1);

                    if (i)
                    {
                        Response.Redirect("http://localhost:2064/upload/2020/03/202003081583644238196529.png");
                    }
                }
            }
            
        }

        /// <summary>
        /// 下载图片
        /// </summary>
        /// <param name="picUrl">图片Http地址</param>
        /// <param name="savePath">保存路径</param>
        /// <param name="timeOut">Request最大请求时间，如果为-1则无限制</param>
        /// <returns></returns>
        public bool DownloadPicture(string picUrl, string savePath, int timeOut)
        {
            bool value = false;
            WebResponse response = null;
            Stream stream = null;
            try
            {
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(picUrl);
                if (timeOut != -1) request.Timeout = timeOut;
                response = request.GetResponse();
                stream = response.GetResponseStream();
                if (!response.ContentType.ToLower().StartsWith("text/"))
                    value = SaveBinaryFile(response, savePath);
            }
            finally
            {
                if (stream != null) stream.Close();
                if (response != null) response.Close();
            }
            return value;
        }
        private static bool SaveBinaryFile(WebResponse response, string savePath)
        {
            bool value = false;
            byte[] buffer = new byte[1024];
            Stream outStream = null;
            Stream inStream = null;
            try
            {
                if (File.Exists(savePath)) File.Delete(savePath);
                outStream = System.IO.File.Create(savePath);
                inStream = response.GetResponseStream();
                int l;
                do
                {
                    l = inStream.Read(buffer, 0, buffer.Length);
                    if (l > 0) outStream.Write(buffer, 0, l);
                } while (l > 0);
                value = true;
            }
            finally
            {
                if (outStream != null) outStream.Close();
                if (inStream != null) inStream.Close();
            }
            return value;
        }
 
    }



}