【求助】c#如何用WebRequest下载一张网上的图片[顶者有分]

Question

HttpWebRequest req = (HttpWebRequest)WebRequest.Create(strURL);给个思路。。谢谢。

Answer 1

void DownLoadToFile(string Url, string Path)
{
    WebRequest HWR = WebRequest.Create(Url);
    WebResponse HWRr = HWR.GetResponse();    Stream SR = HWRr.GetResponseStream();
    FileStream S = File.Open(Path, FileMode.Create);
    byte[] by = new byte[1024];
    int o=1;
    while (o > 0)
    {
        o = SR.Read(by, 0, 1024);
        S.Write(by, 0, o);
    }
    S.Close();
    SR.Close();
    S.Dispose();
    SR.Dispose();
    HWR = null;
    HWRr = null;
}

Answer 2

这是我做验证码的时候用来读取图片的，具体是从哪参考来的记不得了。            MemoryStream stream = new MemoryStream(downloadData(tb_url.Text));
            Image img= Image.FromStream(stream);
       private byte[] downloadData(string url)
        {
            byte[] downloadedData = new byte[0];
            try
            {
                //Optional
                this.lb_status.Text = "Connecting...";
                Application.DoEvents();                //Get a data stream from the url
                WebRequest req = WebRequest.Create(url);
                WebResponse response = req.GetResponse();
                Stream stream = response.GetResponseStream();                //Download in chuncks
                byte[] buffer = new byte[1024];                //Get Total Size
                int dataLength = (int)response.ContentLength;                //With the total data we can set up our progress indicators                this.lb_status.Text = "Downloading...";
                Application.DoEvents();                //Download to memory
                //Note: adjust the streams here to download directly to the hard drive
                MemoryStream memStream = new MemoryStream();
                while (true)
                {
                    //Try to read the data
                    int bytesRead = stream.Read(buffer, 0, buffer.Length);                    if (bytesRead == 0)
                    {
                        Application.DoEvents();
                        break;
                    }
                    else
                    {
                        //Write the downloaded data
                        memStream.Write(buffer, 0, bytesRead);
                    }
                }                //Convert the downloaded stream to a byte array
                downloadedData = memStream.ToArray();                //Clean up
                stream.Close();
                memStream.Close();
            }
            catch (Exception)
            {
                //May not be connected to the internet
                //Or the URL might not exist
                MessageBox.Show("There was an error accessing the URL.");
            }
            this.lb_status.Text = "Download Data through HTTP";
            return downloadedData;
        }

Answer 3

public static void DownloadOneFileByURL(string fileName, string url, string localPath, int timeout)
       {
           System.Net.HttpWebRequest request = null;
           System.Net.HttpWebResponse response = null;
           request = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(url + fileName);
           request.Timeout = timeout;
           response = (System.Net.HttpWebResponse)request.GetResponse();
            Stream s = response.GetResponseStream();
            BinaryReader br = new BinaryReader(s);
            int len= Int32.Parse(response.ContentLength.ToString());
            byte[] byteArr = new byte[len];
            s.Read(byteArr, 0, len);
            if (File.Exists(localPath + fileName)) { File.Delete(localPath + fileName); }
           if (Directory.Exists(localPath) == false) { Directory.CreateDirectory(localPath); }
            FileStream fs = File.Create(localPath + fileName);
            fs.Write(byteArr, 0, len);
            fs.Close();
            br.Close();
        }
或用webclient

Answer 4

找到网页里的img src=之类的东西(用正则),然后在网址后面加上图片的路径,直接用WebClient下载之顶楼下的继续顶,有分

Answer 5

四行代码就可以：string strURL = "http://avatar.profile.csdn.net/4/1/A/2_yingkk.jpg";
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(strURL);
System.Drawing.Image img = System.Drawing.Image.FromStream(req.GetResponse().GetResponseStream());
img.Save("c:\\1.jpg");