同一会话中的多个WebRequest

Question

我正在尝试编写一个将网页(及其图像)保存为html页面的功能.我正在使用HttpWebRequest来请求网页的内容.我的功能看起来像

void SaveUrl(string sourceURL, string savepath)
{
    HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(sourceURL);
    HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();
    StreamReader responseReader = new StreamReader(response.GetResponseStream());

    string sResponseHTML = responseReader.ReadToEnd();
    using (StreamWriter sw = new StreamWriter(savepath, false))
    {
        sw.Write(sResponseHTML);
    }

    string[] ImageUrl = GetImgLinks(sResponseHTML);
    foreach (string imagelink in ImageUrl)
    {
        HttpWebRequest imgRequest = (HttpWebRequest)WebRequest.Create(imagelink);
        HttpWebResponse imgresponse = (HttpWebResponse)imgRequest.GetResponse();
        //Code to save image
    }
}

我的问题是我想在同一个会话中创建所有webrequest并且不想为每个imgRequest创建一个新会话,因为我的网页上的许多图像都是动态生成的并且是临时存储的.因此,如果我在同一会话中发出请求,则只能获取这些图像.

Answer 1

会话通常使用cookie.如果您希望所有请求都属于同一会话,则需要在请求之间保留cookie.您可以通过创建CookieContainer并将其提供给每个HttpWebRequest对象来完成此操作.

这是您更新的代码以使用CookieContainer:

    void SaveUrl(string sourceURL, string savepath) {
        CookieContainer cookies = new CookieContainer();
        HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(sourceURL);
        webRequest.CookieContainer = cookies;

        HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();
        StreamReader responseReader = new StreamReader(response.GetResponseStream());

        string sResponseHTML = responseReader.ReadToEnd();
        using (StreamWriter sw = new StreamWriter(savepath, false)) {
            sw.Write(sResponseHTML);
        }

        string[] ImageUrl = GetImgLinks(sResponseHTML);
        foreach (string imagelink in ImageUrl) {
            HttpWebRequest imgRequest = (HttpWebRequest)WebRequest.Create(imagelink);
            imgRequest.CookieContainer = cookies;
            HttpWebResponse imgresponse = (HttpWebResponse)imgRequest.GetResponse();
            //Code to save image
        }
    }