C# HTML解析和设置默认下拉列表项

C# HTML解析和设置默认下拉列表项,c#,html,parsing,dropdownbox,C#,Html,Parsing,Dropdownbox,我的代码如下: NameValueCollection nvc = new NameValueCollection(); nvc.Add("id", "userfile"); // <- select the file nvc.Add("preview", "Upload"); // <- push the upload button on website ImportUtilities.HttpUploadFile("http://www.site.com/",

我的代码如下:

NameValueCollection nvc = new NameValueCollection();
nvc.Add("id", "userfile");       // <- select the file
nvc.Add("preview", "Upload");    // <- push the upload button on website
ImportUtilities.HttpUploadFile("http://www.site.com/", "image.png", "userfile", "image/png", nvc);
NameValueCollection nvc=新的NameValueCollection();

nvc.Add(“id”,“userfile”);//永远不要将代码作为图像发布。复制它并粘贴为文本对不起,我的坏。但是,您能帮我解决这个问题吗?当然,粘贴代码有什么问题?不是粘贴代码,将要将A项设置为默认项。。你能帮助我吗?