C#获取IE窗口和简单操作

/// <summary>
/// 返回指定Url的IE窗口下的 IHTMLDocument2 对象。
/// </summary>
/// <returns>IHTMLDocument2</returns>
public static IHTMLDocument2 GetIHTMLDocument2ByUrl(string url)
{
    SHDocVw.ShellWindows shellWindows = new SHDocVw.ShellWindowsClass();
    foreach (SHDocVw.InternetExplorer ie in shellWindows)
    {
       string filename = System.IO.Path.GetFileNameWithoutExtension(ie.FullName).ToLower();
       if (filename.Equals("iexplore") && ie.LocationURL == url)
       {
           return ie.Document as IHTMLDocument2;
       }
    }
}

IHTMLDocument2 iHTMLDocument2 = GetIHTMLDocument2ByUrl("http://www.163.com");
IHTMLInputElement input = (IHTMLInputElement)iHTMLDocument2.all.item("Username", 0); // 获取指定名称的对象
input.value = "Xiao"; // 赋值

IHTMLDocument2 iHTMLDocument2 = GetIHTMLDocument2ByUrl("http://www.163.com");
HTMLDocumentClass obj = (HTMLDocumentClass)iHTMLDocument2;
IHTMLElement iHTMLElement = null;
IHTMLElementCollection c = obj.getElementsByTagName("input");
foreach (IHTMLElement e in c)
{
    if (e.outerHTML.IndexOf("登录") != -1)
    {
         iHTMLElement = e;
         break;
    }
}
if (iHTMLElement != null)
{
    iHTMLElement.click(); // 点击登录按钮
}