How to solve problem “The type 'System.Web.Mvc.ModelClientValidationRule' exists in both” when try open MVC3 project after installed MVC4

Simplest way:
Open project references list, and remove System.Web.WebPages.from references

http://stackoverflow.com/questions/7510484/modelclientvalidationrule-conflict

How to login into ASP.NET webforms site by HttpWebRequest

http://odetocode.com/articles/162.aspx

private void Button5_Click(object sender, System.EventArgs e)
{
// first, request the login form to get the viewstate value
HttpWebRequest webRequest = WebRequest.Create(LOGIN_URL) as HttpWebRequest;
StreamReader responseReader = new StreamReader(
webRequest.GetResponse().GetResponseStream()
);
string responseData = responseReader.ReadToEnd();
responseReader.Close();

// extract the viewstate value and build out POST data
string viewState = ExtractViewState(responseData);
string postData =
String.Format(
"__VIEWSTATE={0}&UsernameTextBox={1}&PasswordTextBox={2}&LoginButton=Login",
viewState, USERNAME, PASSWORD
);

// have a cookie container ready to receive the forms auth cookie
CookieContainer cookies = new CookieContainer();

// now post to the login form
webRequest = WebRequest.Create(LOGIN_URL) as HttpWebRequest;
webRequest.Method = "POST";
webRequest.ContentType = "application/x-www-form-urlencoded";
webRequest.CookieContainer = cookies;

// write the form values into the request message
StreamWriter requestWriter = new StreamWriter(webRequest.GetRequestStream());
requestWriter.Write(postData);
requestWriter.Close();

// we don't need the contents of the response, just the cookie it issues
webRequest.GetResponse().Close();

// now we can send out cookie along with a request for the protected page
webRequest = WebRequest.Create(SECRET_PAGE_URL) as HttpWebRequest;
webRequest.CookieContainer = cookies;
responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream());

// and read the response
responseData = responseReader.ReadToEnd();
responseReader.Close();

Response.Write(responseData);
}

How to add static html in ASP.NET MVC site?

Need to change routing setting in Global.asax.cs file like following:

        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.html/{*pathInfo}");
        }

How to change URL without reloading current page by Javascript

window.history.pushState('page2', 'Title', '/page2');

What is the difference between Html button and input type=button?

Almost same, but button with more rendering abilities.


Buttons created with the BUTTON element function just like buttons created with the INPUT element, but they offer richer rendering possibilities: the BUTTON element may have content. For example, a BUTTON element that contains an image functions like and may resemble an INPUT element whose type is set to “image”, but the BUTTON element type allows content.
The Button Element - W3C

References:
http://stackoverflow.com/questions/469059/button-vs-input-type-button-which-to-use
http://web.archive.org/web/20110721191046/http://particletree.com/features/rediscovering-the-button-element/