What is difference between a action with HTTPPOST or without it

    public ActionResult Index()
{
    return view();
    }

    [HTTPPOST]
    public ActionResult Index(){
    return vi开发者_Python百科ew();
    }

what is the difference between both in ASP.NET MVC

If you don't define any attribute above the method then Action accepts all kind requests (GET, POST etc.)

If you define [HttpPost] then only Post is accepted. In some cases it is very important to accept only certain kind of requests. W3.org has a good checklist when to use Get & Post.

Use GET if:

• The interaction is more like a question (i.e., it is a safe operation such as a query, read operation, or lookup).

Use POST if:

• The interaction is more like an order, or
• The interaction changes the state of the resource in a way that the user would perceive (e.g., a subscription to a service),
• or The user be held accountable for the results of the interaction.

Btw. In your example there is a problem with method signatures. Method signatures must be different even if you put attributes above them.