[c#] MVC which submit button has been pressed

I have two buttons on my MVC form:

<input name="submit" type="submit" id="submit" value="Save" />
<input name="process" type="submit" id="process" value="Process" />

From my Controller action how do I know which one have been pressed?

<input name="submit" type="submit" id="submit" value="Save" />
<input name="process" type="submit" id="process" value="Process" />

And in your controller action:

public ActionResult SomeAction(string submit)
{
    if (!string.IsNullOrEmpty(submit))
    {
        // Save was pressed
    }
    else
    {
        // Process was pressed
    }
}

you can identify your button from there name tag like below, You need to check like this in you controller

if (Request.Form["submit"] != null)
{
//Write your code here
}
else if (Request.Form["process"] != null)
{
//Write your code here
}

Here's a really nice and simple way of doing it with really easy to follow instructions using a custom MultiButtonAttribute:

http://blog.maartenballiauw.be/post/2009/11/26/Supporting-multiple-submit-buttons-on-an-ASPNET-MVC-view.aspx

To summarise, make your submit buttons like this:

<input type="submit" value="Cancel" name="action" />
<input type="submit" value="Create" name="action" /> 

Your actions like this:

[HttpPost]
[MultiButton(MatchFormKey="action", MatchFormValue="Cancel")]
public ActionResult Cancel()
{
    return Content("Cancel clicked");
}

[HttpPost]
[MultiButton(MatchFormKey = "action", MatchFormValue = "Create")]
public ActionResult Create(Person person)
{
    return Content("Create clicked");
} 

And create this class:

[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public class MultiButtonAttribute : ActionNameSelectorAttribute
{
    public string MatchFormKey { get; set; }
    public string MatchFormValue { get; set; }

    public override bool IsValidName(ControllerContext controllerContext, string actionName, MethodInfo methodInfo)
    {
        return controllerContext.HttpContext.Request[MatchFormKey] != null &&
            controllerContext.HttpContext.Request[MatchFormKey] == MatchFormValue;
    }
}

This post is not going to answer to Coppermill, because he have been answered long time ago. My post will be helpful for who will seeking for solution like this. First of all , I have to say " WDuffy's solution is totally correct" and it works fine, but my solution (not actually mine) will be used in other elements and it makes the presentation layer more independent from controller (because your controller depend on "value" which is used for showing label of the button, this feature is important for other languages.).

Here is my solution, give them different names:

<input type="submit" name="buttonSave" value="Save"/>
<input type="submit" name="buttonProcess" value="Process"/>
<input type="submit" name="buttonCancel" value="Cancel"/>

And you must specify the names of buttons as arguments in the action like below:

public ActionResult Register(string buttonSave, string buttonProcess, string buttonCancel)
{
    if (buttonSave!= null)
    {
        //save is pressed
    }
    if (buttonProcess!= null)
    {
        //Process is pressed
    }
    if (buttonCancel!= null)
    {
        //Cancel is pressed
    }
}

when user submits the page using one of the buttons, only one of the arguments will have value. I guess this will be helpful for others.

Update

This answer is quite old and I actually reconsider my opinion . maybe above solution is good for situation which passing parameter to model's properties. don't bother yourselves and take best solution for your project.

this is a better answer, so we can have both text and value for a button:

http://weblogs.asp.net/dfindley/archive/2009/05/31/asp-net-mvc-multiple-buttons-in-the-same-form.aspx

</p>
<button name="button" value="register">Register</button>
<button name="button" value="cancel">Cancel</button>
</p>

and the controller:

public ActionResult Register(string button, string userName, string email, string password, string confirmPassword)
{
if (button == "cancel")
    return RedirectToAction("Index", "Home");
...

in short its a SUBMIT button but you choose the name using the name attribute, its even more powerful because your not obligated to the name submit or button in the controller method parameters, you can call it as you like...

To make it easier I will say you can change your buttons to the following:

<input name="btnSubmit" type="submit" value="Save" />
<input name="btnProcess" type="submit" value="Process" />

Your controller:

public ActionResult Create(string btnSubmit, string btnProcess)
{
    if(btnSubmit != null)
       // do something for the Button btnSubmit
    else 
       // do something for the Button btnProcess
}

// Buttons
<input name="submit" type="submit" id="submit" value="Save" />
<input name="process" type="submit" id="process" value="Process" />

// Controller
[HttpPost]
public ActionResult index(FormCollection collection)
{
    string submitType = "unknown";

    if(collection["submit"] != null)
    {
        submitType = "submit";
    }
    else if (collection["process"] != null)
    {
        submitType = "process";
    }

} // End of the index method

In Core 2.2 Razor pages this syntax works:

    <button type="submit" name="Submit">Save</button>
    <button type="submit" name="Cancel">Cancel</button>
public async Task<IActionResult> OnPostAsync()
{
    if (!ModelState.IsValid)
        return Page();
    var sub = Request.Form["Submit"];
    var can = Request.Form["Cancel"];
    if (sub.Count > 0)
       {
       .......

Can you not find out using Request.Form Collection? If process is clicked the request.form["process"] will not be empty

Give the name to both of the buttons and Get the check the value from form.

<div>
   <input name="submitButton" type="submit" value="Register" />
</div>

<div>
   <input name="cancelButton" type="submit" value="Cancel" />
</div>

On controller side :

public ActionResult Save(FormCollection form)
{
 if (this.httpContext.Request.Form["cancelButton"] !=null)
 {
   // return to the action;
 }

else if(this.httpContext.Request.Form["submitButton"] !=null)
 {
   // save the oprtation and retrun to the action;
 }
}