Not able to get post data from observer : M2

Question

i want to get form data from checkout page in 2nd step, so i have use event observer.

I have use this controller_action_predispatch_checkout event.

I want to get post data so i have try this link Get post data, in Checkout success observer but not able to get post data.

Can any one help me how can i get post data?

event.xml

<event name="controller_action_predispatch_checkout">
       <observer name="ptg_paymentevent_observer_checkoutpredispatchobserver" instance="Ptg\Paymentevent\Observer\Checkoutpredispatchobserver" />
   </event>

Checkoutpredispatchobserver.php

<?php
namespace Ptg\Paymentevent\Observer;

use Magento\Framework\Event\ObserverInterface; 
use Magento\Framework\Event\Observer as EventObserver; 

class Checkoutpredispatchobserver implements ObserverInterface 
{
    protected $_request;
    public function __construct(
        \Magento\Framework\App\RequestInterface $request
    )
    {
        $this->_request = $request;
    }

  public function execute(\Magento\Framework\Event\Observer $observer)
  {
     //$order= $observer->getData('order');
     //$order->doSomething(); product = $observer->getEvent()->getProduct();
      $reqeustParams = $this->_request->getParams(); 
            echo '<pre>';
            var_dump($reqeustParams);
            echo '</pre>';




     return $this;
        }

        }
  }
}

Answer 1

You need to try this code.

<?php namespace Vendor\Extension\Observer; 

use Magento\Framework\Event\ObserverInterface; 
use Magento\Framework\Event\Observer as EventObserver; 

class Yourclass implements ObserverInterface 
{ 
   protected $_request; 

   public function __construct( \Magento\Framework\App\RequestInterface $request) 
   { 
      $this->_request = $request; 
   } 

   public function execute(EventObserver $observer) 
   { 
        $reqeustParams = $this->_request->getParams(); 
        //check into $requestparams
   } 
}