Magento2 not able to get & save customer custom attribute

Question

I am using Magento 2.1.5, and created custom attribute for customer and trying to get & set the values of custom attribute but didn't get custom attribute in customer collection and as well as set also.

add custom attribute:

 $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);
    $eavSetup->removeAttribute(\Magento\Customer\Model\Customer::ENTITY, 'sample_attribute');
    $eavSetup->addAttribute(
        \Magento\Customer\Model\Customer::ENTITY,
        'sample_attribute',
        [
            'type' => 'int',
            'label' => 'Sample Attribute',
            'input' => 'select',
            'source' => 'Magento\Eav\Model\Entity\Attribute\Source\Boolean',
            'required' => true,
            'default' => '0',
            'sort_order' => 100,
            'system' => false,
            'position' => 100
        ]
    );
    $sampleAttribute = $this->eavConfig->getAttribute(\Magento\Customer\Model\Customer::ENTITY, 'sample_attribute');
    $sampleAttribute->setData(
        'used_in_forms',
        ['adminhtml_customer_address', 'customer_address_edit', 'customer_register_address']
    );
    $sampleAttribute->save();

Get custom attribute value :

   $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
    $customerRepository = $objectManager->create('Magento\Customer\Model\Customer')->load('1');
    echo "<pre>"; print_r($customerRepository->getData());

Answer 1

You have to call below class in __consturct() function in your controller file and get and set value from customer.

  <?php
    public function __construct(
        \Magento\Framework\App\Action\Context $context,
        \Magento\Customer\Api\CustomerRepositoryInterface $customerRepository
    )
    {        
        $this->customerRepository = $customerRepository;
        parent::__construct($context);
    }

    public function getCustomerAttribute(){
        $customerId = 1;
        $customer = $this->customerRepository->getById($customerId);

        //get customer custom attribute value
        $customer->getCustomAttribute('sample_attribute');

        //set customer custom attribute value
        $sample_attribute = 2;
        $customer->setCustomAttribute('sample_attribute',$sample_attribute);
       try {                
            $customer = $this->customerRepository->save($customer);
        }catch (Exception $e) {
            return $e->getMessage();
        }
    }

Remove var/generation folder.clear cache.