deactive-plugin.php

<?php
/**
 * Example code taken from: https://pento.net/2014/02/18/dont-let-your-plugin-be-activated-on-incompatible-sites/
 */

//  In this example, only allow activation on WordPress 3.7 or higherclass 
MyPlugin {
	function __construct() {
		add_action( 'admin_init', array( $this, 'check_version' ) );
		
		// Don't run anything else in the plugin, if we're on an incompatible WordPress version
		if ( ! self::compatible_version() ) {
			return;
		}
	}
	
	// The primary sanity check, automatically disable the plugin on activation if it doesn't// meet minimum requirements.static
	function activation_check() {
		if ( ! self::compatible_version() ) {
			deactivate_plugins( plugin_basename( __FILE__ ) );
			wp_die( __( 'My Plugin requires WordPress 3.7 or higher!', 'my-plugin' ) );
		}
	}
	
	// The backup sanity check, in case the plugin is activated in a weird way,
	// or the versions change after activation.
	function check_version() {
		if ( ! self::compatible_version() ) {
			if ( is_plugin_active( plugin_basename( __FILE__ ) ) ) {
				deactivate_plugins( plugin_basename( __FILE__ ) );
				add_action( 'admin_notices', array( $this, 'disabled_notice' ) );
				
				if ( isset( $_GET['activate'] ) ) {
					unset( $_GET['activate'] );
				}
			}
		}
	}
	
	function disabled_notice() {
		echo '<strong>' . esc_html__( 'My Plugin requires WordPress 3.7 or higher!', 'my-plugin' ) . '</strong>';
	}
	
	static function compatible_version() {
		if ( version_compare( $GLOBALS['wp_version'], '3.7', '<' ) ) {
			return false;
		}
		
		// Add sanity checks for other version requirements here
		
		return true;
	}
}

global $myplugin;
$myplugin = new MyPlugin();
register_activation_hook( __FILE__, array( 'MyPlugin', 'activation_check' ) );