在YII中如何新添加一个component

Step1:

Make a folder named "components" in your project root folder.

step2:

write your custom component inside components folder eg:MyComponent.php

namespace app\components;
  
use Yii;
use yii\base\Component;
use yii\base\InvalidConfigException;
 
class MyComponent extends Component
{
 public function welcome()
 {
  echo "Hello..Welcome to MyComponent";
 }
 
}

Step3:

Add your component inside the config/web.php file

'components' => [
 
         'mycomponent' => [
 
            'class' => 'app\components\MyComponent',
 
                ],
           ]

Step4:

You are done!. Now you can use your component method "welcome" inside any of your app controller actions. eg:controllers/TestController.php

namespace app\controllers;
use Yii;
 
class TestController extends \yii\web\Controller
{
    public function actionWelcome()
    {
       Yii::$app->mycomponent->welcome();
    }
 
}