Yii2的Alert组件（消息提示） [ 2.0 版本 ]

该组件提供五种类型提示，总的样式有四种，提示类型有：error，danger，success，info，warning；样式有：alert-danger，lert-success，alert-info，alert-warning ；

使用方法：在控制器中加入：

\Yii::$app->getSession()->setFlash('success', "头像设置成功！");

视图页面中引用：

use app\components\widgets\Alert;
<?= Alert::widget() ?>

其实在控制器中没多大作用，就是在类中添加，可以很好做到提示作用；

具体 Alert.php 代码 如下：

<?php      
namespace app\components\widgets;        
        
class Alert extends \yii\bootstrap\Widget
{
            
    public $alertTypes = [
        'error'   => 'alert-danger',
        'danger'  => 'alert-danger',
        'success' => 'alert-success',
        'info'    => 'alert-info',
        'warning' => 'alert-warning'
    ];
        
public $closeButton = [];
        
public function init()
{
    parent::init();
        
    $session = \Yii::$app->getSession();
    $flashes = $session->getAllFlashes();
    $appendCss = isset($this->options['class']) ? ' ' . $this->options['class'] : '';
        
    foreach ($flashes as $type => $data) {
    if (isset($this->alertTypes[$type])) {
        $data = (array) $data;
        foreach ($data as $message) {
        /* initialize css class for each alert box */
        $this->options['class'] = $this->alertTypes[$type] . $appendCss;
        
        /* assign unique id to each alert box */
        $this->options['id'] = $this->getId() . '-' . $type;
        
        echo \yii\bootstrap\Alert::widget([
            'body' => $message,
            'closeButton' => $this->closeButton,
            'options' => $this->options,
        ]);
        }
        
        $session->removeFlash($type);
        }
        }
    }
}