yii2解决POST提交数据时因启用Csrf出现的400错误

Yii2 默认是启用CSRF令牌验证，解决办法有如下三种：

第一种：配置在main.php中：

'components' => [
        'request' => [
            // !!! insert a secret key in the following (if it is empty) - this is required by cookie validation
            'enableCookieValidation' => true,
            'cookieValidationKey' => 'cookvalid',
  ],

若要取消CSRF验证有两种方法

1. 在要取消的控制器中添加：

public $enableCsrfValidation = false;

2. 在配置中取消enableCookieValidation的验证

'components' => [
        'request' => [
            // !!! insert a secret key in the following (if it is empty) - this is required by cookie validation
            'enableCookieValidation' => false,
            'cookieValidationKey' => 'cookvalid',
],

第二种：是在form表单中加入隐藏域

<input name="_csrf" type="hidden" id="_csrf" value="<?= Yii::$app->request->csrfToken ?>">

第三种：在AJAX中加入_csrf字段

var csrfToken = $('meta[name="csrf-token"]').attr("content");
$.ajax({
  type: 'POST',
  url: url,
  data: {_csrf:csrfToken},
  success: success,
  dataType: dataType
});