Yii2使用表单上传文件的实例代码

yii2用表单上传文件经常用到的，该怎样上传呢？

1、单个文件上传

首先建立一个模型models/UploadForm.php,内容如下

  namespace appmodels;    use yiibaseModel;  use yiiwebUploadedFile;    /**   * UploadForm is the model behind the upload form.   */  class UploadForm extends Model  {    /**     * @var UploadedFile file attribute     */    public $file;      /**     * @return array the validation rules.     */    public function rules()    {      return [        [['file'], 'file'],      ];    }  }

再建立一个视图文件，内容如下

  <?php  use yiiwidgetsActiveForm;  ?>    <?php $form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data']]) ?>    <?= $form->field($model, 'file')->fileInput() ?>    <button>Submit</button>    <?php ActiveForm::end() ?>

最后建立控制器文件，内容如下

  namespace appcontrollers;    use Yii;  use yiiwebController;  use appmodelsUploadForm;  use yiiwebUploadedFile;    class SiteController extends Controller  {    public function actionUpload()    {      $model = new UploadForm();        if (Yii::$app->request->isPost) {        $model->file = UploadedFile::getInstance($model, 'file');          if ($model->file && $model->validate()) {                  $model->file->saveAs('uploads/' . $model->file->baseName . '.' . $model->file->extension);        }      }        return $this->render('upload', ['model' => $model]);    }  }

注意这里我们没有用model->load(…)，而是用了UploadedFile::getInstance(…)。区别是后者不会执行$model->validate()，所以需要手动的去执行$model->validate()来检验数据的合法性。如果检验通过了，上传的文件保存在uploads文件夹下，即web目录下的uploads里。

一些可选的配置选项

上传文件不能为空

  public function rules()  {    return [      [['file'], 'file', 'skipOnEmpty' => false],    ];  }

上传类型，不仅可以根据扩展名检验，还可以根据文件的内容进行检验

  public function rules()  {    return [      [['file'], 'file', 'extensions' => 'jpg, png', 'mimeTypes' => 'image/jpeg, image/png',],    ];  }

2、多文件上传

如果你想一次上传多个文件，只需调节几个参数就可以达到目的

Model：

  class UploadForm extends Model  {    /**     * @var UploadedFile|Null file attribute     */    public $file;      /**     * @return array the validation rules.     */    public function rules()    {      return [        [['file'], 'file', 'maxFiles' => 10], // <--- here!      ];    }  }

View：

  <?php  use yiiwidgetsActiveForm;    $form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data']]);  ?>    <?= $form->field($model, 'file[]')->fileInput(['multiple' => true]) ?>      <button>Submit</button>    <?php ActiveForm::end(); ?>

与单文件上传不同的是下面这句

  $form->field($model, 'file[]')->fileInput(['multiple' => true])

Controller:

  namespace appcontrollers;    use Yii;  use yiiwebController;  use appmodelsUploadForm;  use yiiwebUploadedFile;    class SiteController extends Controller  {    public function actionUpload()    {      $model = new UploadForm();        if (Yii::$app->request->isPost) {        $model->file = UploadedFile::getInstances($model, 'file');          if ($model->file && $model->validate()) {          foreach ($model->file as $file) {            $file->saveAs('uploads/' . $file->baseName . '.' . $file->extension);          }        }      }        return $this->render('upload', ['model' => $model]);    }  }

这样就可以实现多文件上传了。