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 app/models;use yii/base/Model;use yii/web/UploadedFile;/** * 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

<?phpuse yii/widgets/ActiveForm;?><?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 app/controllers;use Yii;use yii/web/Controller;use app/models/UploadForm;use yii/web/UploadedFile;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：

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