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'],
    ];
  }
}

<"htmlcode">

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：


<"htmlcode">

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


Controller:


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) {
      $model->file = UploadedFile::getInstances($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。


参考https://github.com/yiisoft/yii2/blob/master/docs/guide/input-file-upload.md


以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。