yii2 上传图片的示例代码

.onedialog{position:absolute; left: 300px; top: 500px; z-index: 10; width: 700px; height: 400px;border-radius:5px;box-shadow:5px 2px 6px #000; border: 2px solid #666}
.one { width: 100%; height: 100% }

$(function(){
 $(\'#product-picurl\').click(function(){
 $(\'#oneupload\').remove();
 $(\'<div>\').appendTo($(\'body\')).attr({\"class\":\"onedialog\",\'id\':\"oneupload\"});
 $(\'< >\').appendTo($(\'#oneupload\')).attr({\"src\":\"?r=upload\",\"class\":\"one \"})
 });
  var v=$(\'#product-picurl\').val();
 if(v){
 $(\'<img>\').attr({\"src\":v,\"style\":\"height:50px\"}).insertAfter($(\'#product-picurl\'));
 }
});

class AppAsset extends AssetBundle
{
  public $ Path = \'@webroot\';
  public $ Url = \'@web\';
  public $css = [
    \'css/site.css\',
    \'css/main.css\',
  ];
  public $js = [
    \'assets/main.js\'
  ];
  public $depends = [
    \'yii\\web\\YiiAsset\',
    \'yii\\bootstrap\\BootstrapAsset\',
  ];
}

<?PHP
namespace frontend\\controllers;

use Yii;
use yii\\web\\Controller;
use app\\models\\UploadForm;
use yii\\web\\UploadedFile;

class UploadController extends Controller
{
  public function actionIndex()
  {
    $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-> Name . \'.\' . $model->file->extension);      
        $fileName=\'uploads/\' . date(\"YmdHis\") . \'.\' . $model->file->extension;
        $model->file->saveAs($fileName);
      }
      echo \"<  src=\'assets/upload.js\'></ >;\";
      echo \"< >\";
      echo \"var oneinput=parent.document.getElementById(\'product-picurl\');\";
      echo \"parent.document.getElementById(\'product-picurl\').value=\'\".$fileName.\"\';\";
      echo \"var oneupload = parent.document.getElementById(\'oneupload\');\";
      echo \"var img = document.createElement(\'img\');\";
      echo \"img.setAttribute(\'style\', \'height:50px\');\";
      echo \"img.src =\'\".$fileName.\"\';\";
      echo \"insertAfter(img,oneinput);\";
      echo \"oneupload.parentNode.removeChild(oneupload)\";
      echo \"</ >\";
    }

    return $this->render(\'upload\', [\'model\' => $model]);
  }
}
?>

<?PHP
namespace app\\models;

use yii\\ \\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\'],
    ];
  }
}
?>

<?php
use yii\\widgets\\ActiveForm;
?>

<?php $form = ActiveForm::begin([\'options\' => [\'enctype\' => \'multipart/form-data\']]) ?>

<?= $form->field($model, \'file\')->fileInput() ?>

<button>Submit</button>

<?php ActiveForm::end() ?>