Yii2 UploadedFile上传文件

通过

UploadFile::getInstance($model, $attribute);

UploadFile::getInstances($model, $attribute);

UploadFile::getInstanceByName($name);

UploadFile::getInstancesByName($name);

把表单上传的文件赋值到  UploadedFile中的  private static $_files  中

 /**
      * Returns an uploaded file for the given model attribute.
      * The file should be uploaded using [[\yii\widgets\ActiveField::fileInput()]].
      * @param \yii\base\Model $model the data model
      * @param string $attribute the attribute name. The attribute name may contain array indexes.
      * For example, '[1]file' for tabular file uploading; and 'file[1]' for an element in a file array.
      * @return UploadedFile the instance of the uploaded file.
      * Null is returned if no file is uploaded for the specified model attribute.
      * @see getInstanceByName()
      */
     public static function getInstance($model, $attribute)
     {
         $name = Html::getInputName($model, $attribute);
         return static::getInstanceByName($name);
     }

     /**
      * Returns all uploaded files for the given model attribute.
      * @param \yii\base\Model $model the data model
      * @param string $attribute the attribute name. The attribute name may contain array indexes
      * for tabular file uploading, e.g. '[1]file'.
      * @return UploadedFile[] array of UploadedFile objects.
      * Empty array is returned if no available file was found for the given attribute.
      */
     public static function getInstances($model, $attribute)
     {
         $name = Html::getInputName($model, $attribute);
         return static::getInstancesByName($name);
     }

     /**
      * Returns an uploaded file according to the given file input name.
      * The name can be a plain string or a string like an array element (e.g. 'Post[imageFile]', or 'Post[0][imageFile]').
      * @param string $name the name of the file input field.
      * @return UploadedFile the instance of the uploaded file.
      * Null is returned if no file is uploaded for the specified name.
      */
     public static function getInstanceByName($name)
     {
         $files = self::loadFiles();
         return isset($files[$name]) ? $files[$name] : null;
     }

     /**
      * Returns an array of uploaded files corresponding to the specified file input name.
      * This is mainly used when multiple files were uploaded and saved as 'files[0]', 'files[1]',
      * 'files[n]'..., and you can retrieve them all by passing 'files' as the name.
      * @param string $name the name of the array of files
      * @return UploadedFile[] the array of UploadedFile objects. Empty array is returned
      * if no adequate upload was found. Please note that this array will contain
      * all files from all sub-arrays regardless how deeply nested they are.
      */
     public static function getInstancesByName($name)
     {
         $files = self::loadFiles();
         if (isset($files[$name])) {
             return [$files[$name]];
         }
         $results = [];
         foreach ($files as $key => $file) {
             if (strpos($key, "{$name}[") === 0) {
                 $results[] = $file;
             }
         }
         return $results;
     }

loadFiles()方法，把$_FILES中的键值作为参数传递到loadFilesRecursive（$key, $names, $tempNames, $types, $sizes, $errors） 中

 /**
      * Creates UploadedFile instances from $_FILE.
      * @return array the UploadedFile instances
      */
     private static function loadFiles()
     {
         if (self::$_files === null) {
             self::$_files = [];
             if (isset($_FILES) && is_array($_FILES)) {
                 foreach ($_FILES as $class => $info) {
                     self::loadFilesRecursive($class, $info['name'], $info['tmp_name'], $info['type'], $info['size'], $info['error']);
                 }
             }
         }
         return self::$_files;
     }

loadFilesRecursive方法，通过递归把$_FILES中的内容保存到  self::$_files 中

 /**
      * Creates UploadedFile instances from $_FILE recursively.
      * @param string $key key for identifying uploaded file: class name and sub-array indexes
      * @param mixed $names file names provided by PHP
      * @param mixed $tempNames temporary file names provided by PHP
      * @param mixed $types file types provided by PHP
      * @param mixed $sizes file sizes provided by PHP
      * @param mixed $errors uploading issues provided by PHP
      */
     private static function loadFilesRecursive($key, $names, $tempNames, $types, $sizes, $errors)
     {
         if (is_array($names)) {
             foreach ($names as $i => $name) {
                 self::loadFilesRecursive($key . '[' . $i . ']', $name, $tempNames[$i], $types[$i], $sizes[$i], $errors[$i]);
             }
         } elseif ($errors !== UPLOAD_ERR_NO_FILE) {
             self::$_files[$key] = new static([
                 'name' => $names,
                 'tempName' => $tempNames,
                 'type' => $types,
                 'size' => $sizes,
                 'error' => $errors,
             ]);
         }
     }

实例:

html

 <form class="form-horizontal form-margin50" action="<?= \yii\helpers\Url::toRoute('upload-face') ?>"
                   method="post" enctype="multipart/form-data" id="form1">
                 <input type="hidden" name="_csrf" value="<?= Yii::$app->request->getCsrfToken() ?>">
                 <input type="file" name="head_pic" id="doc" style="display: none" onchange="setImagePreview()"/>
 </form>

php代码,打印的

  public static function uploadImage($userId = '', $tem = '')
     {
         $returnPath = '';
         $path = 'uploads/headpic/' . $userId;
         if (!file_exists($path)) {
             mkdir($path, 0777);
             chmod($path, 0777);
         }

         $patch = $path . '/' . date("YmdHis") . '_';
         $tmp = UploadedFile::getInstanceByName('head_pic');
         if ($tmp) {
             $patch = $path . '/' . date("YmdHis") . '_';
             $tmp->saveAs($patch . '1.jpg');
             $returnPath .= $patch;
         }

         return $returnPath;
     }

$tmp = UploadedFile::getInstanceByName('head_pic');
打印dump($tmp,$_FILES,$tmp->getExtension());

对应的 UploadedFile

 class UploadedFile extends Object
 {
     /**
      * @var string the original name of the file being uploaded
      */
     // "Chrysanthemum.jpg"
     public $name;
     /**
      * @var string the path of the uploaded file on the server.
      * Note, this is a temporary file which will be automatically deleted by PHP
      * after the current request is processed.
      */
     //  "C:\Windows\Temp\php8CEF.tmp"
     public $tempName;
     /**
      * @var string the MIME-type of the uploaded file (such as "image/gif").
      * Since this MIME type is not checked on the server-side, do not take this value for granted.
      * Instead, use [[\yii\helpers\FileHelper::getMimeType()]] to determine the exact MIME type.
      */
     //  "image/jpeg"
     public $type;
     /**
      * @var integer the actual size of the uploaded file in bytes
      */
     //
     public $size;
     /**
      * @var integer an error code describing the status of this file uploading.
      * @see http://www.php.net/manual/en/features.file-upload.errors.php
      */
     //
     public $error;

     private static $_files;

     /**
      * String output.
      * This is PHP magic method that returns string representation of an object.
      * The implementation here returns the uploaded file's name.
      * @return string the string representation of the object
      */
     public function __toString()
     {
         return $this->name;
     }

     /**
      * Returns an uploaded file for the given model attribute.
      * The file should be uploaded using [[\yii\widgets\ActiveField::fileInput()]].
      * @param \yii\base\Model $model the data model
      * @param string $attribute the attribute name. The attribute name may contain array indexes.
      * For example, '[1]file' for tabular file uploading; and 'file[1]' for an element in a file array.
      * @return UploadedFile the instance of the uploaded file.
      * Null is returned if no file is uploaded for the specified model attribute.
      * @see getInstanceByName()
      */
     public static function getInstance($model, $attribute)
     {
         $name = Html::getInputName($model, $attribute);
         return static::getInstanceByName($name);
     }

     /**
      * Returns all uploaded files for the given model attribute.
      * @param \yii\base\Model $model the data model
      * @param string $attribute the attribute name. The attribute name may contain array indexes
      * for tabular file uploading, e.g. '[1]file'.
      * @return UploadedFile[] array of UploadedFile objects.
      * Empty array is returned if no available file was found for the given attribute.
      */
     public static function getInstances($model, $attribute)
     {
         $name = Html::getInputName($model, $attribute);
         return static::getInstancesByName($name);
     }

     /**
      * Returns an uploaded file according to the given file input name.
      * The name can be a plain string or a string like an array element (e.g. 'Post[imageFile]', or 'Post[0][imageFile]').
      * @param string $name the name of the file input field.
      * @return null|UploadedFile the instance of the uploaded file.
      * Null is returned if no file is uploaded for the specified name.
      */
     public static function getInstanceByName($name)
     {
         $files = self::loadFiles();
         return isset($files[$name]) ? new static($files[$name]) : null;
     }

     /**
      * Returns an array of uploaded files corresponding to the specified file input name.
      * This is mainly used when multiple files were uploaded and saved as 'files[0]', 'files[1]',
      * 'files[n]'..., and you can retrieve them all by passing 'files' as the name.
      * @param string $name the name of the array of files
      * @return UploadedFile[] the array of UploadedFile objects. Empty array is returned
      * if no adequate upload was found. Please note that this array will contain
      * all files from all sub-arrays regardless how deeply nested they are.
      */
     public static function getInstancesByName($name)
     {
         $files = self::loadFiles();
         if (isset($files[$name])) {
             return [new static($files[$name])];
         }
         $results = [];
         foreach ($files as $key => $file) {
             if (strpos($key, "{$name}[") === 0) {
                 $results[] = new static($file);
             }
         }
         return $results;
     }

     /**
      * Cleans up the loaded UploadedFile instances.
      * This method is mainly used by test scripts to set up a fixture.
      */
     //清空self::$_files
     public static function reset()
     {
         self::$_files = null;
     }

     /**
      * Saves the uploaded file.
      * Note that this method uses php's move_uploaded_file() method. If the target file `$file`
      * already exists, it will be overwritten.
      * @param string $file the file path used to save the uploaded file
      * @param boolean $deleteTempFile whether to delete the temporary file after saving.
      * If true, you will not be able to save the uploaded file again in the current request.
      * @return boolean true whether the file is saved successfully
      * @see error
      */
     //通过php的move_uploaded_file() 方法保存临时文件为目标文件
     public function saveAs($file, $deleteTempFile = true)
     {
         //$this->error == UPLOAD_ERR_OK UPLOAD_ERR_OK  其值为 0，没有错误发生，文件上传成功。
         if ($this->error == UPLOAD_ERR_OK) {
             if ($deleteTempFile) {
                 //将上传的文件移动到新位置
                 return move_uploaded_file($this->tempName, $file);
             } elseif (is_uploaded_file($this->tempName)) {//判断文件是否是通过 HTTP POST 上传的
                 return copy($this->tempName, $file);//copy — 拷贝文件
             }
         }
         return false;
     }

     /**
      * @return string original file base name
      */
     //获取上传文件原始名称 "name" => "Chrysanthemum.jpg"  "Chrysanthemum"
     public function getBaseName()
     {
         // https://github.com/yiisoft/yii2/issues/11012
         $pathInfo = pathinfo('_' . $this->name, PATHINFO_FILENAME);
         return mb_substr($pathInfo, 1, mb_strlen($pathInfo, '8bit'), '8bit');
     }

     /**
      * @return string file extension
      */
     //获取上传文件扩展名称  "name" => "Chrysanthemum.jpg"  "jpg"
     public function getExtension()
     {
         return strtolower(pathinfo($this->name, PATHINFO_EXTENSION));
     }

     /**
      * @return boolean whether there is an error with the uploaded file.
      * Check [[error]] for detailed error code information.
      */
     //上传文件是否出现错误
     public function getHasError()
     {
         return $this->error != UPLOAD_ERR_OK;
     }

     /**
      * Creates UploadedFile instances from $_FILE.
      * @return array the UploadedFile instances
      */
     private static function loadFiles()
     {
         if (self::$_files === null) {
             self::$_files = [];
             if (isset($_FILES) && is_array($_FILES)) {
                 foreach ($_FILES as $class => $info) {
                     self::loadFilesRecursive($class, $info['name'], $info['tmp_name'], $info['type'], $info['size'], $info['error']);
                 }
             }
         }
         return self::$_files;
     }

     /**
      * Creates UploadedFile instances from $_FILE recursively.
      * @param string $key key for identifying uploaded file: class name and sub-array indexes
      * @param mixed $names file names provided by PHP
      * @param mixed $tempNames temporary file names provided by PHP
      * @param mixed $types file types provided by PHP
      * @param mixed $sizes file sizes provided by PHP
      * @param mixed $errors uploading issues provided by PHP
      */
     private static function loadFilesRecursive($key, $names, $tempNames, $types, $sizes, $errors)
     {
         if (is_array($names)) {
             foreach ($names as $i => $name) {
                 self::loadFilesRecursive($key . '[' . $i . ']', $name, $tempNames[$i], $types[$i], $sizes[$i], $errors[$i]);
             }
         } elseif ((int)$errors !== UPLOAD_ERR_NO_FILE) {
             self::$_files[$key] = [
                 'name' => $names,
                 'tempName' => $tempNames,
                 'type' => $types,
                 'size' => $sizes,
                 'error' => $errors,
             ];
         }
     }
 }