Yii框架实现图片上传的方法详解

<?phpclass Upload extends CActiveRecord {  public $image;  public static function model($className = __CLASS__) {    return $className;  }  public function tableName() {    return '{{resource}}';  }  public function rules() {    return array(      array('image', 'file', 'types'=>'jpg, gif, png')    );  }}

<?phpclass UploadController extends Controller {  public function actionIndex() {    $model=new Upload;    if(isset($_POST['Upload'])) {      $model->image=CUploadedFile::getInstance($model,'image');      $ext = $model->image->getExtensionName();      $fileName = uniqid() . '.' . $ext;      $model->image->saveAs('assets/' . $fileName);    }    $this->renderPartial('index', array('model'=>$model));  }}

<meta charset="utf-8"><?php echo CHtml::form(SITE_URL . 'admin/upload/index','post',array('enctype'=>'multipart/form-data')); ?><?php echo CHtml::activeFileField($model, 'image'); ?><?php echo CHtml::submitButton('提交');?><?php echo CHtml::endForm(); ?>

<?phpclass Image extends CController {  /**   +----------------------------------------------------------   * 取得图像信息   *   +----------------------------------------------------------   * @static   * @access public   +----------------------------------------------------------   * @param string $image 图像文件名   +----------------------------------------------------------   * @return mixed   +----------------------------------------------------------   */  static function getImageInfo($img) {    $imageInfo = getimagesize($img);    if ($imageInfo !== false) {      $imageType = strtolower(substr(image_type_to_extension($imageInfo[2]), 1));      $imageSize = filesize($img);      $info = array(        "width" => $imageInfo[0],        "height" => $imageInfo[1],        "type" => $imageType,        "size" => $imageSize,        "mime" => $imageInfo['mime']      );      return $info;    } else {      return false;    }  }  /**   +----------------------------------------------------------   * 生成缩略图   +----------------------------------------------------------   * @static   * @access public   +----------------------------------------------------------   * @param string $image 原图   * @param string $type 图像格式   * @param string $thumbname 缩略图文件名   * @param string $maxWidth 宽度   * @param string $maxHeight 高度   * @param string $position 缩略图保存目录   * @param boolean $interlace 启用隔行扫描   +----------------------------------------------------------   * @return void   +----------------------------------------------------------   */  static function thumb($image, $thumbname, $type='', $maxWidth=200, $maxHeight=50, $interlace=true) {    // 获取原图信息    $info = Image::getImageInfo($image);    if ($info !== false) {      $srcWidth = $info['width'];      $srcHeight = $info['height'];      $type = empty($type) ? $info['type'] : $type;      $type = strtolower($type);      $interlace = $interlace ? 1 : 0;      unset($info);      $scale = min($maxWidth / $srcWidth, $maxHeight / $srcHeight); // 计算缩放比例      if ($scale >= 1) {        // 超过原图大小不再缩略        $width = $srcWidth;        $height = $srcHeight;      } else {        // 缩略图尺寸        $width = (int) ($srcWidth * $scale);        $height = (int) ($srcHeight * $scale);      }      // 载入原图      $createFun = 'ImageCreateFrom' . ($type == 'jpg' ? 'jpeg' : $type);      if(!function_exists($createFun)) {        return false;      }      $srcImg = $createFun($image);      //创建缩略图      if ($type != 'gif' && function_exists('imagecreatetruecolor'))        $thumbImg = imagecreatetruecolor($width, $height);      else        $thumbImg = imagecreate($width, $height);       //png和gif的透明处理 by luofei614      if('png'==$type){        imagealphablending($thumbImg, false);//取消默认的混色模式（为解决阴影为绿色的问题）        imagesavealpha($thumbImg,true);//设定保存完整的 alpha 通道信息（为解决阴影为绿色的问题）      }elseif('gif'==$type){        $trnprt_indx = imagecolortransparent($srcImg);         if ($trnprt_indx >= 0) {            //its transparent            $trnprt_color = imagecolorsforindex($srcImg , $trnprt_indx);            $trnprt_indx = imagecolorallocate($thumbImg, $trnprt_color['red'], $trnprt_color['green'], $trnprt_color['blue']);            imagefill($thumbImg, 0, 0, $trnprt_indx);            imagecolortransparent($thumbImg, $trnprt_indx);       }      }      // 复制图片      if (function_exists("ImageCopyResampled"))        imagecopyresampled($thumbImg, $srcImg, 0, 0, 0, 0, $width, $height, $srcWidth, $srcHeight);      else        imagecopyresized($thumbImg, $srcImg, 0, 0, 0, 0, $width, $height, $srcWidth, $srcHeight);      // 对jpeg图形设置隔行扫描      if ('jpg' == $type || 'jpeg' == $type)        imageinterlace($thumbImg, $interlace);      // 生成图片      $imageFun = 'image' . ($type == 'jpg' ? 'jpeg' : $type);      $imageFun($thumbImg, $thumbname);      imagedestroy($thumbImg);      imagedestroy($srcImg);      return $thumbname;    }    return false;  }}?>

// autoloading model and component classes  'import'=>array(    'application.models.*',    'application.components.*',    'application.extensions.*',  #加上此行，意思为自动载入  ),

public function actionIndex() {    $model=new Upload;    if(isset($_POST['Upload'])) {      $model->image=CUploadedFile::getInstance($model,'image');      $ext = $model->image->getExtensionName();      $fileName = uniqid() . '.' . $ext;      $model->image->saveAs('assets/' . $fileName);      // 生成缩略图      Image::thumb('assets/' . $fileName, 'assets/' . uniqid() . '.' . $ext);    }    $this->renderPartial('index', array('model'=>$model));}