yii中上传图片总结

Yii 提供了 CUploadedFile 来上传文件，比如图片，或者文档。 

官方关于这个类的介绍 :

CUploadedFile represents the information for an uploaded file. 
Call getInstance to retrieve the instance of an uploaded file, and then use saveAs to save it on the server. You may also query other information about the file, including name, tempName, type, size and error.

public properties

Property	Type	Description	Defined By
error	integer	Returns an error code describing the status of this file uploading.	CUploadedFile
extensionName	string	the file extension name for name.	CUploadedFile
hasError	boolean	whether there is an error with the uploaded file.	CUploadedFile
name	string	the original name of the file being uploaded	CUploadedFile
size	integer	the actual size of the uploaded file in bytes	CUploadedFile
tempName	string	the path of the uploaded file on the server.	CUploadedFile
type	string	the MIME-type of the uploaded file (such as "image/gif").	CUploadedFile

实现上传文件，要用到MVC三个层面。 

1、 模型层面 M ，把一个字段在rules方法里设置为 file 属性。

[php]  view plain copy print ?

1. array('url',  
2.                 'file',    //定义为file类型  
3.                 'allowEmpty'=>true,   
4.                 'types'=>'jpg,png,gif,doc,docx,pdf,xls,xlsx,zip,rar,ppt,pptx',   //上传文件的类型  
5.                 'maxSize'=>1024*1024*10,    //上传大小限制，注意不是php.ini中的上传文件大小  
6.                 'tooLarge'=>'文件大于10M，上传失败！请上传小于10M的文件！'  
7.             ),  

2、视图层View，这里需要用到CHtml::activeFileField 来生成选择文件的button，注意是上传文件，所以在该标单中enctype应该设置为： multupart/form-data 

[php]  view plain copy print ?

1. <?php $form=$this->beginWidget('CActiveForm', array(  
2. <span style="white-space:pre">  </span>'id'=>'link-form',  
3. <span style="white-space:pre">  </span>'enableAjaxValidation'=>false,  
4. <span style="white-space:pre">  </span>'htmlOptions' => array('enctype'=>'multipart/form-data'),  
5. )); ?>  

[php]  view plain copy print ?

1.   

[php]  view plain copy print ?

1. <div class="row">  
2.         <?php echo $form->labelEx($model,'url'); ?>  
3.         <?php echo CHtml::activeFileField($model,'url'); ?>  
4.         <?php echo $form->error($model,'url'); ?>  
5.     </div>  

3、控制层 C  

[php]  view plain copy print ?

1. $model=new Link;  
2.         if(isset($_POST['Link']))  
3.         {  
4.             $model->attributes=$_POST['Link'];  
5.             if(empty($_POST['Link']['name'])){  
6.                 $model->name = $model->url;  
7.             }  
8.             $file = CUploadedFile::getInstance($model,'url');   //获得一个CUploadedFile的实例  
9.             if(is_object($file)&&get_class($file) === 'CUploadedFile'){   // 判断实例化是否成功  
10.                 $model->url = './assets/upfile/file_'.time().'_'.rand(0,9999).'.'.$file->extensionName;   //定义文件保存的名称  
11.             }else{  
12.                 $model->url = './assets/upfile/noPic.jpg';   // 若果失败则应该是什么图片  
13.             }  
14.             if($model->save()){  
15.                 if(is_object($file)&&get_class($file) === 'CUploadedFile'){  
16.                     $file->saveAs($model->url);    // 上传图片  
17.                 }  
18.                 $this->redirect(array('view','id'=>$model->lid));  
19.             }         
20.         }