CI多文件上传

CI官网手册上面写道，文件上传：

function getUploadName($field="prize_file")
{
    $config['upload_path']   = 'uploads/prizepath/';
    $config['allowed_types'] = 'gif|jpg|png|swf|bmp|txt';
    $config['file_name']     = date('Ymdhis').rand(100, 999);
    $config['max_size']      = '1024';
    $config['max_width']     = '0';
    $config['max_height']    = '0';

    $this->load->library('upload', $config);

    if(!dir_create($config['upload_path']))
    {
        exit('上传目录出错');
    }

    if( ! $this->upload->do_upload($field))
    {
        $data = array('error' => $this->upload->display_errors());
    }
    else
    {
        $data = array('upload_data' => $this->upload->data());
    }

    return $data;
}

这是单文件上传，文件的格式是：

array (size=5)
  'name' => 

string

 '640-300-50k.jpg' (length=15)
  'type' => 

string

 'image/jpeg' (length=10)
  'tmp_name' => 

string

 'E:wamp	mpphp9A91.tmp' (length=23)
  'error' => 

int

 0
  'size' => 

int

 50953
如果要多文件上传呢：
文件的格式是：

array (size=5)
  'name' => 
    array (size=4)
      0 => 

string

 '640-300-50k.jpg' (length=15)
      1 => 

string

 '20160727051524365.jpg' (length=21)
      2 => 

string

 '' (length=0)
      3 => 

string

 '' (length=0)
  'type' => 
    array (size=4)
      0 => 

string

 'image/jpeg' (length=10)
      1 => 

string

 'image/jpeg' (length=10)
      2 => 

string

 '' (length=0)
      3 => 

string

 '' (length=0)
  'tmp_name' => 
    array (size=4)
      0 => 

string

 'E:wamp	mpphp79C9.tmp' (length=23)
      1 => 

string

 'E:wamp	mpphp79CA.tmp' (length=23)
      2 => 

string

 '' (length=0)
      3 => 

string

 '' (length=0)
  'error' => 
    array (size=4)
      0 => 

int

 0
      1 => 

int

 0
      2 => 

int

 4
      3 => 

int

 4
  'size' => 
    array (size=4)
      0 => 

int

 50953
      1 => 

int

 42920
      2 => 

int

 0
      3 => 

int

 0

这个时候最关键的思路就是：
把多文件上传，组装成单文件上传的格式，并且，每个文件的名字要不同，附上代码：

foreach($_FILES['prize_file']['error'] as $k=>$v){
    if($v!=4){
        $field="prize_file".$k;   ----------（这一步很关键）
        $_FILES[$field]=array("name"=>$_FILES["prize_file"]['name'][$k],"type"=>$_FILES['prize_file']['type'][$k],"tmp_name"=>$_FILES['prize_file']['tmp_name'][$k],"error"=>$_FILES['prize_file']['error'][$k],"size"=>$_FILES['prize_file']['size'][$k]);
        $data = $this->getUploadName($field); -------（这个时候，每个文件上传的名字就不同了）
        $upload_data[]=$data;

    }
}