该程序可以实现:
1.同时上传5张图片
2.同时生成两种尺寸的缩略图
3.保存到mysql

controllers：upload.php文件：

复制代码 代码如下:<?php
class Upload extends Controller {
function go() {
if(isset($_POST['go'])) {
//初始化
$config['upload_path'] = 'album/source';
$config['allowed_types'] = 'gif|jpg|png|bmp|jpeg';
$config['encrypt_name'] = TRUE;
$config['remove_spaces'] = TRUE;
$config['max_size'] = '0';
$config['max_width'] = '0';
$config['max_height'] = '0';

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

//170*170图片
$configThumb = array();
$configThumb['image_library'] = 'gd2';
$configThumb['source_image'] = '';
$configThumb['create_thumb'] = TRUE;
$configThumb['maintain_ratio'] = TRUE; //保持图片比例
$configThumb['new_image'] = 'album/thumb';
$configThumb['width'] = 170;
$configThumb['height'] = 170;
//600*600图片
$configLarge = array();
$configLarge['image_library'] = 'gd2';
$configLarge['source_image'] = '';
$configLarge['create_thumb'] = TRUE;
$configLarge['maintain_ratio'] = TRUE; //保持图片比例
$configLarge['new_image'] = 'album/large';
$configLarge['width'] = 600;
$configLarge['height'] = 600;

$this->load->library('image_lib');

for($i = 1; $i < 6; $i++) {
$upload = $this->upload->do_upload('image'.$i);
if($upload === FALSE) continue;
$data = $this->upload->data();//返回上传文件的所有相关信息的数组
$uid = $this->session->userdata('uid');
$uploadedFiles[$i] = $data;

if($data['is_image'] == 1) {
//初始化170*170
$configThumb['source_image'] = $data['full_path']; //文件路径带文件名
$this->image_lib->initialize($configThumb);
$this->image_lib->resize();
//初始化600*600
$configLarge['source_image'] = $data['full_path']; //文件路径带文件名
$this->image_lib->initialize($configLarge);
$this->image_lib->resize();
}

//插入图片信息到album表,插入的文件名为source目录文件名
$picture = array(
'filename' => $data['file_name'],
'albumID' => $this->uri->segment(4,0),
'uid' => $this->session->userdata('uid'),
'dateline' => time(),
'describe' => '',
'click' => 0
);

$this->load->model('album_model');
$this->album_model->AddPic($picture);
$picture = array();
}
}

$albumID = $this->uri->segment(4);
$backurl = site_url() . 'photo/editpic/album/' .$albumID;
$this->session->set_flashdata('msg','图片上传成功.');
redirect($backurl,'refresh');
}
}

views:new_pic.view文件：

复制代码 代码如下:<form method="post" action="<?php echo site_url() ?>photo/upload/go/<?php echo $albumID ?>" enctype="multipart/form-data">
<input type="file" name="image1" class="files"/><br />
<input type="file" name="image2" class="files"/><br />
<input type="file" name="image3" class="files"/><br />
<input type="file" name="image4" class="files"/><br />
<input type="file" name="image5" class="files"/><br />
<br />
<p><input type="submit" name="go" value="上传照片" class="button" /></p>
</form>

此外需要注意：

1.要一次上传几个文件，修改表单和控制器中循环部分的参数就好。
2.album\\source 是上传后原图目录 large和thumb分别是两次执行$this->image_lib->resize();后存放缩略图的目录
3.缩略图文件名如需和album\\source目录一致，请添加参数 $config['thumb_marker'] = '';
4.$picture这部分数组是保存到数据库的东西，可以不用管了。