上传图片后只显示空白屏幕

Question

http://127.0.0.1/masterlinkci2/admin/cpages/addpicture/33

上传图片1.jpg并按上传文件后，只出现一个空白的白色屏幕，我想知道为什么？

控制器/ Cpages.php

public function addpicture() {

        $gallery_id = $this->uri->segment(3);

        $data['images'] = $this->Mpages->call_slideshow($gallery_id);

        $this->load->view('addpicture', $data); 

    }

视图/ addpicture.php

<label><b>UPLOAD PICTURE</b></label><br><br>

        <div style="margin-left: 35px">
        <fieldset>
            <div class="form-group">
                <div class="row">
                    <div class="col-md-12">
                        <label for="filename" class="control-label">Select File to Upload</label> 
                    </div>
                </div>
            </div>

            <div class="form-group">
                <div class="row">
                    <div class="col-md-12">
                        <input type="file" name="filename" size="20" />
                        <span class="text-danger"><?php if (isset($error)) { echo $error; } ?></span>
                    </div>
                </div>
            </div>

            <div class="form-group">
                <div class="row">
                    <div class="col-md-12">
                        <input type="submit" class="edit" value="Upload File" class="btn btn-primary"/>
                    </div>
                </div>
            </div>
        </fieldset>
        </div>  

控制器/ Cuploadfile.php

//file upload function
    function uploadgallerypic()
    {
        //set preferences
        $config['upload_path'] = './uploads/';
        $config['allowed_types'] = 'jpg|gif';
        $config['max_size']    = '1000000';

        //load upload class library
        $this->load->library('upload', $config);
        $this->load->model('Mpages');


        if (!$this->upload->do_upload('filename'))
        {
            // case - failure
            $upload_error = array('error' => $this->upload->display_errors());
            $this->load->view('addpicture', $upload_error);
        }
        else
        {
            // case - success
            $gallery_id = $this->uri->segment(3);

            $upload_data = $this->upload->data();
            $filename = $upload_data['file_name'];
            $this->Mpages->add_picture_gallery($filename, $gallery_id);

            $data['success_msg'] = '<div class="alert alert-success text-center">Your file <strong>' . $upload_data['file_name'] . '</strong> was successfully uploaded!</div>';
            $this->load->view('addpicture', $data);
        }
    }

任何人都可以帮我解决为什么在按下＆＃34;上传文件＆＃34;屏幕上出现一个空白的白色屏幕？