代码点火器上传映像无法上传到目标目录

我的代码中有什么错误，结果没有出现图像这是我的结果

而这是我的控制器

public function __construct()
    {
        parent::__construct();
        $this->load->model('model_barang'); 
        $this->load->helper('currency_format_helper');  
        $this->load->library(array('pagination','upload')); 
    }
public function index()
{
    $this->load->view('input');
}
public function tampil(){
    $data['barang'] = $this->model_barang->tampil_data()->result();
    $this->load->view('view_barang',$data);
}
public function tambah(){
    $config['upload_path'] = './gambar/';
    $config['allowed_types'] = 'gif|jpg|png';
    $config['max_size'] = '1000';
    $config['max_width']  = '2000';
    $config['max_height']  = '1024';
            $this->upload->initialize($config);
            if(!$this->upload->do_upload('gambar')){
                $gambar="";
            }else{
                $gambar=$this->upload->file_name;
            }
            $info=array(
                'id'=>$this->input->post('id'),
                'jenis'=>$this->input->post('jenis'),
                'nama'=>$this->input->post('nama'),
                'harga'=>$this->input->post('harga'),
                'pemasok'=>$this->input->post('pemasok'),
                'gambar'=>$gambar
            );
            $this->model_barang->input_data($info);
            redirect('barang/tampil');
}
public function hapus($id){
    $where = array('id' => $id);
    $this->model_barang->hapus($where,'barang');
    redirect('barang/tampil');
}
public function edit($id){
    $where = array('id' => $id);
    $data['barang'] = $this->model_barang->edit_data($where,'barang')->result();
    $this->load->view('edit',$data);
}
public function update(){
    $id = $this->input->post('id');
    $jenis = $this->input->post('jenis');
    $nama = $this->input->post('nama');
    $harga = $this->input->post('harga');
    $pemasok = $this->input->post('pemasok');
    $data = array(
        'jenis' => $jenis,
        'nama'=> $nama,
        'harga' => $harga,
        'pemasok' => $pemasok
    );
    $where = array(
        'id' => $id
    );
    $this->model_barang->update($where,$data,'barang');
    redirect('barang/tampil');
}

这是我的模型

private $table="barang";
public function tampil_data(){
    return $this->db->get('barang');
}
public function input_data($jenis){
    $this->db->insert($this->table,$jenis);
    return $this->db->insert_id();
}
public function hapus($where,$table){
    $this->db->where($where);
    $this->db->delete($table);
}
public function edit_data($where,$table) {
    return $this->db->get_where($table,$where);
}
public function update($where,$data,$table){
    $this->db->where($where);
    $this->db->update($table,$data);
}

这是我对输入数据的看法

<form action="<?php echo base_url(). 'index.php/barang/tambah'; ?>" method="post">
    <fieldset>
        <legend><h3>Tambah Data Barang</h3></legend> <br />
            ID Barang <input type="text" name="id" required> <br /> <br />
            Jenis Barang<input type="text" name="jenis" required> <br /> <br />
            Nama Barang<input type="text" name="nama" required> <br /> <br />
            Harga Barang<input type="number" name="harga" required> <br /> <br />
            Pemasok<input type="text" name="pemasok" required> <br /> <br />
            <input type="file" name="gambar"> <br /> <br />
            <button class="tombol">Tambah</button>
    </fieldset>
</form> 

这是我的视图来显示我的数据

<table style="margin:50px auto;" border="1" width="800" height="300">
    <tr>
        <th>No</th>
        <th>ID</th>
        <th>Jenis</th>
        <th>Nama</th>
        <th>harga</th>
        <th>pemasok</th>
        <th>Gambar</th>
        <th>Aksi</th>
    </tr>
    <?php 
    $no = 1;
    foreach($barang as $q){ 
    ?>
    <tr>
        <td><?php echo $no++ ?></td>
        <td><?php echo $q->id ?></td>
        <td><?php echo $q->jenis ?></td>
        <td><?php echo $q->nama ?></td>
        <td><?php echo currency_format($q->harga) ?></td>
        <td><?php echo $q->pemasok ?></td>
        <td><img src="<?php echo base_url('./gambar/'.$q->gambar);?>" height="100px" width="100px"></td>
        <td><?php echo anchor('barang/hapus/'.$q->id,'Hapus', ['onclick'=>'return confirm(''Apakah Anda Yakin'')'] ); ?> | <?php echo anchor('barang/edit/'.$q->id,'Edit') ?></td>      
    </tr>
    <?php } ?>
</table>

这是我的数据库

这是我的数据

帮助在显示数据中显示图像