这是我的错误

Severity: Notice

Message: Trying to get property of non-object

Filename: admin/nilai_daftar.php

Line Number: 10

Backtrace:

File: C:\xampp\htdocs\siakad\application\views\admin\nilai_daftar.php
Line: 10
Function: _error_handler

File: C:\xampp\htdocs\siakad\application\controllers\admin\nilai.php
Line: 128
Function: view

File: C:\xampp\htdocs\siakad\index.php
Line: 315
Function: require_once

A PHP Error was encountered
Severity: Notice

Message: Trying to get property of non-object

Filename: admin/nilai_daftar.php

Line Number: 11

Backtrace:

File: C:\xampp\htdocs\siakad\application\views\admin\nilai_daftar.php
Line: 11
Function: _error_handler

File: C:\xampp\htdocs\siakad\application\controllers\admin\nilai.php
Line: 128
Function: view

File: C:\xampp\htdocs\siakad\index.php
Line: 315
Function: require_once

查看（nilai_form.php）

    <form method="post" action="<?php echo base_url() ?>admin/nilai/simpan_nilai">
    <table class="table table-striped table-hover table-bordered mt-4">
        <tr>
            <td>No</td>
            <td>NIM</td>
            <td>Nama</td>
            <td>Nilai</td>
        </tr>
        <?php 
            $no = 1;
            foreach ($list_nilai as $row ) : ?>
        <tr>
            <td width="25px"><?php echo $no++ ?></td>
            <td><?php echo $row->nim ?></td>
            <td><?php echo $row->nama_lengkap ?></td>
            <input type="hidden" name="id_krs[]" value="<?php $row->id_krs; ?>">
            <td width="20px"><input type="text" name="nilai[]" class="form-control" value="<?php echo $row->nilai; ?>"></td>
        </tr>
        <?php endforeach; ?>
    </table>
    <button type="submit" class="btn btn-primary">Simpan</button>
</form>

在nilai_daftar.php中（查看）

<?php 

$nilai = get_instance();
$nilai->load->model('model_krs');
$nilai->load->model('model_mahasiswa');
$nilai->load->model('model_matkul');
$nilai->load->model('model_tahunakademik');

$krs = $nilai->model_krs->getbyid($id_krs[0]);
$kode_matkul = $krs->kode_matkul;
$id_thn_akad = $krs->id_thn_akad;

？>

still nilai_daftar.php（查看）

 <div class="container-fluid">
<div class="alert alert-primary"><i class="fa fa-file"></i>Daftar Nilai Mahasiswa</div>

    <center>
        <legend><strong>DAFTAR NILAI MAHASISWA</strong></legend>
            <table>
                <tr>
                    <td>Kode Mata Kuliah</td>
                    <td>: <?php echo $kode_matkul; ?></td>
                </tr>

                </table>

在nilai.php（控制器）中

public function simpan_nilai() {
        $query = array ();
            $id_krs = $_POST['id_krs'];
            $nilai = $_POST['nilai'];

            for($i=0; $i>sizeof($id_krs); $i++) {
                $this->db->set('nilai',$nilai[$i])->where('id_krs',$id_krs[$i])->update('krs'); //tabel krs
            }
            $data = array(
                'id_krs' => $id_krs
            );
            $this->load->view('templates_admin/header');
            $this->load->view('templates_admin/sidebar');
            $this->load->view('admin/nilai_daftar',$data);
            $this->load->view('templates_admin/footer');
    }