简单实例 与 按钮制作
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
上传文件 enctype="multipart/form-data
<form method="POST" enctype="multipart/form-data">
{% csrf_token %}
<input type="file" name="img">
<button type="submit">上传</button>
</form>