# 創(chuàng)建Download項目
django-admin startproject Download
# 創(chuàng)建down_app app
python manage.py startapp down_app

import os
from django.http import HttpResponse
from django.http import StreamingHttpResponse


def image_down(request):
    """
    下載圖片
    """
    img_name = request.GET.get("username") + ".png"  # 二維碼圖片名
    base_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))  # 項目根目錄
    file_path = os.path.join(base_dir, 'antirisk/CodeGenerate/image/code', img_name)  # 二維碼的絕對路徑

    if not os.path.isfile(file_path):  # 判斷下載文件是否存在
        return HttpResponse("Sorry but Not Found the File")

    def file_iterator(file_path, chunk_size=512):
        """
        文件生成器,防止文件過大，導致內(nèi)存溢出
        :param file_path: 文件絕對路徑
        :param chunk_size: 塊大小
        :return: 生成器
        """
        with open(file_path, mode='rb') as f:
            while True:
                c = f.read(chunk_size)
                if c:
                    yield c
                else:
                    break

    try:
        # 設置響應頭
        # StreamingHttpResponse將文件內(nèi)容進行流式傳輸，數(shù)據(jù)量大可以用這個方法
        response = StreamingHttpResponse(file_iterator(file_path))
        # 以流的形式下載文件,這樣可以實現(xiàn)任意格式的文件下載
        response['Content-Type'] = 'application/octet-stream'
        # Content-Disposition就是當用戶想把請求所得的內(nèi)容存為一個文件的時候提供一個默認的文件名
        response['Content-Disposition'] = f'attachment;filename="1.png"'  # 文件名不可設置為中文
    except:
        return HttpResponse("Sorry but Not Found the File")

    return response

from django.contrib import admin
from django.urls import path, re_path
from down_app import views

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', views.index),
    re_path('download/)', views.image_down, name="download"),
]

!DOCTYPE html>
html lang="en">
head>
    meta charset="UTF-8">
    title>Title/title>
/head>
body>
a href="/download/" rel="external nofollow" >下載圖片/a>
/body>
/html>

# 運行項目
python manage.py runserver