[Django学习]前端+后端两种方式处理图片流数据

方式1：数据库存放图片地址,图片存放在Django项目文件中

1.首先，我们现在models.py文件中定义模型来存放该图片数据,前端传来的数据都会存放在Django项目文件里的images文件夹下

from django.db import models

class Image(models.Model):
    title = models.CharField(max_length=100)
    image = models.ImageField(upload_to='images/')
    uploaded_at = models.DateTimeField(auto_now_add=True)
    
    def __str__(self):
        return self.title

2.下一步，在settings.py文件里配置媒体文件上传

import os

MEDIA_URL = '/media/'
MEDIA_ROOT = os.path.join(BASE_DIR, 'media')

3.在forms.py文件中创建表单

from django import forms
from .models import Image

class ImageForm(forms.ModelForm):
    class Meta:
        model = Image
        fields = ['title', 'image']

4.在视图文件里增加两个函数，一个是用来前端给后端传图片流数据，后端进行处理；另一个是后端从数据库中调出图片返还给前端

from django.shortcuts import render, redirect
from .forms import ImageForm
from .models import Image

def upload_image(request):
    if request.method == 'POST':
        form = ImageForm(request.POST, request.FILES)
        if form.is_valid():
            form.save()
            return redirect('image_list')
    else:
        form = ImageForm()
    return render(request, 'upload_image.html', {'form': form})

def image_list(request):
    images = Image.objects.all()
    return render(request, 'image_list.html', {'images': images})

5.前端upload_image.html文件。这里为了体现出主要功能，所以写的有些简陋。

<!DOCTYPE html>
<html>
<head>
    <title>上传图片</title>
</head>
<body>
    <h1>图片上传</h1>
    <form method="post" enctype="multipart/form-data">
        {% csrf_token %}
        {{ form.as_p }}
        <button type="submit">确认上传</button>
    </form>
</body>
</html>

6.前端image_list.html文件.

<!DOCTYPE html>
<html>
<head>
    <title>图片展示</title>
</head>
<body>
    <h1>图片列表</h1>
    <ul>
        {% for image in images %}
            <li>
                <h2>{{ image.title }}</h2>
                <img src="{{ image.image.url }}" alt="{{ image.title }}" style="width: 200px; height: auto;">
            </li>
        {% endfor %}
    </ul>
</body>
</html>

7.在urls.py文件中完成相关配置

from django.urls import path
from django.conf import settings
from django.conf.urls.static import static
from .views import upload_image, image_list

urlpatterns = [
    path('upload/', upload_image, name='upload_image'),
    path('images/', image_list, name='image_list'),
] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

8.最后一步，基础操作，完成创建和应用数据库迁移，运行查看结果

python manage.py makemigrations
python manage.py migrate

python manage.py runserver

方式1流程及效果展示

前后端完整过程为：前端填写图片标题等信息，之后选择图片并传给后端，后端把前端传过来的图片保存在当前项目文件中，并在数据库中存放图片的位置。前端想要查看图片，后端先从数据库中调出图片的位置信息，之后把位置信息传给前端，前端src展示出图片

前端选择并上传图片

后端返还图片

数据库中存放的数据

Django项目文件结构

方式2：数据库直接存放base64转码后的数据，随调随用

1.编写模型,同上

class Base64Image(models.Model):
    title = models.CharField(max_length=100)
    image_data = models.TextField()  # 用于存储base64编码的图片数据

    def __str__(self):
        return self.title

2.编写表单

class Base64ImageForm(forms.Form):
    title = forms.CharField(max_length=100)
    image = forms.ImageField()

3.编写视图(在views.imageBase64.py中编写)

import base64
from django.shortcuts import render, redirect
from app01.forms import Base64ImageForm
from app01.models import Base64Image

def upload_base64_image(request):
    if request.method == 'POST':
        form = Base64ImageForm(request.POST, request.FILES)
        if form.is_valid():
            title = form.cleaned_data['title']
            image = form.cleaned_data['image']
            image_data = base64.b64encode(image.read()).decode('utf-8')
            Base64Image.objects.create(title=title, image_data=image_data)
            return redirect('image_list')
    else:
        form = Base64ImageForm()
    return render(request, 'upload_base64_image.html', {'form': form})

def image_list(request):
    images = Base64Image.objects.all()
    return render(request, 'image_list.html', {'images': images})

4.前端代码,upload_base64_image.html

<!DOCTYPE html>
<html>
<head>
    <title>上传Base64图片</title>
</head>
<body>
    <h2>测试上传</h2>
    <form method="post" enctype="multipart/form-data">
        {% csrf_token %}
        {{ form.as_p }}
        <button type="submit">上传</button>
    </form>
</body>
</html>

5.前端代码,image_list.html

<!DOCTYPE html>
<html>
<head>
    <title>base64图片张氏</title>
</head>
<body>
    <h2>图片列表</h2>
    <ul>
        {% for image in images %}
            <li>
                <h3>{{ image.title }}</h3>
                <img src="data:image/jpeg;base64,{{ image.image_data }}" alt="{{ image.title }}">
            </li>
        {% endfor %}
    </ul>
</body>
</html>

6.url文件中配置相关路径，同上省略