使用Django form或api上传图片

对于Web应用程序，以便能够上传文件(资料图片，歌曲，PDF格式，文字……)，它通常是很有用的。下面来看看如何使用Django上传图片。在开始开发图片上传之前，请确保Python的图像库(PIL)已经安装。现在来说明上传图片，我们这里使用Django form结合models的形式上传图片，实现以下几个功能：

Model和ModelForm创建表单
POST上传图片

一、使用ModelForm上传图片

编写Models

首先创建Model，保存上传资料：

# ./polls/models.py
from django.db import models
from django.utils import timezone

class UploadedImageModel(models.Model):
    STATUS_SIZES = (
        (0, '进行中'),
        (1, '已完成'),
    )
    name = models.CharField('名称', max_length=10)
    create_date = models.DateTimeField("时间", default=timezone.now())
    note = models.CharField('备注', max_length=200, blank=True)
    image = models.ImageField('图片', upload_to='photos', blank=False)
    operator = models.CharField('作者', max_length=50, blank=True)
    status = models.IntegerField('状态', default=0, choices=STATUS_SIZES) # 0进行中,1已完成

    class Meta:
         db_table = "uploadedimage"

    def __str__(self):
         return self.name

# ./polls/models.py

from django.db import models

from django.utils import timezone

class UploadedImageModel(models.Model):

STATUS_SIZES = (

(0, '进行中'),

(1, '已完成'),

)

name = models.CharField('名称', max_length=10)

create_date = models.DateTimeField("时间", default=timezone.now())

note = models.CharField('备注', max_length=200, blank=True)

image = models.ImageField('图片', upload_to='photos', blank=False)

operator = models.CharField('作者', max_length=50, blank=True)

status = models.IntegerField('状态', default=0, choices=STATUS_SIZES) # 0进行中,1已完成

class Meta:

db_table = "uploadedimage"

def __str__(self):

return self.name

正如你所看到的，这里的主要区别仅仅是models.ImageField。ImageField字段将确保上传的文件是一个图像。如果不是，格式验证将失败。ImageField使用强制性参数upload_to，这表示硬盘驱动器，图像保存所在的地方。注意，该参数将被添加到settings.py文件中定义的MEDIA_ROOT选项中。

MEDIA_ROOT = '/tmp'

1	MEDIA_ROOT = '/tmp'

model中定义的image的参数upload_to=’photos’，上传的图片将保存至/tmp/photos/目录下。

然后记得要migrate数据库:

$ python manage.py makemigrations polls
$ python manage.py migrate

1 2	$ python manage.py makemigrations polls $ python manage.py migrate

编写Forms

接着建立表单，我们这里使用ModelForm，使模型跟表单紧密关联。

# ./polls/forms.py
from django import forms
from django.utils.timezone import now
from .models import UploadedImage

class UploadedImageForm(forms.ModelForm):

   class Meta:
       model = UploadedImageModel
       fields = '__all__'
       #fields = ['name','create_date','note','image','operator','status']

# ./polls/forms.py

from django import forms

from django.utils.timezone import now

from .models import UploadedImage

class UploadedImageForm(forms.ModelForm):

class Meta:

model = UploadedImageModel

fields = '__all__'

#fields = ['name','create_date','note','image','operator','status']

编写Views

现在我们有表单和模型，让我们来创建视图：

# ./polls/views.py
from django.shortcuts import render
from django.http import HttpResponse, HttpResponseRedirect
from .forms import UploadedImageForm
from .models import UploadedImageModel

def UploadedImageView(request):
    if request.method == "POST":
        form = UploadedImageForm(request.POST, request.FILES)
        if form.is_valid():
            photo = form.save()
            print(photo.image.url)
            return HttpResponseRedirect('/polls/success/')
    else:
        form = UploadedImageForm()
    return render(request, 'polls/upload.html', {'form': form})

def success(request):
    return render(request, 'polls/success.html')

# ./polls/views.py

from django.shortcuts import render

from django.http import HttpResponse, HttpResponseRedirect

from .forms import UploadedImageForm

from .models import UploadedImageModel

def UploadedImageView(request):

if request.method == "POST":

form = UploadedImageForm(request.POST, request.FILES)

if form.is_valid():

photo = form.save()

print(photo.image.url)

return HttpResponseRedirect('/polls/success/')

else:

form = UploadedImageForm()

return render(request, 'polls/upload.html', {'form': form})

def success(request):

return render(request, 'polls/success.html')

视图逻辑大概的意思可以参考：Django上传下载文件

编写urls

url分为两个部分，如下：

# ./mysite/urls.py
from django.conf.urls import url,include
from django.contrib import admin

urlpatterns = [
    url(r'^polls/', include('blog.urls')),
    url(r'^admin/', admin.site.urls),
]

# ./polls/urls.py
from django.conf.urls import url
from . import views

urlpatterns = [
    url(r'^$', views.UploadedImageView),
    url(r'^success/$', views.success),
]

# ./mysite/urls.py

from django.conf.urls import url,include

from django.contrib import admin

urlpatterns = [

url(r'^polls/', include('blog.urls')),

url(r'^admin/', admin.site.urls),

]

# ./polls/urls.py

from django.conf.urls import url

from . import views

urlpatterns = [

url(r'^$', views.UploadedImageView),

url(r'^success/$', views.success),

]

编写templates

views.py中需要的两个html文件放在mysite/templates/polls/目录下。Form要支持上传图片，需要在form中设置enctype=”multipart/form-data”，不设置的话文件不支持上传。

upload.html

<!DOCTYPE html>
<head>
    <meta charset="UTF-8">
    <title>UploadImage</title>
</head>
<body>
    {% if form.errors %}
        <p style="color: red;">
            Please correct the error{{ form.errors|pluralize }} below.
        </p>
    {% endif %}

    <form method="post" action="" enctype="multipart/form-data">
        <table>
        {% csrf_token %}
        {{ form }}
        </table>
       <input type="submit" value="upload"/>
    </form>
</body>
</html>

<!DOCTYPE html>

<head>

<title>UploadImage</title>

</head>

<body>

{% if form.errors %}

Please correct the error{{ form.errors|pluralize }} below.

</p>

{% endif %}

<table>

{% csrf_token %}

</table>

</form>

</body>

</html>

success.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Success!</title>
</head>
<body>
    <div>Success!</div>
</body>
</html>

<!DOCTYPE html>

<head>

<title>Success!</title>

</head>

<body>

<div>Success!</div>

</body>

</html>

到此为止代码都完成了，只需要开启Django server即可。

上传测试

正常情况下，访问http://127.0.0.1:8000/polls/可以看见如下页面：

上传成功后可以在/tmp/photos目录下看见图片，并且在数据库中可以查看到相关信息，其中就包括了图片路径。

二、使用Form类上传图片

上面创建表单是一种比较简洁的方式，直接使用Django提供的ModelForm类；如果不想所有字段保存到数据库，可以使用Form类，属于另一种方式：

编写Forms

from django import forms
from django.utils.timezone import now
from .models import UploadedImageModel

class UploadedImageForm(forms.Form):
    STATUS_SIZES = (
        (0, '进行中'),
        (1, '已完成'),
    )
    name = forms.CharField(label="名称")
    create_date = forms.DateTimeField(label="时间", initial=now())
    note = forms.CharField(label="备注", required=False)
    image = forms.ImageField(label="图片")
    operator = forms.CharField(label="作者")
    status = forms.IntegerField(label="状态", widget=forms.Select(choices=STATUS_SIZES),)

from django import forms

from django.utils.timezone import now

from .models import UploadedImageModel

class UploadedImageForm(forms.Form):

STATUS_SIZES = (

(0, '进行中'),

(1, '已完成'),

)

name = forms.CharField(label="名称")

create_date = forms.DateTimeField(label="时间", initial=now())

note = forms.CharField(label="备注", required=False)

image = forms.ImageField(label="图片")

operator = forms.CharField(label="作者")

status = forms.IntegerField(label="状态", widget=forms.Select(choices=STATUS_SIZES),)

编写Views

from django.shortcuts import render
from django.http import HttpResponse, HttpResponseRedirect
from .forms import UploadedImageForm
from .models import UploadedImageModel

def UploadedImageView(request):
    if request.method == "POST":
        form = UploadedImageForm(request.POST, request.FILES)
        if form.is_valid():
            photo = UploadedImageModel.objects.create(
                name = form.cleaned_data['name'],
                create_date = form.cleaned_data['create_date'],
                note=form.cleaned_data['note'],
                image=form.cleaned_data['image'],
                operator=form.cleaned_data['operator'],
                status=form.cleaned_data['status'],
            )
            photo.save()
            print(photo.image.url)
            return HttpResponseRedirect('/polls/success/')
    else:
        form = UploadedImageForm()
    return render(request, 'polls/upload.html', {'form': form})

def success(request):
    return render(request, 'polls/success.html')

from django.shortcuts import render

from django.http import HttpResponse, HttpResponseRedirect

from .forms import UploadedImageForm

from .models import UploadedImageModel

def UploadedImageView(request):

if request.method == "POST":

form = UploadedImageForm(request.POST, request.FILES)

if form.is_valid():

photo = UploadedImageModel.objects.create(

name = form.cleaned_data['name'],

create_date = form.cleaned_data['create_date'],

note=form.cleaned_data['note'],

image=form.cleaned_data['image'],

operator=form.cleaned_data['operator'],

status=form.cleaned_data['status'],

)

photo.save()

print(photo.image.url)

return HttpResponseRedirect('/polls/success/')

else:

form = UploadedImageForm()

return render(request, 'polls/upload.html', {'form': form})

def success(request):

return render(request, 'polls/success.html')

整个例子对于处理文件上传也是一样的，只需要改变一些数据类型即可。

另外整个例子涉及的Django基础知识还是挺多，比如views、urls、models、templates、forms、modelform等；这里都没细说，可以看Django官网。

三、通过API上传图片

可以通过Django REST framework框架编写API，然后可以通过API来上传图片。

首先需要配置Django静态目录，然后把文件上传到静态目录，不然应该不能直接访问到图片。

修改settings文件，记得注释MEDIA_ROOT配置。

# ./settings
STATIC_URL = '/static/'
STATICFILES_DIRS=[ 
    os.path.join(BASE_DIR,'static')
]

# ./settings

STATIC_URL = '/static/'

STATICFILES_DIRS=[

os.path.join(BASE_DIR,'static')

]

然后对于model的配置就要把图片上传到静态目录了，配置应该如下：

# ./polls/models.py
from django.db import models
from django.utils import timezone

class UploadedImageModel(models.Model):
    STATUS_SIZES = (
        (0, '进行中'),
        (1, '已完成'),
    )
    name = models.CharField('名称', max_length=10)
    create_date = models.DateTimeField("时间", default=timezone.now())
    note = models.CharField('备注', max_length=200, blank=True)
    image = models.ImageField('图片', upload_to='static/images/%Y/%m/%d', blank=False)
    operator = models.CharField('作者', max_length=50, blank=True)
    status = models.IntegerField('状态', default=0, choices=STATUS_SIZES) # 0进行中,1已完成

    class Meta:
         db_table = "uploadedimage"

    def __str__(self):
         return self.name

# ./polls/models.py

from django.db import models

from django.utils import timezone

class UploadedImageModel(models.Model):

STATUS_SIZES = (

(0, '进行中'),

(1, '已完成'),

)

name = models.CharField('名称', max_length=10)

create_date = models.DateTimeField("时间", default=timezone.now())

note = models.CharField('备注', max_length=200, blank=True)

image = models.ImageField('图片', upload_to='static/images/%Y/%m/%d', blank=False)

operator = models.CharField('作者', max_length=50, blank=True)

status = models.IntegerField('状态', default=0, choices=STATUS_SIZES) # 0进行中,1已完成

class Meta:

db_table = "uploadedimage"

def __str__(self):

return self.name

下面就是添加djangoframework相关配置了，首先要安装Djangoframework，具体看：Django REST framework快速入门。

首先在polls应用下创建一个api目录，然后编写serializers.py文件：

# ./polls/api/serializers.py
from rest_framework.serializers import ModelSerializer
from rest_framework import serializers
from polls.models import UploadedImageModel

class UploadImageSerializer(ModelSerializer):

    class Meta:
        model = UploadedImageModel
        fields = ('name','note','image','operator','status')

# ./polls/api/serializers.py

from rest_framework.serializers import ModelSerializer

from rest_framework import serializers

from polls.models import UploadedImageModel

class UploadImageSerializer(ModelSerializer):

class Meta:

model = UploadedImageModel

fields = ('name','note','image','operator','status')

然后提供views.py文件：

# ./polls/api/views.py
from rest_framework import viewsets
from rest_framework.response import Response
from rest_framework import status
from polls.api.serializers import UploadImageSerializer
from polls.models import UploadedImageModel


class UploadImageViewSet(viewsets.ModelViewSet):
    """
    upload image
    """
    def create(self, request, *args, **kwargs):
        self.serializer_class = UploadImageSerializer
        file = request.data.dict()
        # file['image'] = request.FILES.get('image')
        serial = UploadImageSerializer(data=file)
        if not serial.is_valid():
            return Response(status=status.HTTP_400_BAD_REQUEST)

        serial.save()
        return Response(serial.data)

    def list(self, request, *args, **kwargs):
        self.serializer_class = UploadImageSerializer
        self.queryset = UploadedImageModel.objects.all()
        return super(UploadImageViewSet, self).list(request)

# ./polls/api/views.py

from rest_framework import viewsets

from rest_framework.response import Response

from rest_framework import status

from polls.api.serializers import UploadImageSerializer

from polls.models import UploadedImageModel

class UploadImageViewSet(viewsets.ModelViewSet):

"""

upload image

"""

def create(self, request, *args, **kwargs):

self.serializer_class = UploadImageSerializer

file = request.data.dict()

# file['image'] = request.FILES.get('image')

serial = UploadImageSerializer(data=file)

if not serial.is_valid():

return Response(status=status.HTTP_400_BAD_REQUEST)

serial.save()

return Response(serial.data)

def list(self, request, *args, **kwargs):

self.serializer_class = UploadImageSerializer

self.queryset = UploadedImageModel.objects.all()

return super(UploadImageViewSet, self).list(request)

最后添加一些urls路由，如下：

# ./polls/urls.py
from django.conf.urls import url, include
from rest_framework import routers
from . import views
from polls.api.views import *


router = routers.DefaultRouter(trailing_slash=True)
router.register(r'', UploadImageViewSet, base_name='UploadFile')


urlpatterns = [
    url(r'^api/', include(router.urls)),
    url(r'^$/', views.UploadedImageView),
    url(r'^success/$', views.success),
]

# ./polls/urls.py

from django.conf.urls import url, include

from rest_framework import routers

from . import views

from polls.api.views import *

router = routers.DefaultRouter(trailing_slash=True)

router.register(r'', UploadImageViewSet, base_name='UploadFile')

urlpatterns = [

url(r'^api/', include(router.urls)),

url(r'^$/', views.UploadedImageView),

url(r'^success/$', views.success),

]

都完成之后，就可以通过http://127.0.0.1:8000/polls/api/接口进行访问，上传图片了。

然后也可以通过curl命令上传，其格式如下：

$ curl --request POST \
  --header 'content-type: multipart/form-data' \
  --form image=@/tmp/1.png \
  --form name=dkey \
  --form note=upload \
  --form operator=admin \
  --form status=1
  --url http://127.0.0.1:8000/polls/api/