我无法将图像显示在页面上。我可以存储它。

这些是处理程序：

class disp_image(webapp.RequestHandler):
    def get(self):
        key = self.request.get('key')
        image = Images.get(key)
        if image:
            self.response.headers['Content-Type'] = "image/png"
            return self.response.out.write(images.image)
        else:
            self.response.headers['Content-Type'] = "image/png"
            return self.response.out.write("/static/unknown.gif")

class Profile(MainHandler):
    def get(self):      
        if self.user:
            self.render('profile.html', username = self.user.name, email = self.user.email, first_name = self.user.first_name, last_name = self.user.last_name, country = self.user.country, prov_state = self.user.prov_state, city_town = self.user.city_town)
        else:
            self.redirect('/register')

class Change_Profile_Image(MainHandler):
    def get(self):
        if self.user:
            self.render('change_profile_image.html', username = self.user.name, firstname=self.user.first_name)
        else:
            self.render('change_profile_image.html')

    def post(self):
        images = Images()
        imageupl = self.request.get('img')
        images.image = db.Blob(imageupl)
        images.put()
        self.redirect('/profile')

db的内容如下：

class Images(db.Model):
    image = db.BlobProperty()

class User(db.Model):
    name = db.StringProperty(required=True)
    pw_hash = db.StringProperty(required=True)
    email = db.StringProperty(required=True)
    first_name = db.StringProperty()
    last_name = db.StringProperty()
    country = db.StringProperty()
    prov_state = db.StringProperty()
    city_town= db.StringProperty()
    clan= db.StringProperty()
    handle= db.StringProperty()

表格：

<form enctype="multipart/form-data" method="post">
       <input type="file" name="img" />
</form>

我的模板替换代码：

<img src="/disp?key={{image}}" /></img>