如何在将BLOB图像加载到html页面时去掉b''前缀？

Question

当我尝试加载用户提交到数据库的图像数据时，它确实会使图像源与该数据相等，但它的前缀为b“”，因此不会显示图像。如何删除它以便显示图像？你知道吗

我试过在上传到数据库时从utf-8解码它，但它不起作用，因为它被存储为BLOB，所以会出现二进制错误。我在使用inspect元素时手动删除了b“”，然后它会显示图像。你知道吗

@app.route('/imagePost', methods=['POST'])
def imagePost():

    POST_IMAGE_TITLE = str(request.form['imageTitle'])
    POST_IMAGE_DESC = str(request.form['imageDescription'])
    image = request.files['file']
    image = b64encode(image.read())


    Session = sessionmaker(bind=engine)
    s = Session()

    userID = session['userID']
    Username = session['logged_user']

    currentDT = datetime.datetime.now()
    currentDT = currentDT.strftime("%Y-%m-%d %H:%M:%S")

    #make text post
    imagePost = Image(POST_IMAGE_TITLE, POST_IMAGE_DESC, image, userID,Username,currentDT)
    s.add(imagePost)
    s.commit()

    return home()

from flask import Flask
from sqlalchemy.orm import sessionmaker
from flask import Flask, flash, redirect, render_template, request, session, abort
from base64 import b64encode
import base64
import os

import datetime
# this will allow us to access the orm objects
from setDB import *

# creates database engine to database location
engine = create_engine('sqlite:///myDatabase.db', echo=True)

# creates an instance of Flask 
app = Flask(__name__)

# route decorator for the default path
@app.route('/')
def home():
    if not session.get('logged_in'):
        return render_template('login.html')
    else:
        users = []
        posts = []
        iPosts = []
        Session = sessionmaker(bind=engine)
        s = Session()
        posts = s.query(Text).order_by(desc(Text.time)).all() # https://stackoverflow.com/questions/4186062/sqlalchemy-order-by-descending
        iPosts = s.query(Image).order_by(desc(Image.time)).all()
        if request.form:
            try:
                users = s.query(User)
            except Exception as e:
                print("Failed to fetch users")
                print(e)
        return render_template("welcome.html", users=users, posts=posts, iPosts=iPosts, userID=session['userID'])

在页面上显示时：

<div class="col-sm-4">
                {% for ipost in iPosts %}
                <h3 class="mt-5">{{ ipost.imageTitle }}</h3>
                <p3 class="lead">{{ipost.imageDescription}}</p3>
                <img src="data:image/jpeg;base64,{{ ipost.image }}" alt="image for post"> <!---get rid of b' prefix -->
                <br></br>
                <small>{{ipost.Username}}</small>
                <small>{{ipost.time}}</small>
                <br><hr size=1></br>
                {% endfor %}
            </div>

我希望它能显示它，并且图像源没有b''前缀，但它确实有。你知道吗

Answer 1

您需要decode要str的字节，因此这应该可以工作：

<img src="data:image/jpeg;base64,{{ ipost.image.decode('ascii') }}"

如果cod运行在默认编码不是ASCII的超集（或接近超集）的环境中，那么将编码指定为ASCII将适用于base64编码的文本，并防止出现错误。你知道吗