2023.11.22使用flask做一个简单的图片浏览器

功能：
实现图片浏览（翻页）功能

注意：在flask中常会使用src=“{{ url_for(‘static’, filename=‘image s/’ + image) }}”，这段代码是在Flas k 框架中用于获取静态文件的URL的。在Flas k中，静态文件通常存放在static 文件夹中，比如CSS、Jav aSc rip t或者图片文件等。url_for(‘static’, file name=‘image s/’ + image)这段代码会生成一个对应静态文件的URL，其中’static’是指定静态文件夹的名称，‘im a g es/’ + im a ge是指定文件夹中图片的路径。

如果im a ge是一个变量，那么在渲染模板的时候就会根据实际的im age的值来生成对应的URL。这个URL可以在前端页面中引用，用于加载静态图片文件。

import os
from flask import Flask, render_template, request

app = Flask(__name__)

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/preview', methods=['POST'])
def preview():
    image_name = request.form['image_name']
    image_dir = os.path.dirname(os.path.abspath(__file__)) + '/static/uploads'
    image_list = sorted(os.listdir(image_dir))
    current_index = image_list.index(image_name)
    prev_index = current_index - 1 if current_index &gt; 0 else None
    next_index = current_index + 1 if current_index &lt; len(image_list) - 1 else None
    prev_image_name = image_list[prev_index] if prev_index is not None else None
    next_image_name = image_list[next_index] if next_index is not None else None
    image_url = f'/static/uploads/{image_name}'
    return render_template('preview.html', image_name=image_name, image_url=image_url, prev_image_name=prev_image_name, next_image_name=next_image_name)

if __name__ == '__main__':
    app.run(debug=True)

<!DOCTYPE html>
<html>
<head>
    <title>Image Preview</title>
    <link href="https://cdn.staticfile.org/twitter-bootstrap/5.1.1/css/bootstrap.min.css" rel="stylesheet">
    <script src="https://cdn.staticfile.org/twitter-bootstrap/5.1.1/js/bootstrap.bundle.min.js"></script>
    <style>
        body {
            padding: 20px;
        }
        img {
            height: 200px;
            width: 200px;
        }
    </style>
</head>
<body>
    <h2>Image Preview: {{ image_name }}</h2>
    <div>
        <img src="{{ image_url }}" class="img-fluid" alt="Preview">
    </div>
    <div class="btn-group mt-2" role="group" aria-label="Image Navigation">
        <form action="/preview" method="post">
            {% if prev_image_name %}
                <input type="hidden" name="image_name" value="{{ prev_image_name }}">
                <input type="submit" class="btn btn-primary" value="Prev">
            {% endif %}
        </form>
        <form action="/preview" method="post">
            {% if next_image_name %}
                <input type="hidden" name="image_name" value="{{ next_image_name }}">
                <input type="submit" class="btn btn-primary" value="Next">
            {% endif %}
        </form>
    </div>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
    <title>Image Preview</title>
</head>
<body>
    <h2>Enter Image Name</h2>
    <form action="/preview" method="post">
        <input type="text" name="image_name" placeholder="Enter Image Name">
        <button type="submit">Preview</button>
    </form>
</body>
</html>