无法理解烧瓶如何使用 url_for答案

【问题标题】：Unable to understand how flask uses url_for无法理解烧瓶如何使用 url_for
【发布时间】：2018-04-24 09:36:31
【问题描述】：

我有一个非常简单的用例。我已经从链接下载了烧瓶干净的博客文件：https://startbootstrap.com/template-overviews/clean-blog/，我的目的是建立一个博客网站。

对于初学者，我只是尝试使用一个非常简单的脚本来加载索引页面：

Test.py：

from flask import Flask,render_template

app = Flask(__name__)

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

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

我有以下模块结构：

C:.
│   Test.py
│
├───static
│   └───css
│           bootstrap.min.css
│           clean-blog.min.css
│           font-awesome.min.css
│
└───templates
        index.html

现在我的 index.html 文件如下：

<!DOCTYPE html>
<html lang="en">

  <head>

    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    <meta name="description" content="">
    <meta name="author" content="">

    <title>Clean Blog - Start Bootstrap Theme</title>

    <!-- Bootstrap core CSS -->
    <link rel="stylesheet" href="{{ url_for('static',filename='css/bootstrap.min.css') }}" >

    <!-- Custom fonts for this template -->
    <link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='css/font-awesome.min.css') }}"  >
    <link rel='stylesheet' href='https://fonts.googleapis.com/css?family=Lora:400,700,400italic,700italic'  type='text/css'>
    <link href='https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800' rel='stylesheet' type='text/css'>

    <!-- Custom styles for this template -->
    <link rel="stylesheet" href="{{ url_for('static',filename='css/clean-blog.min.css') }}" >

  </head>

  <body>

    <!-- Navigation -->
    <nav class="navbar navbar-expand-lg navbar-light fixed-top" id="mainNav">
      <div class="container">
        <a class="navbar-brand" href="index.html">Start Bootstrap</a>
        <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarResponsive" aria-controls="navbarResponsive" aria-expanded="false" aria-label="Toggle navigation">
          Menu
          <i class="fa fa-bars"></i>
        </button>
        <div class="collapse navbar-collapse" id="navbarResponsive">
          <ul class="navbar-nav ml-auto">
            <li class="nav-item">
              <a class="nav-link" href="index.html">Home</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="about.html">About</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="post.html">Sample Post</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="contact.html">Contact</a>
            </li>
          </ul>
        </div>
      </div>
    </nav>

    <!-- Page Header -->
    <header class="masthead" style="background-image: url('img/home-bg.jpg')">
      <div class="overlay"></div>
      <div class="container">
        <div class="row">
          <div class="col-lg-8 col-md-10 mx-auto">
            <div class="site-heading">
              <h1>Clean Blog</h1>
              <span class="subheading">A Blog Theme by Start Bootstrap</span>
            </div>
          </div>
        </div>
      </div>
    </header>

    <!-- Main Content -->
    <div class="container">
      <div class="row">
        <div class="col-lg-8 col-md-10 mx-auto">
          <div class="post-preview">
            <a href="post.html">
              <h2 class="post-title">
                Man must explore, and this is exploration at its greatest
              </h2>
              <h3 class="post-subtitle">
                Problems look mighty small from 150 miles up
              </h3>
            </a>
            <p class="post-meta">Posted by
              <a href="#">Start Bootstrap</a>
              on September 24, 2018</p>
          </div>
          <hr>
          <div class="post-preview">
            <a href="post.html">
              <h2 class="post-title">
                I believe every human has a finite number of heartbeats. I don't intend to waste any of mine.
              </h2>
            </a>
            <p class="post-meta">Posted by
              <a href="#">Start Bootstrap</a>
              on September 18, 2018</p>
          </div>
          <hr>
          <div class="post-preview">
            <a href="post.html">
              <h2 class="post-title">
                Science has not yet mastered prophecy
              </h2>
              <h3 class="post-subtitle">
                We predict too much for the next year and yet far too little for the next ten.
              </h3>
            </a>
            <p class="post-meta">Posted by
              <a href="#">Start Bootstrap</a>
              on August 24, 2018</p>
          </div>
          <hr>
          <div class="post-preview">
            <a href="post.html">
              <h2 class="post-title">
                Failure is not an option
              </h2>
              <h3 class="post-subtitle">
                Many say exploration is part of our destiny, but it’s actually our duty to future generations.
              </h3>
            </a>
            <p class="post-meta">Posted by
              <a href="#">Start Bootstrap</a>
              on July 8, 2018</p>
          </div>
          <hr>
          <!-- Pager -->
          <div class="clearfix">
            <a class="btn btn-primary float-right" href="#">Older Posts &rarr;</a>
          </div>
        </div>
      </div>
    </div>

    <hr>

    <!-- Footer -->
    <footer>
      <div class="container">
        <div class="row">
          <div class="col-lg-8 col-md-10 mx-auto">
            <ul class="list-inline text-center">
              <li class="list-inline-item">
                <a href="#">
                  <span class="fa-stack fa-lg">
                    <i class="fa fa-circle fa-stack-2x"></i>
                    <i class="fa fa-twitter fa-stack-1x fa-inverse"></i>
                  </span>
                </a>
              </li>
              <li class="list-inline-item">
                <a href="#">
                  <span class="fa-stack fa-lg">
                    <i class="fa fa-circle fa-stack-2x"></i>
                    <i class="fa fa-facebook fa-stack-1x fa-inverse"></i>
                  </span>
                </a>
              </li>
              <li class="list-inline-item">
                <a href="#">
                  <span class="fa-stack fa-lg">
                    <i class="fa fa-circle fa-stack-2x"></i>
                    <i class="fa fa-github fa-stack-1x fa-inverse"></i>
                  </span>
                </a>
              </li>
            </ul>
            <p class="copyright text-muted">Copyright &copy; Your Website 2018</p>
          </div>
        </div>
      </div>
    </footer>

    <!-- Bootstrap core JavaScript -->
    <script src="vendor/jquery/jquery.min.js"></script>
    <script src="vendor/bootstrap/js/bootstrap.bundle.min.js"></script>

    <!-- Custom scripts for this template -->
    <script src="js/clean-blog.min.js"></script>

  </body>

</html>

我不知道为什么，但这似乎不起作用。导航栏不可见。

当我换行时更奇怪：

<link rel="stylesheet" href="{{ url_for('static',filename='css/bootstrap.min.css') }}" >
<link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='css/font-awesome.min.css') }}"  >
<link rel="stylesheet" href="{{ url_for('static',filename='css/clean-blog.min.css') }}" >

到

<link rel="stylesheet" href="{{ url_for('static',filename='bootstrap.min.css') }}" >
<link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='font-awesome.min.css') }}"  >
<link rel="stylesheet" href="{{ url_for('static',filename='clean-blog.min.css') }}" >

一切正常，我可以看到缩进和导航栏正常工作。理想情况下它不应该工作，因为 css 文件位于 /static/css 文件夹中，而不是直接在 static 下。

谁能告诉我这里有什么问题？

提前致谢。

【问题讨论】：

当您查看呈现的 HTML 的源代码（在您的浏览器中）时，URL 看起来是否正确？可以在浏览器中直接访问 .css 吗？
是的。那更奇怪不是吗？网址类似于：/static/bootstrap.min.css。当我单击它时，css 会加载。
看起来你的静态目录位于static/css/而不是static/
试试这个：stackoverflow.com/a/43347682/651299

标签： html css flask bootstrap-4

【解决方案1】：

您的路径/文件夹中似乎有问题：Flask 似乎正在从 static/css/ 而不是 static/ 提供文件。

尝试使用这些参数：

app = Flask(__name__, static_url_path='/static',static_folder='static/')

【讨论】：

这个暂时解决了。我清除了 cookie 和临时文件并按预期开始工作。非常奇怪。