Flask App - 为什么我只得到一个占位符选择而不是上传的图像？

Question

我创建了一个 Flask 应用来上传图像以预测其标签。这是app.py相关部分的代码：

@app.route("/", methods=['GET', 'POST'])
def main():
    return render_template("index.html")

@app.route("/submit", methods = ['GET', 'POST'])
def get_output():
    if request.method == 'POST':
        img = request.files['my_image']

        licenseplate = "static/" + img.filename 
        img.save(licenseplate)

        p = predictLicensePlate(licenseplate)

这是index.html:

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Number Plate Recognition</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"></script>
</head>
<body>

<div class="container">
  <h1 class="jumbotron bg-primary">Number Plate Recognition</h1>
  <br><br>
  <form class="form-horizontal" action="/submit" method="post" enctype="multipart/form-data">

    <div class="form-group">
      <label class="control-label col-sm-2" for="pwd">Upload Your Image :</label>
      <div class="col-sm-10">          
        <input type="file" class="form-control" placeholder="Hours Studied"  name="my_image" id="pwd">
      </div>
    </div>

    <div class="form-group">        
      <div class="col-sm-offset-2 col-sm-10">
        <button type="submit" class="btn btn-success">Submit</button>
      </div>
    </div>
  </form>

    {% if prediction %}
  <img src="{{img_path}}" height="200px" width="300px">
    <h2> Your Prediction   : <i> {{prediction}} </i></h2>

    {% endif %}

</div>







</body>
</html>

但是当我上传图片时，我只会在那里看到一个占位符图片，如下所示。你能找出我的代码有什么问题吗？我的图片格式是png，预测没问题。

Answer 1

您需要在模板中设置 img_path 变量：

 <img src="{{img_path}}" height="200px" width="300px">

Flask App - 为什么我只得到一个占位符选择而不是上传的图像？

Flask App - why do I just get a placeholder pick instead of uploaded image?

html

python

image

flask