fix bug(关闭标签页后重新打开，显示还有之前上传的文件名)

templates/simple_backtest.html

@@ -1,52 +1,61 @@
 {% extends "base_index.html" %}
 {% block content %}
-    <div class="container mt-5">
-        <h1 class="text-center mb-4">上传CSV文件</h1>
-        <div class="row justify-content-center">
-            <div class="col-md-6">
-                <form action="/simple_backtest" method="post" enctype="multipart/form-data" class="mb-3">
-                    <div class="input-group mb-3">
-                        <div class="custom-file">
-                            <input type="file" class="custom-file-input" name="file" id="fileInput"
-                                   onchange="updateLabel()">
-                            <label class="custom-file-label" for="fileInput">选择文件</label>
-                        </div>
-                        <div class="input-group-append">
-                            <button class="btn btn-outline-secondary" type="submit">上传</button>
-                        </div>
+<div class="container mt-5">
+    <h1 class="text-center mb-4">上传CSV文件</h1>
+    <div class="row justify-content-center">
+        <div class="col-md-6">
+            <form action="/simple_backtest" method="post" enctype="multipart/form-data" class="mb-3">
+                <div class="input-group mb-3">
+                    <div class="custom-file">
+                        <input type="file" class="custom-file-input" name="file" id="fileInput"
+                               onchange="updateLabel()">
+                        <label class="custom-file-label" for="fileInput">选择文件</label>
                     </div>
-                </form>
-            </div>
+                    <div class="input-group-append">
+                        <button class="btn btn-outline-secondary" type="submit">上传</button>
+                    </div>
+                </div>
+            </form>
         </div>
+    </div>
 
-        {% if tables %}
-            <h2 class="text-center">{{ file_name }}分析结果</h2>
-            <div class="table-responsive">
-                {% for table in tables %}
-                    {{ table|safe }}
-                {% endfor %}
-            </div>
-        {% endif %}
+    {% if tables %}
+    <h2 class="text-center">{{ file_name }}分析结果</h2>
+    <div class="table-responsive">
+        {% for table in tables %}
+        {{ table|safe }}
+        {% endfor %}
     </div>
+    {% endif %}
+</div>
 
-    <script>
-        // 当文件选择变化时，保存文件名到本地存储
-        function updateLabel() {
-            var input = document.getElementById('fileInput');
+<script>
+    // 当文件选择变化时，保存文件名到本地存储
+    function updateLabel() {
+        var input = document.getElementById('fileInput');
+        if (input.files.length > 0) {  // 确保选择了文件
             var label = input.nextElementSibling;
             var fileName = input.files[0].name;
             label.innerHTML = fileName;
             localStorage.setItem('lastUploadedFileName', fileName); // 保存文件名到本地存储
+        } else {
+            localStorage.removeItem('lastUploadedFileName'); // 如果没有文件被选择，清除存储的文件名
+        }
+    }
+
+    // 页面加载完成后，检查是否有保存的文件名
+    document.addEventListener('DOMContentLoaded', function () {
+        var input = document.getElementById('fileInput');
+        var label = document.querySelector('.custom-file-label');
+        if (input.files.length > 0) {  // 如果实际上有文件被选中
+            var fileName = input.files[0].name;
+            label.innerHTML = fileName;
+        } else {
+            label.innerHTML = '选择文件';  // 如果没有文件，显示默认文本
+            localStorage.removeItem('lastUploadedFileName'); // 清除本地存储中的文件名
         }
+    });
 
-        // 页面加载完成后，检查是否有保存的文件名
-        document.addEventListener('DOMContentLoaded', function () {
-            var lastFileName = localStorage.getItem('lastUploadedFileName');
-            if (lastFileName) {
-                var label = document.querySelector('.custom-file-label');
-                label.innerHTML = lastFileName;
-            }
-        });
-    </script>
+</script>
 
 {% endblock %}