防止多次点击刷屏操作

templates/article.html

@@ -72,6 +72,7 @@
     }
 
 </script>
+
 {% endblock %}
 
 
@@ -130,8 +131,21 @@ <h2 class="card-title">{{ article.title }}</h2><!--title-->
           <textarea class="form-control" rows="3" name="body" placeholder="write something here..." required="required"></textarea>
         </div>
 
-        <button class="btn btn-primary" type="submit" style="float:right">comment</button>
+        <button id="btn" class="btn btn-primary" type="submit" style="float:right"  onClick="prevent()">comment</button>
     </form>
+    <script type="text/javascript">
+        // 第一种 通过点击事件
+        var clicktag = 1;
+        btn.onclick = function () {
+            if (clicktag == 3) {
+                alert("请勿频繁点击！");
+                setTimeout(function () { clicktag = 0 }, 5000);
+            } else {
+                clicktag = clicktag + 1;
+            }
+        }
+
+    </script>
 </div>
 </div><br>