如何修复滚动效果以使按钮仅在滚动后才显示？

Question

Here's the Javascript for the scroll effect

<script type="text/javascript">
$(document).ready(function() {
$(window).scroll(function() {
if($(this).scrollTop() < 200) {
  $(".cta").css({"opacity" : "0"})
}
else {
  $(".cta").css({"opacity" : "1"})
}
})
})
</script>

Here's the CSS for the button to make it sticky

/* call to action in service pages */
a.cta.btn {
    position: fixed;
    right: 4vw;
    bottom: 4vw;
    z-index: 1;
    background: #3e5132;
    color: white;
    border: 2px solid white;
}

a.cta.btn:hover {
    background: white;
    color: #3e5132 !important;
    border: 2px solid #3e5132;
}

Here's the URL of a page with an example. https://new.driveyourdevelopment.com/services/motivational-speaker-denver/

Answer 1

Hi i just tried as below:

 $(document).ready(function() { $(".cta").css({"opacity" : "0"}) $(window).scroll(function() { if($(this).scrollTop() < 200) { $(".btn").removeClass("cta") } else { $(".btn").addClass("cta") } }) }) 

 body { background: #20262E; padding: 20px; color:#fff; font-family: Helvetica; } span { margin-right:20px; color:#fff; } .btn { display: inline-block; padding: 1.5rem 3rem; border: 1px solid black; margin-bottom: 0; font-size: 21px; font-weight: 400; line-height: 1.42857143; text-align: center; white-space: nowrap; vertical-align: middle; -ms-touch-action: manipulation; touch-action: manipulation; cursor: pointer; -webkit-user-select: none; -moz-user-select: none; -ms-user-select: none; user-select: none; background-image: none; border: .15rem solid #3e5132; /* border-radius: 4px; */ } a.btn { position: fixed; opacity:0; right: 4vw; bottom: 4vw; z-index: 1; background: #3e5132; color: white; border: 2px solid white; opacity:0 !important; } a.cta { opacity:1 !important; -webkit-transition: all ease-in-out .5s; transition: all ease-in-out .5s; -webkit-transition: all ease-in-out .5s; } a.btn:hover { background: white; color: #3e5132 !important; border: 2px solid #3e5132; } 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div id="banner-message"> <span>Hello World</span> <span>Hello World</span> <span>Hello World</span> <span>Hello World</span> </div> <a href="#contact" class="btn">Contact Victoria Now</a> <div class="section services" id="section2"> <div class="container"> <div class="heading col-md-12 col-xs-12 services"> <h2>Start Leading Your Business Towards Success</h2> <p></p><p>Are your employees struggling with communication, bad customer service, slow response time, teamwork, or having problems with other people? Yes? That means your employees are having human behavior and communication issues, slowing down the growth of your company. Your company starts to grow when you help your team communicate better with your clients and each other.</p> <p>You help your employees communicate better by teaching them the basics of human behavior and communication. When they understand human behavior and have good communication skills they'll perform at their best.</p> <p>The human element is the number one cause for a company's success or failure. You can have the best resources, tools, procedures, or connections but if your employees don't know how to communicate, your company's in trouble.</p> <p>Helping your team communicate better motivates them to work harder too. They communicate better with your clients but also with each other. Communication skills help build friendships and relationships. If they have good friendships at work, your employees will be more motivated to do a good job and show up to work.</p> <p>To improve your employees' performance and motivate them you need to start thinking about their emotions, problems, aspirations, barriers, and goals. Start getting to know them better. They need more than just a boss or co-worker.</p> <p></p> <h3 class="light hidden-xs">Lead</h3> </div> <!-- heading --> </div> <!-- container --> </div> <div class="section services" id="section2"> <div class="container"> <div class="heading col-md-12 col-xs-12 services"> <h2>Start Leading Your Business Towards Success</h2> <p></p><p>Are your employees struggling with communication, bad customer service, slow response time, teamwork, or having problems with other people? Yes? That means your employees are having human behavior and communication issues, slowing down the growth of your company. Your company starts to grow when you help your team communicate better with your clients and each other.</p> <p>You help your employees communicate better by teaching them the basics of human behavior and communication. When they understand human behavior and have good communication skills they'll perform at their best.</p> <p>The human element is the number one cause for a company's success or failure. You can have the best resources, tools, procedures, or connections but if your employees don't know how to communicate, your company's in trouble.</p> <p>Helping your team communicate better motivates them to work harder too. They communicate better with your clients but also with each other. Communication skills help build friendships and relationships. If they have good friendships at work, your employees will be more motivated to do a good job and show up to work.</p> <p>To improve your employees' performance and motivate them you need to start thinking about their emotions, problems, aspirations, barriers, and goals. Start getting to know them better. They need more than just a boss or co-worker.</p> <p></p> <h3 class="light hidden-xs">Lead</h3> </div> <!-- heading --> </div> <!-- container --> </div> 

If you still have issue let me know

Thank you

Answer 2

Your button class does not start with opacity 0 so it'll be visible from the start. Edit your CSS as followed:

a.cta.btn {
   position: fixed;
   opacity: 0
   right: 4vw;
   bottom: 4vw;
   z-index: 1;
   background: #3e5132;
   color: white;
   border: 2px solid white;
}

you could also use "display: none" as suggested in other answers which will give the same effect. The difference in solutions lies between the animation. Changing opacity can be animated and thus the effect smoothed out, while changing the display attribute happens instantly