javascript - 如何使用按钮在 html 中提供自定义警报 oe 条

Question

我需要在加载页面之前显示一些消息，以便发出警报消息，但我无法自定义警报窗口。因此我试图在 html 中实现这一点。但没有取得成功。

我想要一个这样的警报窗口。

图像。

这是我的带有警报的代码。

<script type="text/javascript">
 alert("Hello");
</script>

这是我试图获取窗口的代码。

<frameset rows="20%">
  <frame text="Hello">
</frameset>

在我的框架集中我什么也没得到。我需要使用任何其他标签或其他东西来实现此目的吗？我也需要带有处理程序的按钮，例如警报。

Answer 1

使用下面的代码片段。 fork 自 - http://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_modal

// Get the modal
var modal = document.getElementById('myModal');

// Get the button that opens the modal
var btn = document.getElementById("myBtn");

// Get the <span> element that closes the modal
var okbtn = document.getElementsByClassName("close")[0];

// When the user clicks the button, open the modal 
btn.onclick = function() {
    modal.style.display = "block";
}

// When the user clicks on <span> (x), close the modal
okbtn.onclick = function() {
    modal.style.display = "none";
}

// When the user clicks anywhere outside of the modal, close it
window.onclick = function(event) {
    if (event.target == modal) {
        modal.style.display = "none";
    }
}

.modal {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 1; /* Sit on top */
    padding-top: 100px; /* Location of the box */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgb(0,0,0); /* Fallback color */
    background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
}

/* Modal Content */
.modal-content {
    position: relative;
    background-color: #fefefe;
    margin: auto;
    padding: 0;
    border: 1px solid #888;
    width: 80%;
    box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2),0 6px 20px 0 rgba(0,0,0,0.19);
    -webkit-animation-name: animatetop;
    -webkit-animation-duration: 0.4s;
    animation-name: animatetop;
    animation-duration: 0.4s
}

/* Add Animation */
@-webkit-keyframes animatetop {
    from {top:-300px; opacity:0} 
    to {top:0; opacity:1}
}

@keyframes animatetop {
    from {top:-300px; opacity:0}
    to {top:0; opacity:1}
}

/* The Close Button */
.close {
    color: white;
    float: right;
    font-size: 15px;
    font-weight: bold;
}

.close:hover,
.close:focus {
    color: #000;
    text-decoration: none;
    cursor: pointer;
}

.modal-header {
    padding: 2px 16px;
    background-color: #5cb85c;
    color: white;
}

.modal-body {padding: 2px 16px;}

.modal-footer {
    padding: 2px 16px;
    background-color: #5cb85c;
    color: white;
}

<h2>Animated Modal with Header and Footer</h2>

<!-- Trigger/Open The Modal -->
<button id="myBtn">Open Modal</button>

<!-- The Modal -->
<div id="myModal" class="modal">

  <!-- Modal content -->
  <div class="modal-content">
    <div class="modal-header">
      <h2>Modal Header</h2>
    </div>
    <div class="modal-body">
      <p>Some text in the Modal Body</p>

    </div>
    <div class="modal-footer">
      <button class="close">OK</button> 
    </div>
  </div>

</div>