javascript - 在指定位置弹出

Question

我正在关注 this W3Schools page创建模式弹出窗口。以下代码是从原始页面复制的。

HTML:

<input id="myInputTextBox" />

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

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

  <!-- Modal content -->
  <div class="modal-content">
    <span class="close">&times;</span>
    <p>Some text in the Modal..</p>
  </div>

</div> 

风格:

 /* The Modal (background) */
.modal {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 1; /* Sit on top */
    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/Box */
.modal-content {
    background-color: #fefefe;
    margin: 15% auto; /* 15% from the top and centered */
    padding: 20px;
    border: 1px solid #888;
    width: 80%; /* Could be more or less, depending on screen size */
}

/* The Close Button */
.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

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

Javascript:

// 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 span = document.getElementsByClassName("close")[0];

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

// When the user clicks on <span> (x), close the modal
span.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";
    }
} 

如何根据视口(viewport)中的可用空间将此弹出窗口定位在 myInputTextBox 的下方或上方？请注意，我需要能够处理模式上的点击事件，这样，如果点击发生在模型内容之外，我将关闭弹出窗口。

Answer 1

这是一个基于 CSS 的解决方案:

// 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 span = 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
        span.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 {
            background-color: #fefefe;
            margin: auto;
            padding: 20px;
            border: 1px solid #888;
            width: 80%;
            left: 8px;
            position: absolute;
            top: 90px;
        }
        /* The Close Button */

        .close {
            color: #aaaaaa;
            float: right;
            font-size: 28px;
            font-weight: bold;
        }

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

<h2>Modal Example</h2>

    <div><input id="myInputTextBox" /></div>

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

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

        <!-- Modal content -->
        <div class="modal-content">
            <span class="close">&times;</span>
            <p>Some text in the Modal..</p>
        </div>

    </div>

https://jsfiddle.net/6esv2vsy/