搜索/过滤器下拉列表在任何地方关闭

Question

我从W3School获得了此下拉，但仅当您再次单击按钮时，下拉菜单才关闭。如何通过单击搜索和下拉以外的任何位置来关闭它。

/* When the user clicks on the button,
toggle between hiding and showing the dropdown content */
function myFunction() {
    document.getElementById("myDropdown").classList.toggle("show");
}
function filterFunction() {
    var input, filter, ul, li, a, i;
    input = document.getElementById("myInput");
    filter = input.value.toUpperCase();
    div = document.getElementById("myDropdown");
    a = div.getElementsByTagName("a");
    for (i = 0; i < a.length; i++) {
        if (a[i].innerHTML.toUpperCase().indexOf(filter) > -1) {
            a[i].style.display = "";
        } else {
            a[i].style.display = "none";
        }
    }
}

.dropbtn {
    background-color: #4CAF50;
    color: white;
    padding: 16px;
    font-size: 16px;
    border: none;
    cursor: pointer;
}
.dropbtn:hover, .dropbtn:focus {
    background-color: #3e8e41;
}
#myInput {
    border-box: box-sizing;
    background-image: url('searchicon.png');
    background-position: 14px 12px;
    background-repeat: no-repeat;
    font-size: 16px;
    padding: 14px 20px 12px 45px;
    border: none;
    border-bottom: 1px solid #ddd;
}
#myInput:focus {outline: 3px solid #ddd;}
.dropdown {
    position: relative;
    display: inline-block;
}
.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f6f6f6;
    min-width: 230px;
    overflow: auto;
    border: 1px solid #ddd;
    z-index: 1;
}
.dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}
.dropdown a:hover {background-color: #ddd}
.show {display:block;}

<h2>Search/Filter Dropdown</h2>
<p>Click on the button to open the dropdown menu, and use the input field to search for a specific dropdown link.</p>
<div class="dropdown">
<button onclick="myFunction()" class="dropbtn">Dropdown</button>
  <div id="myDropdown" class="dropdown-content">
    <input type="text" placeholder="Search.." id="myInput" onkeyup="filterFunction()">
    <a href="#about">About</a>
    <a href="#base">Base</a>
    <a href="#blog">Blog</a>
    <a href="#contact">Contact</a>
    <a href="#custom">Custom</a>
    <a href="#support">Support</a>
    <a href="#tools">Tools</a>
  </div>
</div>

我从W3School获得了此下拉，但是仅当您再次单击按钮时，下拉菜单才关闭。如何通过单击搜索和下拉以外的任何位置来关闭它。

Answer 1

将事件侦听器添加到删除"表演"类的身体中。您可能想确保目标不是按钮或输入...

document.body.addEventListener("click", function(e){
  if(!e.target.classList.contains("dropbtn") && e.target.id != "myInput")  document.getElementById("myDropdown").classList.remove("show");
});

document.body.addEventListener("click", function(e){
  if(!e.target.classList.contains("dropbtn") && e.target.id != "myInput")  document.getElementById("myDropdown").classList.remove("show");
});
/* When the user clicks on the button,
toggle between hiding and showing the dropdown content */
function myFunction() {
    document.getElementById("myDropdown").classList.toggle("show");
}
function filterFunction() {
    var input, filter, ul, li, a, i;
    input = document.getElementById("myInput");
    filter = input.value.toUpperCase();
    div = document.getElementById("myDropdown");
    a = div.getElementsByTagName("a");
    for (i = 0; i < a.length; i++) {
        if (a[i].innerHTML.toUpperCase().indexOf(filter) > -1) {
            a[i].style.display = "";
        } else {
            a[i].style.display = "none";
        }
    }
}

.dropbtn {
    background-color: #4CAF50;
    color: white;
    padding: 16px;
    font-size: 16px;
    border: none;
    cursor: pointer;
}
.dropbtn:hover, .dropbtn:focus {
    background-color: #3e8e41;
}
#myInput {
    border-box: box-sizing;
    background-image: url('searchicon.png');
    background-position: 14px 12px;
    background-repeat: no-repeat;
    font-size: 16px;
    padding: 14px 20px 12px 45px;
    border: none;
    border-bottom: 1px solid #ddd;
}
#myInput:focus {outline: 3px solid #ddd;}
.dropdown {
    position: relative;
    display: inline-block;
}
.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f6f6f6;
    min-width: 230px;
    overflow: auto;
    border: 1px solid #ddd;
    z-index: 1;
}
.dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}
.dropdown a:hover {background-color: #ddd}
.show {display:block;}

<h2>Search/Filter Dropdown</h2>
<p>Click on the button to open the dropdown menu, and use the input field to search for a specific dropdown link.</p>
<div class="dropdown">
<button onclick="myFunction()" class="dropbtn">Dropdown</button>
  <div id="myDropdown" class="dropdown-content">
    <input type="text" placeholder="Search.." id="myInput" onkeyup="filterFunction()">
    <a href="#about">About</a>
    <a href="#base">Base</a>
    <a href="#blog">Blog</a>
    <a href="#contact">Contact</a>
    <a href="#custom">Custom</a>
    <a href="#support">Support</a>
    <a href="#tools">Tools</a>
  </div>
</div>