滾動條上的多選下拉列表位於頂部

Question

我有一個位置固定爲側欄的div。內側有幾個多選下拉菜單。問題是，當我打開任何下拉菜單並滾動側欄時，下拉菜單保持在屏幕內。

問題：

$('.jqms').multiselect();

@charset "UTF-8"; 
 
.header { 
 
    height: 500px; 
 
    overflow: scroll; 
 
} 
 

 
html { 
 
    background-color: #fcfcfc; 
 
} 
 

 
body { 
 
    padding: 1.5em; 
 
    margin: 2em auto; 
 
    max-width: 500px; 
 
    border: 1px solid #ccc; 
 
    background-color: #fff; 
 
} 
 

 
a { 
 
    transition: color .3s; 
 
    color: blue; 
 
} 
 
a:hover { 
 
    text-decoration: none; 
 
} 
 

 
h1 { 
 
    margin: 0 0 2rem; 
 
    text-align: center; 
 
} 
 
h1 a { 
 
    color: #000; 
 
    text-decoration: none; 
 
} 
 
h1 a:hover { 
 
    color: blue; 
 
    text-decoration: underline; 
 
} 
 

 
section { 
 
    display: flex; 
 
    flex-wrap: nowrap; 
 
    align-items: flex-start; 
 
} 
 
section > label { 
 
    display: inline-block; 
 
    width: 100px; 
 
} 
 
section + section { 
 
    margin-top: 1rem; 
 
} 
 
section.spacer  { 
 
    border-top: 1px dotted #ccc; 
 
    padding-top: 1rem; 
 
} 
 

 
footer { 
 
    border-top: 1px dashed #ccc; 
 
    margin-top: 2rem; 
 
    padding-top: .75rem; 
 
    font-size: .75rem; 
 
    text-align: center; 
 
} 
 
footer ul { 
 
    list-style: none; 
 
    padding: 0; 
 
    margin: 0; 
 
} 
 
footer li { 
 
    display: inline-block; 
 
} 
 
footer li + li { 
 
    margin-left: .5em; 
 
} 
 

 
.btn { 
 
    margin-left: .5em; 
 
} 
 

 
/* ---------------------------------------- * 
 
* multiselect        * 
 
* ---------------------------------------- */ 
 
.ui-multiselect--filter, .ui-multiselect--bulk { 
 
    padding: 5px 10px; 
 
    border-bottom: 1px solid #ccc; 
 
} 
 

 
.ui-multiselect--option, .ui-multiselect--optgroup-wrap label { 
 
    display: block; 
 
    padding: 3px 10px; 
 
} 
 

 
.ui-multiselect--display { 
 
    position: relative; 
 
    padding-right: 1.4em; 
 
    border: 1px solid #ccc; 
 
    border-radius: 0; 
 
    font-size: 1em; 
 
    cursor: pointer; 
 
    background-color: #fff; 
 
    text-align: left; 
 
} 
 
.ui-multiselect--display:focus { 
 
    outline: none; 
 
} 
 
.ui-multiselect--display:hover { 
 
    background-color: #ddd; 
 
} 
 
.ui-multiselect--icon { 
 
    transform: translateY(-50%); 
 
    display: block; 
 
    position: absolute; 
 
    right: .25em; 
 
    top: 50%; 
 
} 
 
.ui-multiselect--icon:after { 
 
    display: block; 
 
    border: .375em solid transparent; 
 
    border-top-color: #000; 
 
    border-bottom-width: 0; 
 
    content: ''; 
 
} 
 
.ui-multiselect--list-wrap { 
 
    position: absolute; 
 
    z-index: 100; 
 
    display: none; 
 
    margin-top: -1px; 
 
    border: 1px solid #ccc; 
 
    background-color: #fff; 
 
} 
 
.ui-multiselect--list { 
 
    margin: 0; 
 
    padding: 0; 
 
    list-style-type: none; 
 
} 
 
.ui-multiselect--list [type="checkbox"] { 
 
    position: relative; 
 
    top: -2px; 
 
    margin: 0 5px 0 0; 
 
    cursor: pointer; 
 
} 
 
.ui-multiselect--option { 
 
    cursor: pointer; 
 
} 
 
.ui-multiselect--option span { 
 
    white-space: nowrap; 
 
} 
 
.ui-multiselect--option:hover { 
 
    background-color: #ddd; 
 
} 
 
.ui-multiselect--optgroup-wrap label { 
 
    font-weight: bold; 
 
} 
 
.ui-multiselect--is-multiple .ui-multiselect--optgroup-wrap label { 
 
    cursor: pointer; 
 
} 
 
.ui-multiselect--optgroup-wrap.ui-multiselect--disabled label { 
 
    cursor: not-allowed; 
 
} 
 
.ui-multiselect--optgroup-wrap ul { 
 
    padding-left: 0; 
 
} 
 
.ui-multiselect--optgroup-wrap li { 
 
    padding-left: 20px; 
 
} 
 
.ui-multiselect--optgroup-wrap:hover { 
 
    background-color: #f7f7f7; 
 
} 
 
.ui-multiselect--optgroup-wrap + .ui-multiselect--optgroup-wrap { 
 
    border-top: 1px dotted #ccc; 
 
} 
 
.ui-multiselect--selected { 
 
    background-color: #efefef; 
 
} 
 
.ui-multiselect--disabled { 
 
    opacity: .5; 
 
    cursor: not-allowed; 
 
} 
 
.ui-multiselect--disabled [type="checkbox"] { 
 
    cursor: inherit; 
 
} 
 
.ui-multiselect--disabled:hover { 
 
    background-color: transparent; 
 
} 
 
.ui-multiselect--disabled .ui-multiselect--disabled { 
 
    opacity: 1; 
 
} 
 
.ui-multiselect--filter { 
 
    white-space: nowrap; 
 
} 
 
.ui-multiselect--filter label, 
 
.ui-multiselect--filter input, 
 
.ui-multiselect--filter button { 
 
    display: inline-block; 
 
} 
 
.ui-multiselect--filter label:after { 
 
    content: ':'; 
 
} 
 
.ui-multiselect--filter input { 
 
    margin: 0 5px; 
 
    padding: 0; 
 
    width: 80px; 
 
} 
 
.ui-multiselect--filter input:focus { 
 
    outline: none; 
 
} 
 
.ui-multiselect--filter button { 
 
    width: 22px; 
 
    height: 22px; 
 
    border-width: 0; 
 
    text-indent: -9999em; 
 
    white-space: nowrap; 
 
    border-radius: 0; 
 
    cursor: pointer; 
 
} 
 
.ui-multiselect--filter button:before { 
 
    float: left; 
 
    text-indent: 0; 
 
    content: 'X'; 
 
} 
 
.ui-multiselect--filter button:focus { 
 
    outline: none; 
 
} 
 
.ui-multiselect--bulk button + button { 
 
    margin-left: 5px; 
 
} 
 

 
.styling .ui-multiselect--display { 
 
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.2); 
 
    border-radius: 3px; 
 
    font-size: 1em; 
 
} 
 
.styling .ui-multiselect--display:hover { 
 
    box-shadow: 0 1px 5px 0 lightgreen; 
 
    background-color: #e8fce8; 
 
    border-color: lightgreen; 
 
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
 
<script src="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.11.2/jquery-ui.min.js"></script> 
 
<script src="//rawgit.com/dirkpeter/jquery-ui.multiselect.widget/dev/src/jquery-ui.multiselect.widget.js"></script> 
 

 

 
<div class="header"> 
 
<section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section> 
 
    
 
    <section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section> 
 
    <section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section> 
 
    <section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section> 
 
    <section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section> 
 
    <section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section><section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section><section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section> 
 
    <section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section> 
 
    <section> 
 
    <label for="select-1">Single</label> 
 
    <select id="select-1" class="jqms"> 
 
    <option value="1">Commodo Ridiculus</option> 
 
    <option value="2" selected>Vehicula Euismod</option> 
 
    <option value="3">Ipsum Dapibus</option> 
 
    <option value="4">Mollis Tellus</option> 
 
    <option value="5">Nibh Quam</option> 
 
    </select> 
 
</section> 
 
    
 
    
 
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</div>

https://codepen.io/shahil/pen/gGoJVX

更新：滾動DIV：只有當下拉被放置在溢出內部出現此問題。

Answer 1

問題與.header div overflow:scroll它有它自己的偏移量和位置。並且下拉選項元素<div class="ui-multiselect--list-wrap">直接位於<body>標籤下。因此，滾動正文時，下拉選項會移動。滾動.header div <body> psoition保持不變，這就是下拉選項保持在同一位置的原因。

我能想到的一個解決方案是在.header元素內移動下拉選項元素<div class="ui-multiselect--list-wrap">。當滾動.header時，下拉選項將響應滾動。

這裏的演示：（CSS與我修復搞砸您可能需要適當調整。）

https://codepen.io/anon/pen/zEpVyN