Select2 从输入字段而不是下拉菜单开始

Question

我使用js库select2。这是我现在拥有的屏幕截图：
开始：

点击下拉菜单：

现在是否可以从一个输入字段开始，而不是直接使用下拉列表？我知道这是可能的，因为您可以在 select2 网站上找到它。一个例子是这样的：

但是文档非常简短。这就是我现在拥有的：

<input type="text" name="questions[question1]" id="question1" class="question1" style="width:500px"/>

function createQuestionTags(data, question_number){
  $(".question" + question_number).select2({
    createSearchChoice: function (term, data) {
      if ($(data).filter(function () {
        return this.text.localeCompare(term) === 0;
      }).length === 0) {
        return {
          id: term,
          text: term
        };
      }
    },
    data: data,
    placeholder: "Enter Question",
    allowClear:true
  });
}

（数据是从ajax调用接收的）

Answer 1

在该示例中，您看到的实际上是一个多选或多值下拉框。它不是像您在代码中使用的那样的单个值下拉框。根据 Select2 网站，select2 将检测到您正在尝试使用多选框，并将自动应用该样式而不是默认样式（下拉箭头等）。

如果您实际上需要一个单值下拉框，则没有直接的方法可以使其以多选的格式显示，使其看起来像常规输入框。可能有一种方法可以通过添加或删除 CSS 类来伪造它。我玩了一会但没找到。

由于您不需要格式、搜索框或多选功能（我假设），因此您可能不需要使用 select2 库。

更新：看来您不是第一个尝试这样做的人。他们计划添加此功能，但可能需要一段时间： https://github.com/select2/select2/issues/1345

Answer 2

我能想到的唯一解决方法是在设置时同时使用

multiple: true

和

maximumSelectionSize: 1

。

请在此处查看我的示例：http://jsfiddle.net/DanEtchy/Lnf8j/

Answer 3

这在 Select2 4.0.0 中可以通过新的选择适配器实现。您可以将

SingleSelection

替换为

MultipleSelection

（包括任何相关的装饰器），它应该按预期运行。

$.fn.select2.amd.require([
  'select2/selection/multiple',
  'select2/selection/search',
  'select2/dropdown',
  'select2/dropdown/attachBody',
  'select2/dropdown/closeOnSelect',
  'select2/compat/containerCss',
  'select2/utils'
], function (MultipleSelection, Search, Dropdown, AttachBody, CloseOnSelect, ContainerCss, Utils) {
  var SelectionAdapter = Utils.Decorate(
    MultipleSelection,
    Search
  );
  
  var DropdownAdapter = Utils.Decorate(
    Utils.Decorate(
      Dropdown,
      CloseOnSelect
    ),
    AttachBody
  );
  
  $('.inline-search').select2({
    dropdownAdapter: DropdownAdapter,
    selectionAdapter: SelectionAdapter
  });
  
  $('.dropdown-search').select2({
    selectionAdapter: MultipleSelection
  });
  
  $('.autocomplete').select2({
    dropdownAdapter: DropdownAdapter,
    selectionAdapter: Utils.Decorate(SelectionAdapter, ContainerCss),
    containerCssClass: 'select2-autocomplete'
  });
});

.select2-selection__choice__remove {
  display: none !important;
}

.select2-container--focus .select2-autocomplete .select2-selection__choice {
  display: none;
}

<link href="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/css/select2.css" rel="stylesheet"/>

<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/js/select2.full.js"></script>

<p>With an inline search box</p>

<select style="width: 200px" class="inline-search">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>

<p>With the search box in the dropdown</p>

<select style="width: 200px" class="dropdown-search">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>

<p>With the selection hidden when it is focused</p>

<select style="width: 200px" class="autocomplete">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>

默认情况下，Select2 将设置下拉列表以进行搜索（而不是选择容器），如果您想完美模拟多选，则需要覆盖该搜索。

Answer 4

而不是

Select2

，更好的选择是

selectize

，因为

Select2

看起来死了

使用很简单：

$('select').selectize(options);

这里是如何使用和自定义的示例数量

selectize

Answer 5

就我而言，我希望用户从下拉列表中进行的选择显示在下拉列表下方的列表中，而不是像常规下拉列表一样工作。所以这个解决方法对我有用：

$('#myselect').select2({
    multiple:true
})
.on('select2:select', function (e) {
    //clear the input box after a selection is made
    $(this).val([]).trigger('change');
});

当然，如果您希望所选项目在 select2 的输入框中保持选中状态，就像使用常规 select2 多选列表一样，那么这是行不通的。

Answer 6

使用 Bootstrap 样式自定义实现，简单但实用：

var elements = $(document).find('select.form-control');
for (var i = 0, l = elements.length; i < l; i++) {
  var $select = $(elements[i]), $label = $select.parents('.form-group').find('label');
  
  $select.select2({
    allowClear: false,
    placeholder: $select.data('placeholder'),
    minimumResultsForSearch: 0,
    theme: 'bootstrap',
		width: '100%' // https://github.com/select2/select2/issues/3278
  });
  
  // Trigger focus
  $label.on('click', function (e) {
    $(this).parents('.form-group').find('select').trigger('focus').select2('focus');
  });
  
  // Trigger search
  $select.on('keydown', function (e) {
    var $select = $(this), $select2 = $select.data('select2'), $container = $select2.$container;
    
    // Unprintable keys
    if (typeof e.which === 'undefined' || $.inArray(e.which, [0, 8, 9, 12, 16, 17, 18, 19, 20, 27, 33, 34, 35, 36, 37, 38, 39, 44, 45, 46, 91, 92, 93, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 123, 124, 144, 145, 224, 225, 57392, 63289]) >= 0) {
      return true;
    }

    // Already opened
    if ($container.hasClass('select2-container--open')) {
      return true;
    }

    $select.select2('open');

    // Default search value
    var $search = $select2.dropdown.$search || $select2.selection.$search, query = $.inArray(e.which, [13, 40, 108]) < 0 ? String.fromCharCode(e.which) : '';
    if (query !== '') {
      $search.val(query).trigger('keyup');
    }
  });

  // Format, placeholder
  $select.on('select2:open', function (e) {
		var $select = $(this), $select2 = $select.data('select2'), $dropdown = $select2.dropdown.$dropdown || $select2.selection.$dropdown, $search = $select2.dropdown.$search || $select2.selection.$search, data = $select.select2('data');
    
    // Above dropdown
    if ($dropdown.hasClass('select2-dropdown--above')) {
      $dropdown.append($search.parents('.select2-search--dropdown').detach());
    }

    // Placeholder
    $search.attr('placeholder', (data[0].text !== '' ? data[0].text : $select.data('placeholder')));
  });
}

/* !important not needed with less */

.form-group {
  padding: 25px;
}

.form-group.above {
  position: absolute;
  bottom: 0; left: 0; right: 0;
}

.select2-container--open .select2-selection {
    box-shadow: none!important;
}

.select2-container--open .select2-selection .select2-selection__arrow {
    z-index: 9999; /* example */
}

.select2-dropdown {
  /* .box-shadow(@form-control-focus-box-shadow); (from select2-boostrap */
  -webkit-box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(102, 175, 233, 0.6);
  box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(102, 175, 233, 0.6);
  
  /* border-color: @input-border-focus; */
  border-color: #66afe9;
  border-top-width: 1px!important;
  border-top-style: solid!important;
  /* border-top-left-radius: @input-border-radius; */
  border-top-left-radius: 4px!important;
  /* border-top-right-radius: @input-border-radius; */
  border-top-right-radius: 4px!important;
  
  /* margin-top: -@input-height-base; */
  margin-top: -34px!important;
}

.select2-dropdown .select2-search {
    padding: 0;
}

.select2-dropdown .select2-search .select2-search__field {
  
  /* !important not needed using less */
  border-top: 0!important;
  border-left: 0!important;
  border-right: 0!important;
  border-radius: 0!important;
  
  /* padding: @padding-base-vertical @padding-base-horizontal; */
  padding: 6px 12px;
  
  /* height: calc(@input-height-base - 1px); */
  height: 33px;
}

.select2-dropdown.select2-dropdown--above {
  /* border-bottom: 1px solid @input-border-focus; */
  border-bottom: 1px solid #66afe9!important;
  /* border-bottom-left-radius: @input-border-radius; */
  border-bottom-left-radius: 4px!important;
  /* border-bottom-right-radius: @input-border-radius; */
  border-bottom-right-radius: 4px!important;
  /* margin-top: @input-height-base; */
  margin-top: 34px!important;
}

.select2-dropdown.select2-dropdown--above .select2-search .select2-search__field {
  /* border-top: 1px solid @input-border; */
  border-top: 1px solid #66afe9!important;
  border-bottom: 0!important;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet"/>
<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.1/css/select2.min.css" rel="stylesheet"/>
<link href="https://select2.github.io/select2-bootstrap-theme/css/select2-bootstrap.css" rel="stylesheet"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.1/js/select2.full.min.js"></script>
<div class="form-group">
  <label class="control-label">Below example (click label to focus)</label>
  <select class="form-control" id="select2-single-box" name="select2-single-box" data-placeholder="Pick your choice" data-tabindex="1">
    <option></option>
    <option value="1">First choice</option>
    <option value="2">Second choice</option>
    <option value="3">Third choice</option>
    <option value="4">Fourth choice</option>
    <option value="5">Fifth choice</option>
    <option value="6">Sixth choice</option>
    <option value="7">Seventh choice</option>
    <option value="8">Eighth choice</option>
    <option value="9">Ninth choice</option>
  </select>
</div>
<div class="form-group above">
  <label class="control-label">Above example (click label to focus)</label>
  <select class="form-control" id="select2-single-box" name="select2-single-box" data-placeholder="Pick your choice" data-tabindex="2">
    <option></option>
    <option value="1">First choice</option>
    <option value="2">Second choice</option>
    <option value="3">Third choice</option>
    <option value="4">Fourth choice</option>
    <option value="5">Fifth choice</option>
    <option value="6">Sixth choice</option>
    <option value="7">Seventh choice</option>
    <option value="8">Eighth choice</option>
    <option value="9">Ninth choice</option>
  </select>
</div>

Select2 的

minimumInputLength: 1

选项可以隐藏焦点/打开时的下拉菜单...

更新：代码清理，不要在焦点上打开下拉菜单。

Answer 7

使用这些属性

$('#placeSelect').select2({
width: '100%',
allowClear: true,
multiple: true,
maximumSelectionSize: 1,   
});

只需在下拉菜单的 onchange 事件上调用此函数

function ResentForMe(){
var _text=$('.select2-selection__rendered li:first-child').attr('title');
$('.select2-selection__rendered li:first-child').remove();
$('.select2-search__field').val(_text);
$('.select2-search__field').css('width','100%');
}

注意：从选择中删除“多个”属性

Answer 8

伙计们，在任何地方添加一些CSS：

.select2-dropdown--below {
    margin-top: -33px !important;
    border-radius: 4px !important;
}

试试吧！ ;)

Answer 9

马特，）

这个作品

 $('.search-town-flat').select2({
        多重：真实，
        占位符：“输入值”，
        允许清除：真，
        最大选择长度：2，
        主题：“经典”
    }).on('select2:select', 函数 (e) {
        $(this).val([]).trigger('更改');
        $(this).val([e.params.data.id]).trigger("更改");
    });

Answer 10

$.fn.select2.amd.require([
  'select2/selection/multiple',
  'select2/selection/search',
  'select2/dropdown',
  'select2/dropdown/attachBody',
  'select2/dropdown/closeOnSelect',
  'select2/compat/containerCss',
  'select2/utils'
], function (MultipleSelection, Search, Dropdown, AttachBody, CloseOnSelect, ContainerCss, Utils) {
  var SelectionAdapter = Utils.Decorate(
    MultipleSelection,
    Search
  );
  
  var DropdownAdapter = Utils.Decorate(
    Utils.Decorate(
      Dropdown,
      CloseOnSelect
    ),
    AttachBody
  );
  
  $('.inline-search').select2({
    dropdownAdapter: DropdownAdapter,
    selectionAdapter: SelectionAdapter
  });
  
  $('.dropdown-search').select2({
    selectionAdapter: MultipleSelection
  });
  
  $('.autocomplete').select2({
    dropdownAdapter: DropdownAdapter,
    selectionAdapter: Utils.Decorate(SelectionAdapter, ContainerCss),
    containerCssClass: 'select2-autocomplete'
  });
});

.select2-selection__choice__remove {
  display: none !important;
}

.select2-container--focus .select2-autocomplete .select2-selection__choice {
  display: none;
}

<link href="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/css/select2.css" rel="stylesheet"/>

<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/js/select2.full.js"></script>

<p>With an inline search box</p>

<select style="width: 200px" class="inline-search">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>

<p>With the search box in the dropdown</p>

<select style="width: 200px" class="dropdown-search">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>

<p>With the selection hidden when it is focused</p>

<select style="width: 200px" class="autocomplete">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>

Answer 11

我只是用 CSS 格式化了一个标准输入框，使其看起来像 Select2() 下拉列表：

input {
    width: 100%;
    padding: 7px 5px;
    margin: 1px 0;
    display: inline-block;
    border: 1px solid #ccc;
    border-radius: 4px;
    box-sizing: border-box;
}

Answer 12

$.fn.select2.amd.require([
  'select2/selection/multiple',
  'select2/selection/search',
  'select2/dropdown',
  'select2/dropdown/attachBody',
  'select2/dropdown/closeOnSelect',
  'select2/compat/containerCss',
  'select2/utils'
], function (MultipleSelection, Search, Dropdown, AttachBody, CloseOnSelect, ContainerCss, Utils) {
  var SelectionAdapter = Utils.Decorate(
    MultipleSelection,
    Search
  );
  
  var DropdownAdapter = Utils.Decorate(
    Utils.Decorate(
      Dropdown,
      CloseOnSelect
    ),
    AttachBody
  );
  
  $('.inline-search').select2({
    dropdownAdapter: DropdownAdapter,
    selectionAdapter: SelectionAdapter
  });
  
  $('.dropdown-search').select2({
    selectionAdapter: MultipleSelection
  });
  
  $('.autocomplete').select2({
    dropdownAdapter: DropdownAdapter,
    selectionAdapter: Utils.Decorate(SelectionAdapter, ContainerCss),
    containerCssClass: 'select2-autocomplete'
  });
});

.select2-selection__choice__remove {
  display: none !important;
}

.select2-container--focus .select2-autocomplete .select2-selection__choice {
  display: none;
}

<link href="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/css/select2.css" rel="stylesheet"/>

<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/js/select2.full.js"></script>

<p>With an inline search box</p>

<select style="width: 200px" class="inline-search">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>

<p>With the search box in the dropdown</p>

<select style="width: 200px" class="dropdown-search">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>

<p>With the selection hidden when it is focused</p>

<select style="width: 200px" class="autocomplete">
  <option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option><option value="AL">Alabama</option>
  <option value="AK">Alaska</option>
  <option value="AZ">Arizona</option>
</select>