HTML
CSS
JavaScript
HTML
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<head>
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<title>输入长度判断插件Bootstrap MaxLength - 光年(Light Year Admin)后台管理系统模板</title>
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<body>
<div class="container-fluid">
  
  <div class="row">
    <div class="col-md-12">
      <div class="card">
        <div class="card-header"><h4>输入长度判断插件 Bootstrap MaxLength</h4></div>
        <div class="card-body">
          
          <div class="form-group">
            <label for="defaultconfig">默认</label>
            <p class="text-muted">默认当剩余字符小于等于10时,提示将显示:</p>
            <input type="text" class="form-control" maxlength="25" name="defaultconfig" id="defaultconfig">
          </div>
          <div class="form-group">
            <label for="thresholdconfig">阈值</label>
            <p class="text-muted">使用<code>threshold</code>选项表示还有多少字符可以开始显示指示。</p>
            <input type="text" maxlength="25" name="thresholdconfig" class="form-control" id="thresholdconfig">
          </div>
          <div class="form-group">
            <label for="placement">位置</label>
            <p class="text-muted">您所需要做的就是用其中一个字符串指定<code>placement</code>选项。如果未指定,则将被定位到“底部”。</p>
            <input type="text" class="form-control" maxlength="25" name="placement" id="placement">
          </div>
          <div class="form-group">
            <label for="alloptions">始终显示</label>
            <p class="text-muted mb-3 font-13">如果<code>alwaysShow</code>为true,则将忽略阈值,其余长度指示将始终在输入或获取焦点时显示。默认值:false。</p>
            <input type="text" class="form-control" maxlength="25" name="alloptions" id="alloptions">
          </div>
          <div class="form-group">
            <label for="mb-2">文本域</label>
            <p class="textarea">Bootstrap maxlength 支持文本区域和输入。即使在旧的IE上。</p>
            <textarea id="textarea" class="form-control" maxlength="225" rows="3" placeholder="此文本区域限制为225个字符。"></textarea>
          </div>
          
        </div>
      </div>
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</body>
</html>
CSS
.bootstrap-maxlength {
    padding-top: .2em;
    line-height: 1.5;
    border-radius: 0px;
}
JavaScript
$(document).ready(function(){
    // 默认使用
    $("input#defaultconfig").maxlength({
        warningClass: "label label-info",
        limitReachedClass: "label label-warning"
    });
    // 设置阈值
    $("input#thresholdconfig").maxlength({
        threshold: 20,
        warningClass: "label label-info",
        limitReachedClass: "label label-warning"
    });
    // 设置提示显示的位置
    $("input#placement").maxlength({
        // 可使用的值有: bottom, left, top, right, bottom-right, top-right, top-left, bottom-left 和 centered-right。
        // 你也可以使用 : bottom-right-inside, top-right-inside, top-left-inside and bottom-left-inside.
        alwaysShow: true,
        placement: "bottom-right-inside",
        warningClass: "label label-info",
        limitReachedClass: "label label-warning"
    })
    // 始终显示
    $("input#alloptions").maxlength({
        alwaysShow: true,
        warningClass: "label label-success",
        limitReachedClass: "label label-danger",
        separator: " 个字符; ",
        preText: "已输入 ",
        postText: " 个可用字符。",
        validate: !0
    });
    // 文本域使用
    $("textarea#textarea").maxlength({
        threshold: 255,
        warningClass: "label label-info",
        limitReachedClass: "label label-warning"
    });
});