dropdown-toggle

bootstrap5.css

bootstrap5.css
.btn-primary:not(:disabled):not(.disabled):active,
.btn-primary:not(:disabled):not(.disabled).active,
.show > .btn-primary.dropdown-toggle {
  color: #fff;
  background-color: #0062cc;
  border-color: #005cbf;
}
bootstrap5.css
.btn-primary:not(:disabled):not(.disabled):active:focus,
.btn-primary:not(:disabled):not(.disabled).active:focus,
.show > .btn-primary.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(38, 143, 255, 0.5);
}
bootstrap5.css
.btn-secondary:not(:disabled):not(.disabled):active,
.btn-secondary:not(:disabled):not(.disabled).active,
.show > .btn-secondary.dropdown-toggle {
  color: #fff;
  background-color: #545b62;
  border-color: #4e555b;
}
bootstrap5.css
.btn-secondary:not(:disabled):not(.disabled):active:focus,
.btn-secondary:not(:disabled):not(.disabled).active:focus,
.show > .btn-secondary.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(130, 138, 145, 0.5);
}
bootstrap5.css
.btn-success:not(:disabled):not(.disabled):active,
.btn-success:not(:disabled):not(.disabled).active,
.show > .btn-success.dropdown-toggle {
  color: #fff;
  background-color: #1e7e34;
  border-color: #1c7430;
}
bootstrap5.css
.btn-success:not(:disabled):not(.disabled):active:focus,
.btn-success:not(:disabled):not(.disabled).active:focus,
.show > .btn-success.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(72, 180, 97, 0.5);
}
bootstrap5.css
.btn-info:not(:disabled):not(.disabled):active,
.btn-info:not(:disabled):not(.disabled).active,
.show > .btn-info.dropdown-toggle {
  color: #fff;
  background-color: #117a8b;
  border-color: #10707f;
}
bootstrap5.css
.btn-info:not(:disabled):not(.disabled):active:focus,
.btn-info:not(:disabled):not(.disabled).active:focus,
.show > .btn-info.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(58, 176, 195, 0.5);
}
bootstrap5.css
.btn-warning:not(:disabled):not(.disabled):active,
.btn-warning:not(:disabled):not(.disabled).active,
.show > .btn-warning.dropdown-toggle {
  color: #212529;
  background-color: #d39e00;
  border-color: #c69500;
}
bootstrap5.css
.btn-warning:not(:disabled):not(.disabled):active:focus,
.btn-warning:not(:disabled):not(.disabled).active:focus,
.show > .btn-warning.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(222, 170, 12, 0.5);
}
bootstrap5.css
.btn-danger:not(:disabled):not(.disabled):active,
.btn-danger:not(:disabled):not(.disabled).active,
.show > .btn-danger.dropdown-toggle {
  color: #fff;
  background-color: #bd2130;
  border-color: #b21f2d;
}
bootstrap5.css
.btn-danger:not(:disabled):not(.disabled):active:focus,
.btn-danger:not(:disabled):not(.disabled).active:focus,
.show > .btn-danger.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(225, 83, 97, 0.5);
}
bootstrap5.css
.btn-light:not(:disabled):not(.disabled):active,
.btn-light:not(:disabled):not(.disabled).active,
.show > .btn-light.dropdown-toggle {
  color: #212529;
  background-color: #dae0e5;
  border-color: #d3d9df;
}
bootstrap5.css
.btn-light:not(:disabled):not(.disabled):active:focus,
.btn-light:not(:disabled):not(.disabled).active:focus,
.show > .btn-light.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(216, 217, 219, 0.5);
}
bootstrap5.css
.btn-dark:not(:disabled):not(.disabled):active,
.btn-dark:not(:disabled):not(.disabled).active,
.show > .btn-dark.dropdown-toggle {
  color: #fff;
  background-color: #1d2124;
  border-color: #171a1d;
}
bootstrap5.css
.btn-dark:not(:disabled):not(.disabled):active:focus,
.btn-dark:not(:disabled):not(.disabled).active:focus,
.show > .btn-dark.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(82, 88, 93, 0.5);
}
bootstrap5.css
.btn-outline-primary:not(:disabled):not(.disabled):active,
.btn-outline-primary:not(:disabled):not(.disabled).active,
.show > .btn-outline-primary.dropdown-toggle {
  color: #fff;
  background-color: #007bff;
  border-color: #007bff;
}
bootstrap5.css
.btn-outline-primary:not(:disabled):not(.disabled):active:focus,
.btn-outline-primary:not(:disabled):not(.disabled).active:focus,
.show > .btn-outline-primary.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.5);
}
bootstrap5.css
.btn-outline-secondary:not(:disabled):not(.disabled):active,
.btn-outline-secondary:not(:disabled):not(.disabled).active,
.show > .btn-outline-secondary.dropdown-toggle {
  color: #fff;
  background-color: #6c757d;
  border-color: #6c757d;
}
bootstrap5.css
.btn-outline-secondary:not(:disabled):not(.disabled):active:focus,
.btn-outline-secondary:not(:disabled):not(.disabled).active:focus,
.show > .btn-outline-secondary.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(108, 117, 125, 0.5);
}
bootstrap5.css
.btn-outline-success:not(:disabled):not(.disabled):active,
.btn-outline-success:not(:disabled):not(.disabled).active,
.show > .btn-outline-success.dropdown-toggle {
  color: #fff;
  background-color: #28a745;
  border-color: #28a745;
}
bootstrap5.css
.btn-outline-success:not(:disabled):not(.disabled):active:focus,
.btn-outline-success:not(:disabled):not(.disabled).active:focus,
.show > .btn-outline-success.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(40, 167, 69, 0.5);
}
bootstrap5.css
.btn-outline-info:not(:disabled):not(.disabled):active,
.btn-outline-info:not(:disabled):not(.disabled).active,
.show > .btn-outline-info.dropdown-toggle {
  color: #fff;
  background-color: #17a2b8;
  border-color: #17a2b8;
}
bootstrap5.css
.btn-outline-info:not(:disabled):not(.disabled):active:focus,
.btn-outline-info:not(:disabled):not(.disabled).active:focus,
.show > .btn-outline-info.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(23, 162, 184, 0.5);
}
bootstrap5.css
.btn-outline-warning:not(:disabled):not(.disabled):active,
.btn-outline-warning:not(:disabled):not(.disabled).active,
.show > .btn-outline-warning.dropdown-toggle {
  color: #212529;
  background-color: #ffc107;
  border-color: #ffc107;
}
bootstrap5.css
.btn-outline-warning:not(:disabled):not(.disabled):active:focus,
.btn-outline-warning:not(:disabled):not(.disabled).active:focus,
.show > .btn-outline-warning.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(255, 193, 7, 0.5);
}
bootstrap5.css
.btn-outline-danger:not(:disabled):not(.disabled):active,
.btn-outline-danger:not(:disabled):not(.disabled).active,
.show > .btn-outline-danger.dropdown-toggle {
  color: #fff;
  background-color: #dc3545;
  border-color: #dc3545;
}
bootstrap5.css
.btn-outline-danger:not(:disabled):not(.disabled):active:focus,
.btn-outline-danger:not(:disabled):not(.disabled).active:focus,
.show > .btn-outline-danger.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(220, 53, 69, 0.5);
}
bootstrap5.css
.btn-outline-light:not(:disabled):not(.disabled):active,
.btn-outline-light:not(:disabled):not(.disabled).active,
.show > .btn-outline-light.dropdown-toggle {
  color: #212529;
  background-color: #f8f9fa;
  border-color: #f8f9fa;
}
bootstrap5.css
.btn-outline-light:not(:disabled):not(.disabled):active:focus,
.btn-outline-light:not(:disabled):not(.disabled).active:focus,
.show > .btn-outline-light.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(248, 249, 250, 0.5);
}
bootstrap5.css
.btn-outline-dark:not(:disabled):not(.disabled):active,
.btn-outline-dark:not(:disabled):not(.disabled).active,
.show > .btn-outline-dark.dropdown-toggle {
  color: #fff;
  background-color: #343a40;
  border-color: #343a40;
}
bootstrap5.css
.btn-outline-dark:not(:disabled):not(.disabled):active:focus,
.btn-outline-dark:not(:disabled):not(.disabled).active:focus,
.show > .btn-outline-dark.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.2rem rgba(52, 58, 64, 0.5);
}
bootstrap5.css
.dropdown-toggle {
  white-space: nowrap;
}
bootstrap5.css
.dropdown-toggle::after {
  display: inline-block;
  margin-left: 0.255em;
  vertical-align: 0.255em;
  content: "";
  border-top: 0.3em solid;
  border-right: 0.3em solid transparent;
  border-bottom: 0;
  border-left: 0.3em solid transparent;
}
bootstrap5.css
.dropdown-toggle:empty::after {
  margin-left: 0;
}
bootstrap5.css
.dropup .dropdown-toggle::after {
  display: inline-block;
  margin-left: 0.255em;
  vertical-align: 0.255em;
  content: "";
  border-top: 0;
  border-right: 0.3em solid transparent;
  border-bottom: 0.3em solid;
  border-left: 0.3em solid transparent;
}
bootstrap5.css
.dropup .dropdown-toggle:empty::after {
  margin-left: 0;
}
bootstrap5.css
.dropright .dropdown-toggle::after {
  display: inline-block;
  margin-left: 0.255em;
  vertical-align: 0.255em;
  content: "";
  border-top: 0.3em solid transparent;
  border-right: 0;
  border-bottom: 0.3em solid transparent;
  border-left: 0.3em solid;
}
bootstrap5.css
.dropright .dropdown-toggle:empty::after {
  margin-left: 0;
}
bootstrap5.css
.dropright .dropdown-toggle::after {
  vertical-align: 0;
}
bootstrap5.css
.dropleft .dropdown-toggle::after {
  display: inline-block;
  margin-left: 0.255em;
  vertical-align: 0.255em;
  content: "";
}
bootstrap5.css
.dropleft .dropdown-toggle::after {
  display: none;
}
bootstrap5.css
.dropleft .dropdown-toggle::before {
  display: inline-block;
  margin-right: 0.255em;
  vertical-align: 0.255em;
  content: "";
  border-top: 0.3em solid transparent;
  border-right: 0.3em solid;
  border-bottom: 0.3em solid transparent;
}
bootstrap5.css
.dropleft .dropdown-toggle:empty::after {
  margin-left: 0;
}
bootstrap5.css
.dropleft .dropdown-toggle::before {
  vertical-align: 0;
}
bootstrap5.css
.btn-group > .btn:not(:last-child):not(.dropdown-toggle),
.btn-group > .btn-group:not(:last-child) > .btn {
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}
bootstrap5.css
.dropdown-toggle-split {
  padding-right: 0.5625rem;
  padding-left: 0.5625rem;
}
bootstrap5.css
.dropdown-toggle-split::after,
.dropup .dropdown-toggle-split::after,
.dropright .dropdown-toggle-split::after {
  margin-left: 0;
}
bootstrap5.css
.dropleft .dropdown-toggle-split::before {
  margin-right: 0;
}
bootstrap5.css
.btn-sm + .dropdown-toggle-split,
.btn-group-sm > .btn + .dropdown-toggle-split {
  padding-right: 0.375rem;
  padding-left: 0.375rem;
}
bootstrap5.css
.btn-lg + .dropdown-toggle-split,
.btn-group-lg > .btn + .dropdown-toggle-split {
  padding-right: 0.75rem;
  padding-left: 0.75rem;
}
bootstrap5.css
.btn-group-vertical > .btn:not(:last-child):not(.dropdown-toggle),
.btn-group-vertical > .btn-group:not(:last-child) > .btn {
  border-bottom-right-radius: 0;
  border-bottom-left-radius: 0;
}
bootstrap5.css
.input-group > .input-group-prepend > .btn,
.input-group > .input-group-prepend > .input-group-text,
.input-group > .input-group-append:not(:last-child) > .btn,
.input-group > .input-group-append:not(:last-child) > .input-group-text,
.input-group > .input-group-append:last-child > .btn:not(:last-child):not(.dropdown-toggle),
.input-group > .input-group-append:last-child > .input-group-text:not(:last-child) {
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}

html bootstrap5 Sample

button要素を使用したドロップダウン:dropdownとdata-toggle


  <div class="dropdown">
    <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown"
      aria-haspopup="true" aria-expanded="false">
      ドロップダウン
    </button>
    <!-- ドロップダウンメニュー -->
    <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
      <a class="dropdown-item" href="#">メニュー01</a>
      <a class="dropdown-item" href="#">メニュー02</a>
      <a class="dropdown-item" href="#">メニュー03</a>
    </div>
  </div>

ボタングループに設定するドロップダウン:btn-group


  <!-- ボタングループにすると、ドロップダウンメニューのデザインが変わる -->
  <div class="btn-group">
    <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true"
      aria-expanded="false">
      ドロップダウン
    </button>
    <div class="dropdown-menu">
      <a class="dropdown-item" href="#">メニュー01</a>
      <a class="dropdown-item" href="#">メニュー02</a>
      <a class="dropdown-item" href="#">メニュー03</a>
    </div>
  </div>

メニュー項目にbuttonを使用する:dropdown-menu


  <div class="dropdown">
    <!-- 切り替えボタン -->
    <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown"
      aria-haspopup="true" aria-expanded="false">
      ドロップダウン
    </button>
    <!-- ドロップダウンメニュー -->
    <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
      <button class="dropdown-item" type="button">メニュー01</button>
      <button class="dropdown-item" type="button">メニュー02</button>
      <button class="dropdown-item" type="button">メニュー03</button>
    </div>
  </div>

メニューの位置をボタンと右寄せにする:dropdown-menu-right


  <div class="btn-group">
    <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true"
      aria-expanded="false">
      メニューの位置を右寄せにしたドロップダウン
    </button>
    <div class="dropdown-menu dropdown-menu-right">
      <button class="dropdown-item" type="button">メニュー01</button>
      <button class="dropdown-item" type="button">メニュー02</button>
      <button class="dropdown-item" type="button">メニュー03</button>
    </div>
  </div>

切り替えボタンにaタグ要素を使用したドロップダウン:dropdown-toggle


  <div class="dropdown">
    <!-- 切り替えボタン -->
    <a class="btn btn-secondary dropdown-toggle" href="#" role="button" id="dropdownMenuLink" data-toggle="dropdown"
      aria-haspopup="true" aria-expanded="false">
      ドロップダウン
    </a>
    <div class="dropdown-menu" aria-labelledby="dropdownMenuLink">
      <a class="dropdown-item" href="#">メニュー01</a>
      <a class="dropdown-item" href="#">メニュー02</a>
      <a class="dropdown-item" href="#">メニュー03</a>
    </div>
  </div>

メニュー項目にアクティブの状態を設定する:active


  <div class="btn-group">
    <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true"
      aria-expanded="false">ドロップダウン</button>
    <!-- ドロップダウンメニュー -->
    <div class="dropdown-menu">
      <a class="dropdown-item" href="#">メニュー01</a>
      <a class="dropdown-item disabled" href="#">メニュー02(無効)</a>
      <a class="dropdown-item active" href="#">メニュー03(アクティブ)</a>
    </div>
  </div>

左側表示のドロップメニュー:dropleft


  <div class="container py-5 d-flex justify-content-center">
    <!-- 左方向へのドロップ -->
    <div class="btn-group dropleft">
      <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true"
        aria-expanded="false">左方向へのドロップ</button>
      <div class="dropdown-menu" aria-labelledby="dropdownMenuLink">
        <a class="dropdown-item" href="#">メニュー01</a>
        <a class="dropdown-item" href="#">メニュー02</a>
        <a class="dropdown-item" href="#">メニュー03</a>
      </div>
    </div>
  </div>

右側表示のドロップメニュー:dropright


  <div class="container py-5 d-flex justify-content-center">
    <!-- 右方向へのドロップ -->
    <div class="btn-group dropright">
      <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true"
        aria-expanded="false">右方向へのドロップ</button>
      <div class="dropdown-menu" aria-labelledby="dropdownMenuLink">
        <a class="dropdown-item" href="#">メニュー01</a>
        <a class="dropdown-item" href="#">メニュー02</a>
        <a class="dropdown-item" href="#">メニュー03</a>
      </div>
    </div>
  </div>

上側表示のドロップメニュー:dropup


  <div class="container py-5 d-flex justify-content-center">
    <!-- 上方向へのドロップ -->
    <div class="btn-group dropup">
      <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true"
        aria-expanded="false">上方向へのドロップ</button>
      <div class="dropdown-menu" aria-labelledby="dropdownMenuLink">
        <a class="dropdown-item" href="#">メニュー01</a>
        <a class="dropdown-item" href="#">メニュー02</a>
        <a class="dropdown-item" href="#">メニュー03</a>
      </div>
    </div>
  </div>

オーバーフロー(枠から飛び出す)を制約する設定:data-boundary


  <div class="bg-info text-center" style="width:250px;height:250px;overflow:scroll;">
    <br><br><br>
    <div class="dropdown">
      <!-- ata-boundary="scrollParent"-->
      <button class="btn btn-secondary dropdown-toggle" data-toggle="dropdown"
        data-boundary="scrollParent">ドロップダウンボタン</button>
      <div class="dropdown-menu">
        <a href="#" class="dropdown-item">スクロールウィンドウ幅で制約されるドロップダウンメニュー</a>
        <a href="#" class="dropdown-item">スクロールウィンドウ幅で制約されるドロップダウンメニュー</a>
        <a href="#" class="dropdown-item">スクロールウィンドウ幅で制約されるドロップダウンメニュー</a>
      </div>
    </div>
  </div>

スペースがない場合に、反対側にドロップダウンを表示させる:data-flip







  <div class="box" style="overflow: auto">
    <br><br><br><br><br>
    <div class="dropdown">
      <!-- data-flip="true"-->
      <button class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" data-flip="true">ドロップダウンボタン</button>
      <div class="dropdown-menu">
        <a class="dropdown-item" href="#">メニュー1</a>
        <a class="dropdown-item" href="#">メニュー2</a>
        <a class="dropdown-item" href="#">メニュー3</a>
      </div>
    </div>
  </div>

ドロップダウンのオフセット値を設定する:data-offset


  <div class="dropdown">
    <button type="button" class="btn btn-secondary dropdown-toggle" id="dropdownMenuButton" data-toggle="dropdown"
      data-offset="10,20" aria-haspopup="true" aria-expanded="false">ドロップダウンボタン</button>
    <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
      <a class="dropdown-item" href="#">メニュー1</a>
      <a class="dropdown-item" href="#">メニュー2</a>
      <a class="dropdown-item" href="#">メニュー3</a>
    </div>
  </div>

ドロップダウンメニューにdivでテキストを配置する:text-muted


  <div class="dropdown">
    <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown"
      aria-haspopup="true" aria-expanded="false">ドロップダウン</button>
    <!-- ドロップダウンメニュー -->
    <div class="dropdown-menu p-3 text-muted" style="max-width: 300px;">
      <p>メニュー内のテキストその1</p>
      <p class="text-danger">メニュー内のテキストその2</p>
    </div>
  </div>

トグルボタンでdivコンテンツに様々な要素を追加する:dropdown-toggleとdropdown-menu


  <div class="btn-group">
    <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true"
      aria-expanded="false">ドロップダウン</button>
    <!-- divで作成するコンテンツありのメニュー -->
    <div class="dropdown-menu">
      <h6 class="dropdown-header">ドロップダウンメニューのタイトル</h6>
      <form class="px-4 py-3">
        <div class="form-group">
          <label for="email">メールアドレス</label>
          <input type="email" class="form-control" id="email" placeholder="email@example.com">
        </div>
        <div class="form-group">
          <label for="password">パスワード</label>
          <input type="password" class="form-control" id="password" placeholder="Password">
        </div>
        <div class="form-check">
          <input type="checkbox" class="form-check-input" id="check">
          <label class="form-check-label" for="check"> ログイン情報を記憶 </label>
        </div>
        <button type="submit" class="btn btn-secondary">ログイン</button>
      </form>
      <div class="dropdown-divider"></div>
      <a class="dropdown-item" href="#1">初めての方</a>
      <a class="dropdown-item" href="#2">パスワードをお忘れの方</a>
    </div>
  </div>

ドロップダウンにリンクなしの項目を追加する:dropdown-item-text


  <div class="dropdown">
    <button class="btn btn-secondary dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true"
      aria-expanded="false">ドロップダウン</button>
    <div class="dropdown-menu">
      <!-- メニューの説明分など入れたい場合に利用 -->
      <span class="dropdown-item-text">非リンクテキスト</span>
      <a class="dropdown-item" href="#1">メニュー1</a>
      <a class="dropdown-item" href="#2">メニュー2</a>
      <a class="dropdown-item" href="#3">メニュー3</a>
    </div>
  </div>

ドロップダウンで用意されているJSメソッド:dropdpown('toggle')


  <!-- ドロップダウン -->
  <div class="dropdown">
    <!-- 切り替えボタン -->
    <button class="btn btn-primary dropdown-toggle" type="button" id="dropdownExample" data-toggle="dropdown"
      aria-haspopup="true" aria-expanded="false">
      ドロップダウン
    </button>
    <!-- 最初から選択肢を出しておく -->
    <div class="dropdown-menu" aria-labelledby="dropdownExample">
      <a class="dropdown-item" href="#">メニュー01</a>
      <a class="dropdown-item" href="#">メニュー02</a>
      <a class="dropdown-item" href="#">メニュー03</a>
    </div>
  </div>
  <script>
    $(function () {
      $('#dropdownExample').dropdown('toggle');
    });
  </script>

ドロップダウンのオフセット値を設定する:offset


  <!-- data-offset="x,y" はメニューの表示位置を右方向に x、下方向に y ずれた位置に表示します。 -->
  <div class="dropdown">
    <button type="button" class="btn btn-secondary dropdown-toggle" id="dropdownMenuButton" data-toggle="dropdown"
      aria-haspopup="true" aria-expanded="false">ドロップダウンボタン</button>
    <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
      <a class="dropdown-item" href="#">メニュー1</a>
      <a class="dropdown-item" href="#">メニュー2</a>
      <a class="dropdown-item" href="#">メニュー3</a>
    </div>
  </div>
  <script>
    $(function () {
      $('#dropdownMenuButton').dropdown({
        offset: '10, 20'
      })
    });
  </script>

スプリットボタン(分割ボタン)のドロップダウン:dropdown-toggle-split


  <div class="btn-group">
    <button type="button" class="btn btn-secondary">スプリットボタン</button>
    <!-- ボタンとメニューを分割して表示する -->
    <button type="button" class="btn btn-secondary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown"
      aria-haspopup="true" aria-expanded="false">
    </button>
    <!-- ドロップダウンメニュー -->
    <div class="dropdown-menu">
      <a class="dropdown-item" href="#">メニュー01</a>
      <a class="dropdown-item" href="#">メニュー02</a>
      <a class="dropdown-item" href="#">メニュー03</a>
    </div>
  </div>

入力グループ ドロップダウン付きアドオン:input-group-append


  <div class="input-group">
    <input type="text" class="form-control" aria-label="ドロップダウン付テキスト入力欄">
    <div class="input-group-append">
      <button class="btn btn-secondary dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true"
        aria-expanded="false">アクション</button>
      <div class="dropdown-menu">
        <a class="dropdown-item" href="#">リンク1</a>
        <a class="dropdown-item" href="#">リンク2</a>
        <a class="dropdown-item" href="#">リンク3</a>
      </div>
    </div>
  </div>

入力グループ スプリットボタン付きアドオン:input-group-append


  <div class="input-group">
    <input type="text" class="form-control" aria-label="スプリットボタン付テキスト入力欄">
    <div class="input-group-append">
      <button type="button" class="btn btn-secondary">アクション</button>
      <button type="button" class="btn btn-secondary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown"
        aria-haspopup="true" aria-expanded="false">
        <span class="sr-only">ドロップダウン切替</span>
      </button>
      <div class="dropdown-menu">
        <a class="dropdown-item" href="#">リンク1</a>
        <a class="dropdown-item" href="#">リンク2</a>
        <a class="dropdown-item" href="#">リンク3</a>
      </div>
    </div>
  </div>

ドロップダウンメニュー:data-toggleとdropdown


  <!-- .dropdown, .dropdown-toggle, data-toggle="dropdown", .dropdown-menu, .dropdown-item を組み合わせてドロップダウンメニューを作成する -->
  <div class="btn-group" role="group" aria-label="ドロップダウンを含むボタングループ">
    <button type="button" class="btn btn-secondary">1</button>
    <div class="btn-group" role="group">
      <button id="dropmenu1" type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown"
        aria-haspopup="true" aria-expanded="false">
        ドロップダウン
      </button>
      <div class="dropdown-menu" aria-labelledby="dropmenu1">
        <a class="dropdown-item" href="#">リンク1</a>
        <a class="dropdown-item" href="#">リンク2</a>
      </div>
    </div>
  </div>

垂直方向ボタングループ:btn-group-vertical


  <div class="btn-group-vertical" role="group" aria-label="ドロップダウンを含むボタングループ">
    <button type="button" class="btn btn-secondary">上ボタン</button>
    <button type="button" class="btn btn-secondary">中ボタン</button>
    <div class="btn-group" role="group">
      <button id="drop2" type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown"
        aria-haspopup="true" aria-expanded="false">
        ドロップダウン
      </button>
      <div class="dropdown-menu" aria-labelledby="drop2">
        <a class="dropdown-item" href="#">リンク1</a>
        <a class="dropdown-item" href="#">リンク2</a>
      </div>
    </div>
    <button type="button" class="btn btn-secondary">下ボタン</button>
  </div>

ナビゲーションドロップダウンメニュー:dropdown-toggle


  <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <a class="navbar-brand" href="#">ブランド</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav"
      aria-controls="navbarNav" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav">
      <ul class="navbar-nav">
        <li class="nav-item dropdown">
          <!-- dropdown-toggleを使う -->
          <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenu" data-toggle="dropdown"
            aria-haspopup="true" aria-expanded="false">
            ドロップダウンメニュー
          </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdownMenu">
            <a class="dropdown-item" href="#">サブメニュー1</a>
            <a class="dropdown-item" href="#">サブメニュー2</a>
            <a class="dropdown-item" href="#">サブメニュー3</a>
          </div>
        </li>
        <li class="nav-item active"><a class="nav-link" href="#">メニュー1</a></li>
        <li class="nav-item active"><a class="nav-link" href="#">メニュー2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">メニュー3</a></li>
      </ul>
    </div>
  </nav>

ピル型ナビゲーションドロップダウン:nav-linkとdropdown-toggle


  <ul class="nav nav-pills">
    <li class="nav-item"><a class="nav-link active" href="#">アクティブ</a></li>
    <li class="nav-item dropdown">
      <a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button" aria-haspopup="true"
        aria-expanded="false">ドロップダウン</a>
      <div class="dropdown-menu">
        <a class="dropdown-item" href="#">リンク1</a>
        <a class="dropdown-item" href="#">リンク2</a>
        <a class="dropdown-item" href="#">リンク3</a>
        <div class="dropdown-divider"></div>
        <a class="dropdown-item" href="#">その他リンク</a>
      </div>
    </li>
    <li class="nav-item"><a class="nav-link" href="#">リンク</a></li>
    <li class="nav-item"><a class="nav-link disabled" href="#">無効</a></li>
  </ul>

タブ型ナビゲーションドロップダウン:dropdown-toggle


  <ul class="nav nav-tabs">
    <li class="nav-item"><a class="nav-link active" href="#">アクティブ</a></li>
    <li class="nav-item dropdown">
      <a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button" aria-haspopup="true"
        aria-expanded="false">ドロップダウン</a>
      <div class="dropdown-menu">
        <a class="dropdown-item" href="#">リンク1</a>
        <a class="dropdown-item" href="#">リンク2</a>
        <a class="dropdown-item" href="#">リンク3</a>
        <div class="dropdown-divider"></div>
        <a class="dropdown-item" href="#">その他リンク</a>
      </div>
    </li>
    <li class="nav-item"><a class="nav-link" href="#">リンク</a></li>
    <li class="nav-item"><a class="nav-link disabled" href="#">無効</a></li>
  </ul>