Dropdown trong Boostrap 4

Dropdown trong Boostrap 4

Dropdown cơ bản

Dropdown về cơ bản là một Component bao gồm một button và một menu, khi người dùng nhấn vào Button thì Menu sẽ xuất hiện cho phép người dùng lựa chọn một giá trị từ một danh sách có sẵn. Dưới đây là hình ảnh của một vài Dropdown:

Sử dụng .dropdown để tạo ra các Menu thả xuống, với các Menu dropdown-menu và Menu Item .dropdown-item

<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Dropdowns</h2> <p>The .dropdown class is used to indicate a dropdown menu.</p> <p>Use the .dropdown-menu class to actually build the dropdown menu.</p> <p>To open the dropdown menu, use a button or a link with a class of .dropdown-toggle and data-toggle="dropdown".</p> <div class="dropdown"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Dropdown button </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> <a class="dropdown-item" href="#">Link 3</a> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Giải thích ví dụ:

Lớp .dropdown biểu thị một menu thả xuống.

Để mở menu thả xuống, hãy sử dụng nút hoặc liên kết có lớp .dropdown-toggle và thuộc tính data-toggle = ‘dropdown’.

Thêm lớp .dropdown-menu vào phần tử div để thực sự tạo menu thả xuống. Sau đó, thêm lớp .dropdown-item vào từng phần tử (liên kết hoặc nút) bên trong menu thả xuống.

Phân tách Dropdown trong Boostrap

Lớp .dropdown-divider được sử dụng để phân tách các liên kết bên trong menu thả xuống bằng đường viền ngang mỏng:

<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Dropdowns</h2> <p>The .dropdown-divider class is used to separate links inside the dropdown menu with a thin horizontal line:</p> <div class="dropdown"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Dropdown button </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> <a class="dropdown-item" href="#">Link 3</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="#">Another link</a> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Tiêu đề Dropdown

Lớp .dropdown-header được sử dụng để thêm các tiêu đề bên trong menu thả xuống:

<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Dropdowns</h2> <p>The .dropdown-header class is used to add headers inside the dropdown menu:</p> <div class="dropdown"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Dropdown button </button> <div class="dropdown-menu"> <h5 class="dropdown-header">Dropdown header</h5> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> <a class="dropdown-item" href="#">Link 3</a> <h5 class="dropdown-header">Dropdown header</h5> <a class="dropdown-item" href="#">Another link</a> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Mục vô hiệu hoá và hoạt động

Đánh dấu một mục thả xuống cụ thể với lớp .active (thêm màu nền xanh lam).

Để vô hiệu hoá một mục trong menu thả xuống, hãy sử dụng lớp .disabled (có màu văn bản xám nhạt và biểu tượng ‘biển báo cấm đỗ xe’ khi di chuột):

<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Dropdowns</h2> <p>The .active class adds a blue background color to the active link.</p> <p>The .disabled class disables a dropdown item (grey text color and a no-parking-sign on hover).</p> <div class="dropdown"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Dropdown button </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Normal</a> <a class="dropdown-item active" href="#">Active</a> <a class="dropdown-item disabled" href="#">Disabled</a> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Vị trí Dropdown

Bạn cũng có thể tạo menu ‘dropright’ hoặc ‘dropleft’ bằng cách thêm lớp .dropright hoặc .dropleft vào phần tử thả xuống. Lưu ý rằng dấu mũ/mũi tên được thêm tự động:

<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Dropdowns</h2> <p>Add the .dropdown-menu-right class to .dropdown-menu to right-align the dropdown menu.</p> <div class="dropdown"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Wide dropdown button to demonstrate this example </button> <div class="dropdown-menu dropdown-menu-right"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> <a class="dropdown-item" href="#">Link 3</a> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Dropup

Nếu bạn muốn menu thả xuống mở rộng lên trên thay vì xuống dưới, hãy thay đổi phần tử div với class = ‘dropdown’ thành ‘dropup’:

<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <br> <div class="container"> <h2>Dropdowns</h2> <p>The .dropup class makes the dropdown menu expand upwards instead of downwards:</p> <div class="dropup"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Dropup button </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Văn bản Dropdown

Lớp .dropdown-item-text được sử dụng để thêm văn bản thuần túy vào một mục thả xuống hoặc được sử dụng trên các liên kết để tạo kiểu liên kết mặc định.

<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Dropdowns</h2> <p>The .dropdown-item-text class is used to add plain text to a dropdown, or used on links for default link styling.</p> <div class="dropdown"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Dropdown button </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> <a class="dropdown-item-text" href="#">Text Link</a> <span class="dropdown-item-text">Just Text</span> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Nhóm các nút Dropdown

<!DOCTYPE html> <html lang="en"> <head> <title>Bootstrap Example</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Nesting Button Groups</h2> <p>Nest button groups to create dropdown menus:</p> <div class="btn-group"> <button type="button" class="btn btn-primary">Apple</button> <button type="button" class="btn btn-primary">Samsung</button> <div class="btn-group"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Sony </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Tablet</a> <a class="dropdown-item" href="#">Smartphone</a> </div> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Nút Split Dropdown

<!DOCTYPE html> <html lang="en"> <head> <title>Bootstrap Example</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Dropdown Split Buttons</h2> <div class="btn-group"> <button type="button" class="btn btn-primary">Primary</button> <button type="button" class="btn btn-primary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown"> </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> </div> </div> <div class="btn-group"> <button type="button" class="btn btn-secondary">Secondary</button> <button type="button" class="btn btn-secondary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown"> </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> </div> </div> <div class="btn-group"> <button type="button" class="btn btn-success">Success</button> <button type="button" class="btn btn-success dropdown-toggle dropdown-toggle-split" data-toggle="dropdown"> </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> </div> </div> <div class="btn-group"> <button type="button" class="btn btn-info">Info</button> <button type="button" class="btn btn-info dropdown-toggle dropdown-toggle-split" data-toggle="dropdown"> </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> </div> </div> <div class="btn-group"> <button type="button" class="btn btn-warning">Warning</button> <button type="button" class="btn btn-warning dropdown-toggle dropdown-toggle-split" data-toggle="dropdown"> </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> </div> </div> <div class="btn-group"> <button type="button" class="btn btn-danger">Danger</button> <button type="button" class="btn btn-danger dropdown-toggle dropdown-toggle-split" data-toggle="dropdown"> </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Link 1</a> <a class="dropdown-item" href="#">Link 2</a> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Nhóm nút dọc Dropdown

<!DOCTYPE html> <html lang="en"> <head> <title>Bootstrap Example</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <h2>Vertical Button Group with Dropdown</h2> <div class="btn-group-vertical"> <button type="button" class="btn btn-primary">Apple</button> <button type="button" class="btn btn-primary">Samsung</button> <div class="btn-group"> <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown"> Sony </button> <div class="dropdown-menu"> <a class="dropdown-item" href="#">Tablet</a> <a class="dropdown-item" href="#">Smartphone</a> </div> </div> </div> </div> </body> </html>
Code language:HTML, XML(xml)

Kết luận

Bài viết đã chỉ ra cho bạn cách sử dụng Dropdown trong Boostrap 4 thông qua các ví dụ. Mời bạn tiếp tục theo dõi bài tiếp theo.

Các bạn có thể tham khảo các bài viết hay về Bootstrap tại đây.


Hãy tham gia nhóm Học lập trình để thảo luận thêm về các vấn đề cùng quan tâm.

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