This chapter will discuss about how to add dropdown menu to buttons using Bootstrap classes. To add a dropdown to a button, simply wrap the button and dropdown menu in a .btn-group. You can also use <span class = "caret"></span> to act as an indicator that the button is a dropdown.
The following example demonstrates a basic single button dropdowns −
<div class = "btn-group"> <button type = "button" class = "btn btn-default dropdown-toggle" data-toggle = "dropdown"> Default <span class = "caret"></span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div> <div class = "btn-group"> <button type = "button" class = "btn btn-primary dropdown-toggle" data-toggle = "dropdown"> Primary <span class = "caret"></span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div>
Split button dropdowns use the same general style as the dropdown button but add a primary action along with the dropdown. Split buttons have the primary action on the left and a toggle on the right that displays the dropdown.
<div class = "btn-group"> <button type = "button" class = "btn btn-default">Default</button> <button type = "button" class = "btn btn-default dropdown-toggle" data-toggle = "dropdown"> <span class = "caret"></span> <span class = "sr-only">Toggle Dropdown</span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div> <div class = "btn-group"> <button type = "button" class = "btn btn-primary">Primary</button> <button type = "button" class = "btn btn-primary dropdown-toggle" data-toggle = "dropdown"> <span class = "caret"></span> <span class = "sr-only">Toggle Dropdown</span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div>
You can use the dropdowns with any button size − .btn-large, .btn-sm, or .btn-xs.
<div class = "btn-group"> <button type = "button" class = "btn btn-default dropdown-toggle btn-lg" data-toggle = "dropdown"> Default <span class = "caret"></span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div> <div class = "btn-group"> <button type = "button" class = "btn btn-primary dropdown-toggle btn-sm" data-toggle = "dropdown"> Primary <span class = "caret"></span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div> <div class = "btn-group"> <button type = "button" class = "btn btn-success dropdown-toggle btn-xs" data-toggle = "dropdown"> Success <span class = "caret"></span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div>
Menus can also be built to drop up rather than down. To achieve this, simply add .dropup to the parent .btn-group container.
<div class = "row" style = "margin-left:50px; margin-top:200px"> <div class = "btn-group dropup"> <button type = "button" class = "btn btn-default dropdown-toggle" data-toggle = "dropdown"> Default <span class = "caret"></span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div> <div class = "btn-group dropup"> <button type = "button" class = "btn btn-primary dropdown-toggle" data-toggle = "dropdown"> Primary <span class = "caret"></span> </button> <ul class = "dropdown-menu" role = "menu"> <li><a href = "#">Action</a></li> <li><a href = "#">Another action</a></li> <li><a href = "#">Something else here</a></li> <li class = "divider"></li> <li><a href = "#">Separated link</a></li> </ul> </div> </div>