在输入框前后添加扩展

要将输入框和扩展包裹在同一个 .input-group 内部，扩展需要添加 .input-group-addon 样式

<form>
    <div class="row">
        <div class="col-xs-4">
            <div class="input-group">
                <span class="input-group-addon"><span class="glyphicon glyphicon-user"></span></span>
                <input type="text" class="form-control" placeholder="Username">
            </div>
        </div>
        <div class="col-xs-4">
            <div class="input-group">
                <input type="text" class="form-control" placeholder="Amount">
                <span class="input-group-addon">.00</span>
            </div>
        </div>
        <div class="col-xs-4">
            <div class="input-group">
                <span class="input-group-addon">$</span>
                <input type="text" class="form-control" placeholder="US Dollar">
                <span class="input-group-addon">.00</span>
            </div>
        </div>
    </div>
</form>

为检查框添加扩展

在 .input-group 内部，扩展需要添加 .input-group-addon 样式

<form>
    <div class="row">
        <div class="col-xs-6">
            <div class="input-group">
                <span class="input-group-addon">
                    <input type="checkbox">
                </span>
                <input type="text" class="form-control">
            </div>
        </div>

        <div class="col-xs-6">
            <div class="input-group">
                <span class="input-group-addon">
                    <input type="radio">
                </span>
                <input type="text" class="form-control">
            </div>
        </div>
    </div>
</form>

为输入框添加扩展按钮

包裹在 .input-group 内部，把按钮用 .input-group-btn 样式包裹起来

<form>
    <div class="row">
        <div class="col-xs-6">
            <div class="input-group">
                <input type="text" class="form-control" placeholder="Search…">
                <span class="input-group-btn">
                    <button type="button" class="btn btn-default">Go</button>
                </span>
            </div>
        </div>
        <div class="col-xs-6">
            <div class="input-group">
                <span class="input-group-btn">
                    <button type="button" class="btn btn-default">Action</button>
                    <button type="button" class="btn btn-default">Options</button>
                </span>
                <input type="text" class="form-control"  placeholder="Type something…">
            </div>
        </div>
    </div>
</form>

为输入框扩展下拉菜单

同样包裹在 .input-group 内部，把按钮用 .input-group-btn 样式包裹起来

<form>
    <div class="row">

        <div class="col-xs-6">
            <div class="input-group">
                <div class="input-group-btn">
                    <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">Action <span class="caret"></span></button>
                    <ul class="dropdown-menu">
                        <li><a href="#">Action</a></li>
                        <li><a href="#">Another action</a></li>
                        <li class="divider"></li>
                        <li><a href="#">Separated link</a></li>
                    </ul>
                </div>
                <input type="text" class="form-control">
            </div>
        </div>
        <div class="col-xs-6">
            <div class="input-group">
                <input type="text" class="form-control">
                <div class="input-group-btn">
                    <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">Action <span class="caret"></span></button>
                    <ul class="dropdown-menu pull-right">
                        <li><a href="#">Action</a></li>
                        <li><a href="#">Another action</a></li>
                        <li class="divider"></li>
                        <li><a href="#">Separated link</a></li>
                    </ul>
                </div>
            </div>
        </div>
    </div>
</form>

为输入框同时扩展按钮和下拉菜单

同样包裹在 .input-group 内部，把按钮用 .input-group-btn 样式包裹起来

<form>
    <div class="row">
        <div class="col-xs-6">
            <div class="input-group">
                <div class="input-group-btn">
                    <button tabindex="-1" class="btn btn-default" type="button">Action</button>
                    <button tabindex="-1" data-toggle="dropdown" class="btn btn-default dropdown-toggle" type="button">
                        <span class="caret"></span>
                        <span class="sr-only">Toggle Dropdown</span>
                    </button>
                    <ul class="dropdown-menu">
                        <li><a href="#">Action</a></li>
                        <li><a href="#">Another action</a></li>
                        <li class="divider"></li>
                        <li><a href="#">Separated link</a></li>
                    </ul>
                </div>
                <input type="text" class="form-control">
            </div>
        </div>

        <div class="col-xs-6">
            <div class="input-group">
                <input type="text" class="form-control">
                <div class="input-group-btn">
                    <button tabindex="-1" class="btn btn-default" type="button">Action</button>
                    <button tabindex="-1" data-toggle="dropdown" class="btn btn-default dropdown-toggle" type="button">
                        <span class="caret"></span>
                        <span class="sr-only">Toggle Dropdown</span>
                    </button>
                    <ul class="dropdown-menu pull-right">
                        <li><a href="#">Action</a></li>
                        <li><a href="#">Another action</a></li>
                        <li class="divider"></li>
                        <li><a href="#">Separated link</a></li>
                    </ul>
                </div>
            </div>
        </div>
    </div>
</form>

为输入组设置不同的尺寸

同样包裹在 .input-group 内部，同时设置 .input-group-lg .input-group-sm 之类的样式

<form>
    <!-- 大尺寸 -->
    <div class="row">
        <div class="col-xs-4">
            <div class="input-group input-group-lg">
                <span class="input-group-addon"><span class="glyphicon glyphicon-user"></span></span>
                <input type="text" class="form-control">
            </div>
        </div>
        <div class="col-xs-4">
            <div class="input-group input-group-lg">
                <span class="input-group-addon">
                    <input type="checkbox">
                </span>
                <input type="text" class="form-control">
            </div>
        </div>
        <div class="col-xs-4">
            <div class="input-group input-group-lg">
                <div class="input-group-btn">
                    <button tabindex="-1" class="btn btn-default" type="button">Action</button>
                    <button tabindex="-1" data-toggle="dropdown" class="btn btn-default dropdown-toggle" type="button">
                        <span class="caret"></span>
                        <span class="sr-only">Toggle Dropdown</span>
                    </button>
                    <ul class="dropdown-menu"> 
                        <li><a href="#">Action</a></li>
                        <li><a href="#">Another action</a></li>
                        <li class="divider"></li>
                        <li><a href="#">Separated link</a></li>
                    </ul>
                </div>
                <input type="text" class="form-control">
            </div>
        </div>
    </div>
</form>