输入组 - Input Groups
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