具有警告类可让您设置输入警告。
您可以尝试运行以下代码来实现has-warning类：
<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <link href = "/bootstrap/css/bootstrap.min.css" rel = "stylesheet"> <script src = "/scripts/jquery.min.js"></script> <script src = "/bootstrap/js/bootstrap.min.js"></script> </head> <body> <form class = "form-horizontal" role = "form"> <div class = "form-group has-warning"> <label class = "col-sm-2 control-label" for = "inputWarning"> Input with warning </label> <div class = "col-sm-10"> <input type = "text" class = "form-control" id = "inputWarning"> </div> </div> </form> </body> </html>