html中的

required  hidden  readonly disabled

这些属性,动态启用禁用

<
  div 
  class=
  "form-group" [
  hidden]=
  "model.isPersistent"
  >
 
<
  label
  for=
  "idletimeout"
  >IdleTimeOut
  </
  label
  >
 
<
  input
  type=
  "text"
  class=
  "form-control"
  id=
  "idletimeout" [(
  ngModel)]=
  "model.idleTimeout" [
  required]=
  "!model.isPersistent"
  name=
  "idleTimeout"
  value=
  '60' #
  idletimeout=
  "ngModel"
  >
 
<
  div [
  hidden]=
  "idletimeout.valid || idletimeout.pristine"
  class=
  "alert alert-danger"
  >
 

  IdleTimeOut is required
 
 
</
  div
  >
 
</
  div
  >
 
<
  button
  type=
  "submit"
  class=
  "btn btn-success" [
  disabled]=
  "!addEditWorkStationForm.form.valid"
  >Submit
  </
  button
  >

就拿这段代码为例,原本的hidden加上[]就能实现了。 

原理不多说,先会用再说啦