如何为md-radio-button设置活动类？

Question

如何从Angular Material设置元素md-radio-button的活动类？

Answer 1

https://plnkr.co/edit/oL53j2Zqku3BkVVMzhNe?p=preview

<md-radio-group>
  <md-radio-button value="1">Option 1</md-radio-button>
  <md-radio-button #rb [class.custom-class]="rb.checked" value="2">Option 2</md-radio-button>
</md-radio-group>