在按钮单击 angular2 上应用样式

Question

我的 HTML 如下，

    <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" (click) aria-haspopup="true" aria-expanded="false"><span class="flag">
    </span>Spain <span class="caret"></span></button>
    <ul  class="dropdown-menu dropdown-menu-right">

点击上面的按钮我想应用下面的样式，

.dropdown-menu
{
display :block;
}

Answer 1

基本上在按钮单击时放置一个 ng 类并设置变量值。

<button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" (click)="toggle = !toggle" aria-haspopup="true" aria-expanded="false">
    <span class="flag"></span> Spain <span class="caret"></span>
</button>
      <ul  class="dropdown-menu dropdown-menu-right" [ngClass]="{'blockStyle': toggle == true>

.blockStyle{
display :block;
  }