javascript - Angular 为 2 的三态复选框

Question

我想做一个具有三种状态的输入框:选中、未选中和划线(又名失败)目前，我能够相应地进行检查/取消检查和更改计算

 <input type="checkbox" [ngStyle]="{content: expression}" *ngIf="milestone?.description" [checked]="milestone?.status == 'checked'" (change)="checkMilestone(milestone,initiative, $event, '')">

但是，我在添加 crossed (X) 复选框时遇到了问题。有谁知道应该怎么做？我是否应该这样说:

states = [
    { id: 0, status: 'checked'},
    { id: 1, status: 'unchecked'},
    { id: 2, status: 'crossed'}
];

并添加样式并相应地更改它们？我不确定如何添加三种样式而不是两种。

Answer 1

indeterminate复选框的状态可以用 property binding 设置.这是标记的简化版本，显示了 indeterminate 状态绑定(bind):

<input type="checkbox" [indeterminate]="milestone?.status === 'crossed'" 
  [ngModel]="milestone?.status === 'checked'" (ngModelChange)="checkMilestone(milestone)">

checkMilestone 方法可能是这样的:

checkMilestone(milestone) {
  switch (milestone.status) {
    case "checked": {
      milestone.status = "unchecked";
      break;
    }
    case "unchecked": {
      milestone.status = "crossed";
      break;
    }
    case "crossed": {
      milestone.status = "checked";
      break;
    }
  }
}

参见 this stackblitz用于演示。