角度5-找不到管道“键值”

Question

错误错误：未捕获（承诺）：错误：模板解析错误： 找不到管道'keyvalue'（“

                 {{optionsData}}  <span  *ngFor="let [ERROR ->]item of postDetail.poll.votes | keyvalue">rgeeehr</span>

                </div"): ng:///NewPostModule/CommentComponent.html@87:57

错误：模板解析错误： 找不到管道'keyvalue'（“

                 {{optionsData}}  <span  *ngFor="let [ERROR ->]item of postDetail.poll.votes | keyvalue">rgeeehr</span>

                </div"): ng:///NewPostModule/CommentComponent.html@87:57