ReactCSSTransitionGroup不起作用

Question

我在父组件中有以下代码 - 默认情况下，Module1将显示并单击，它将被module2取代 - 有这个逻辑，尝试在module2切换时添加一些基本的淡入/淡出，但转换不会发生..我在这里缺少什么？ ？

<ReactCSSTransitionGroup transitionName="example" transitionEnterTimeout={500} transitionLeaveTimeout={300}>
          <div className="container" onClick={this.onClick.bind(this)}>
            <span>
              <a> link
              </a>
            </span>
            {this.state.showModule ? <Module2 /> : <Module1 />}
          </div>
          </ReactCSSTransitionGroup>

.example-enter {
  opacity: 0.01;
  transition: opacity .5s ease-in;
}

.example-enter.example-enter-active {
  opacity: 1;
}

.example-leave {
  opacity: 1;
  transition: opacity .5s ease-in;
}

.example-leave.example-leave-active {
  opacity: 0.01;
}

.example-appear {
  opacity: 0.05;
  transition: opacity .5s ease-in;
}

.example-appear.example-appear-active {
  opacity: 1;
}