Flutter：如何手动为构建器设置索引？

Question

我目前只能在此处设置索引。我尝试了各种设置索引的方法，但是不能更改索引的值。此方法来自软件包：

https://pub.dev/packages/flutter_tindercard

由于我正在构建卡，因此可能需要返回索引以正确地与返回卡的后退按钮同步。但是即使我在构建器中执行减量运算符，构建器的索引也只会不断增加。这是构建器的代码：

  Widget _cardBuild() {
    return TinderSwapCard(
      orientation: AmassOrientation.BOTTOM,
      totalNum: articleList.length != null ? articleList.length + backCount : 0,
      stackNum: 3,
      swipeEdge: 1.0,
      animDuration: 50,
      maxWidth: MediaQuery.of(context).size.width * 0.9,
      maxHeight: 410.1,
      minWidth: MediaQuery.of(context).size.width * 0.8,
      minHeight: 410,
      cardBuilder: (context, index) {
        return Card(
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(10.0),
          ),
          child: Conditional.single(
            context: context,
            conditionBuilder: (BuildContext context) => pendingBack > 0,
            widgetBuilder: (BuildContext context) {
              return _generateCards(cardIndex);
            },
            fallbackBuilder: (BuildContext context) {
              return _generateCards(index);
            },
          ),
        );
      },
      cardController: controller = CardController(),
      swipeUpdateCallback: (DragUpdateDetails details, Alignment align) {
        /// Get swiping card's alignment
        if (align.x < 0) {
          //Card is LEFT swiping
        } else if (align.x > 0) {
          //Card is RIGHT swiping
        }
      },
      swipeCompleteCallback: (CardSwipeOrientation orientation, int index) {
        if (index == articleList.length) {
          setState(() {
            isOutOfCards = true;
          });
        } else {
          setState(() {
            cardIndex++;
          });
        }
      },
    );
  }

该应用程序的示例屏幕截图： [