颤振错误 "PageController.page cannot be accessed before a PageView is built with it."

Question

在 PageViewBuilder 中，我想在 pub.dev 上找到的 ArgonTimerButton 上使用 onTap 移动到下一页，而不是滑动手势。我创建了一个控制器并使用了 controller.nextPage() 但它给了我这个错误：

'positions.isNotEmpty': PageController.page cannot be accessed before a PageView is built with it.

我的代码：

 final controller = PageController();
   @override
   Widget build(BuildContext context) {
   MediaQueryData size = MediaQuery.of(context).size;
   return  PageView.builder(
      physics: NeverScrollableScrollPhysics(),
      controller: PageController(),
      itemCount: widget.workoutExcercises.length,
      itemBuilder: (context, index) {
        return 

              //other widgets

              ArgonTimerButton(
                initialTimer: 3, // Optional
                height: 50,
                width: size.width * 0.55,
                minWidth: width * 0.40,
                color: Colors.white,
                borderRadius: 5.0,
                curve: Curves.easeInToLinear,
                child: Text(
                  "Done?",
                  style: TextStyle(
                      color: Colors.black,
                      fontSize: 24,
                      fontWeight: FontWeight.w700),
                ),
                loader: (timeLeft) {
                  return Text(
                    "Rest Time | $timeLeft",
                    style: TextStyle(
                        color: Colors.black,
                        fontSize: 18,
                        fontWeight: FontWeight.w700),
                  );
                },
                onTap: (startTimer, btnState) {
                  if (btnState == ButtonState.Idle) {
                    controller.nextPage(duration: Duration(milliseconds:1000), curve: Curves.easeInToLinear);
                  }
                },
              ),
            ],
          ),
        );
      },
    );

我该如何解决？

Answer 1

您正在创建控制器但并未使用它。

而不是：

controller: PageController(),

做：

controller: controller,

颤振错误 "PageController.page cannot be accessed before a PageView is built with it."

Flutter Error "PageController.page cannot be accessed before a PageView is built with it."

android

dart-pub

flutter