1

你能告诉我我的代码有什么问题吗？

Widget _createProfileStepper() {
int currentStep = 0;

List<Step> createAccSteps = [
  new Step(
    title: Container(),
    content: new Text('This is the first step.'),
    isActive: currentStep >= 0,
    state: currentStep >= 0 ? StepState.editing : StepState.disabled,
  ),
  new Step(
    title: Container(),
    content: new Text('This is the second step.'),
    isActive: currentStep >= 0,
    state: currentStep >= 1 ? StepState.editing : StepState.disabled,
  ),
  new Step(
    title: Container(),
    content: new Text('This is the third step.'),
    isActive: currentStep >= 0,
    state: currentStep >= 2 ? StepState.editing : StepState.disabled,
  ),
  new Step(
    title: Container(),
    content: new Text('This is the second step.'),
    isActive: currentStep >= 0,
    state: currentStep >= 3 ? StepState.editing : StepState.disabled,
  ),
  new Step(
    title: Container(),
    content: new Text('This is the third step.'),
    isActive: currentStep >= 0,
    state: currentStep >= 4 ? StepState.editing : StepState.disabled,
  ),
];

return Scaffold(
  appBar: AppBar(
    title: Text("Create Profile"),
  ),
  body: Stepper(
    type: StepperType.horizontal,
    currentStep: currentStep,
    onStepTapped: (step) {
      setState(() {
        currentStep = step;
      });
    },
    onStepContinue: () {
      setState(() {
        if (currentStep < createAccSteps.length - 1) {
          currentStep = currentStep + 1;
        } else {}
      });
    },
    onStepCancel: () {
      setState(() {
        if(currentStep > 0){
          currentStep = currentStep - 1;
        }
        else {
          currentStep = 0;
        }
      });
    },
    steps: createAccSteps,
  ),
);
}

我遵循了 Flutter 步进器的所有示例，但仍然没有运气。我可以点击继续按钮，但它没有移动到另一个步骤。我是不是忘记了什么？我创建了一个有状态的 Widget 类，然后一个按钮会带我调用这个 _createProfileStepper()。谢谢。

4

2 回答 2

2

因此您无法从内部列表中访问您的 currentStep 以进行启动。

“isActive”也应该是一个布尔值（并且只影响样式https://docs.flutter.io/flutter/material/Step/isActive.html）

此外，将空的 Container() 作为标题似乎有点奇怪，您可以将其删除或将步骤号放在那里

尝试将您的步骤更改为

Step(
    title: Text("Step One"),
    content: new Text("This is the first step."),
    isActive: true
),
于 2018-10-16T09:36:54.023 回答
1

_createProfileStepper()即使在有状态的小部件中使用它，小部件中的整个代码也会变得无状态。这是因为每当build有状态小部件的方法重新运行时，它都会调用_createProfileStepper()这将导致整个步进器小部件重新初始化，即重新创建步进器，因此继续不起作用。

为什么不单独为步骤创建一个有状态小部件并使用该小部件而不是您从中获取的小部件_createProfileStepper()。例如：

class _SimpleWidgetState extends State<SimpleWidget> {
  int currentStep = 0;

  List<Step> steps = [
    Step(
        title: Text("Step One"),
        content: Text("This is the first step"),
        isActive: true
    ),
    Step(
      title: Text("Step Two"),
      content: Text("This is the second step"),
      isActive: true,
    ),
    Step(
      title: Text("Step Three"),
      content: Text("This is the third step"),
      isActive: true,
    ),
    Step(
      title: Text("Step Four"),
      content: Text("This is the fourth step"),
      isActive: false,
    ),
  ];

  @override
  Widget build(BuildContext context) {
    return Container(
      child: Stepper(
        steps: steps,
        currentStep: currentStep,
        type: StepperType.vertical,
        onStepTapped: (step) {
          setState(() {
            currentStep = step;
            print(step);
          });
        },
        onStepCancel: () {
          setState(() {
            currentStep > 0 ? currentStep -= 1 : currentStep = 0;
          });
        },
        onStepContinue: () {
          setState(() {
            currentStep < steps.length - 1 ? currentStep += 1 : currentStep = 0;
          });
        },
      ),
    );
  }
}

class SimpleWidget extends StatefulWidget {
  @override
  _SimpleWidgetState createState() {
    // TODO: implement createState
    return _SimpleWidgetState();
  }
}

然后SimpleWidget()在你想用的地方使用_createProfileStepper()

其次 ，关于您的列表访问 currentStep 的问题是因为只有static成员可以用于初始化

于 2018-10-17T01:23:26.247 回答