如何在背景打开/关闭颤动期间更改 AppBar 文本答案

【问题标题】：How to change AppBar text during backdrop open/close flutter如何在背景打开/关闭颤动期间更改 AppBar 文本
【发布时间】：2019-05-10 17:09:59
【问题描述】：

我在我的应用中实现了背景。我想在背景打开/关闭期间更改 AppBar 文本。我尝试在 IconButton onPressed 工作期间使用 Boolean isOpen 使其为真/假，但我想知道哪种方法是完美的。是否有任何 api 来检测背景打开/关闭？

    import 'package:expense_manager_app/widget/navigation_panel.dart';
import 'package:flutter/material.dart';

class BackDropPage extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _BackDropState();
  }
}

class _BackDropState extends State<BackDropPage>
    with SingleTickerProviderStateMixin {
  AnimationController controller;
  var mTitle = "Home";
  var mIsOpen = false;

  @override
  void initState() {
    super.initState();
    controller = AnimationController(
        vsync: this, duration: Duration(milliseconds: 100), value: 1.0);
  }

  @override
  void dispose() {
    super.dispose();
    controller.dispose();
  }

  bool get isPanelVisible {
    final AnimationStatus status = controller.status;
    return status == AnimationStatus.completed ||
        status == AnimationStatus.forward;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('$mTitle'),
        elevation: 0.0,
        leading: new IconButton(
          onPressed: () {
            controller.fling(velocity: isPanelVisible ? -1.0 : 1.0);
            setState(() {
              if (mIsOpen) {
                mIsOpen = false;
                mTitle = "Home";
              } else {
                mTitle = "Menu";
                mIsOpen = true;
              }
            });
          },
          icon: new AnimatedIcon(
            icon: AnimatedIcons.close_menu,
            progress: controller.view,
          ),
        ),
      ),
      body: NavigationPanelPage(controller: controller),
    );
  }
}

【问题讨论】：

请附上您用于背景的代码。
@rmtmckenzie 我更新了代码

标签： flutter flutter-layout appbar flutter-animation

【解决方案1】：

最后我用 isPanelVisible bool 完成了自己。

appBar: AppBar(
    title: Text('$mTitle'),
    elevation: 0.0,
    leading: new IconButton(
      onPressed: () {
        controller.fling(velocity: isPanelVisible ? -1.0 : 1.0);
        setState(() {
          if (isPanelVisible) {
            mTitle = "Home";
          } else {
            mTitle = "Menu";
          }
        });
      },
      icon: new AnimatedIcon(
        icon: AnimatedIcons.close_menu,
        progress: controller.view,
      ),
    ),
  ),

【讨论】：