flutter 振颤容器未在丝攻上更换

bprjcwpo 于 2023-02-13 发布在 Flutter

关注(0)|答案(4)|浏览(80)

我尝试创建一个容器，它带有一个手势检测器，可以在onTap上改变颜色，但由于某种原因，它没有这样做。我有一个bool和一个函数来设置状态并改变它，在容器的backgroundColor中，我让它根据bool的颜色来改变。任何建议都将非常感谢。

import 'package:flutter/material.dart';

class VotingButton extends StatefulWidget {
  @override
  State<VotingButton> createState() => _VotingButtonState();
}

class _VotingButtonState extends State<VotingButton> {
  bool savePressed = false;

  void buttonPressed() {
    setState(() {
      if (savePressed == false) {
        savePressed == true;
      } else if (savePressed == true) {
        savePressed == false;
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(top: 18.0),
      child: GestureDetector(
        onTap: () {
          buttonPressed;
          print(savePressed); //stays false for some reason
        },
        child: Container(
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(6),
            color: savePressed ? Colors.blue : Colors.red[400],
          ),
          child: Padding(
            padding: const EdgeInsets.symmetric(vertical: 8.0, horizontal: 40),
            child: Text(
              'I\'ll be Here!',
              style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
            ),
          ),
        ),
      ),
    );
  }
}

flutter

来源：https://stackoverflow.com/questions/75397684/flutter-container-not-changing-on-tap

4条答案

按热度按时间

h5qlskok1#

import 'package:flutter/material.dart';

class VotingButton extends StatefulWidget {
  @override
  State<VotingButton> createState() => _VotingButtonState();
}

class _VotingButtonState extends State<VotingButton> {
  bool savePressed = false;

  void buttonPressed() {
    setState(() {
      if (savePressed == false) {
        savePressed == true;
      } else if (savePressed == true) {
        savePressed == false;
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(top: 18.0),
      child: GestureDetector(
        onTap: () {
          //You are referencing but not calling here, you should use ()
          buttonPressed();
          print(savePressed); //stays false for some reason
        },
        child: Container(
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(6),
            color: savePressed ? Colors.blue : Colors.red[400],
          ),
          child: Padding(
            padding: const EdgeInsets.symmetric(vertical: 8.0, horizontal: 40),
            child: Text(
              'I\'ll be Here!',
              style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
            ),
          ),
        ),
      ),
    );
  }
}

赞(0）回复(0）举报 2023-02-13

kadbb4592#

在GestureDetector中，您没有正确调用buttonPressed方法

GestureDetector(
        onTap: buttonPressed,
         ......

并通过更改为buttonPressed方法来优化代码

void buttonPressed() {
    setState(() {
      savePressed = !savePressed;
    });
  }

赞(0）回复(0）举报 2023-02-13

r55awzrz3#

试试这个，我稍微改变了一下你的buttonPressed方法，和手势检测器onTap。希望能有所帮助

import 'package:flutter/material.dart';

class VotingButton extends StatefulWidget {
  @override
  State<VotingButton> createState() => _VotingButtonState();
}

class _VotingButtonState extends State<VotingButton> {
  bool savePressed = false;

  void buttonPressed() {
    setState(() {
      savePressed = !savePressed;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(top: 18.0),
      child: GestureDetector(
        onTap: () {
          buttonPressed();
          print(savePressed);
        },
        child: Container(
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(6),
            color: savePressed ? Colors.blue : Colors.red[400],
          ),
          child: Padding(
            padding: const EdgeInsets.symmetric(vertical: 8.0, horizontal: 40),
            child: Text(
              'I\'ll be Here!',
              style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
            ),
          ),
        ),
      ),
    );
  }
}

赞(0）回复(0）举报 2023-02-13

jmp7cifd4#

请尝试以下代码：

import 'package:flutter/material.dart';

class VotingButton extends StatefulWidget {
  @override
  State<VotingButton> createState() => _VotingButtonState();
}

class _VotingButtonState extends State<VotingButton> {
  bool savePressed = false;

  void buttonPressed() {
    setState(() {
      savePressed = !savePressed;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(top: 18.0),
      child: GestureDetector(
        onTap: () {
          buttonPressed();
          print(savePressed);
        },
        child: Container(
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(6),
            color: savePressed ? Colors.blue : Colors.red[400],
          ),
          child: const Padding(
            padding:  EdgeInsets.symmetric(vertical: 8.0, horizontal: 40),
            child: Text(
              'I\'ll be Here!',
              style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
            ),
          ),
        ),
      ),
    );
  }
}

赞(0）回复(0）举报 2023-02-13

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flutter 振颤容器未在丝攻上更换

4条答案

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