Flutter：如何在聊天消息中制作电报类型气泡

Question

电流输出：

预期输出：

---

代码：

Align(
  alignment: Alignment.topRight,
  child: Container(
    padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 20),
    margin: EdgeInsets.only(right: 12, top: 8),
    decoration: BoxDecoration(
      color: Color(0xFF486993),
      borderRadius: BorderRadius.all(Radius.circular(20)),
    ),
    child: Text("This is my message"),
  ),
)

Answer 1

这正是在 Flutter 中创建整洁的语音气泡所需要的。

首先创建一个扩展 Painter 类的自定义 Painter 类

class CustomChatBubble extends CustomPainter {
  CustomChatBubble({this.color, @required this.isOwn});

  final Color color;
  final bool isOwn;

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()..color = color ?? Colors.blue;

    Path paintBubbleTail() {
      Path path;
      if (!isOwn) {
        path = Path()
          ..moveTo(5, size.height - 5)
          ..quadraticBezierTo(-5, size.height, -16, size.height - 4)
          ..quadraticBezierTo(-5, size.height - 5, 0, size.height - 17);
      }
      if (isOwn) {
        path = Path()
          ..moveTo(size.width - 6, size.height - 4)
          ..quadraticBezierTo(
              size.width + 5, size.height, size.width + 16, size.height - 4)
          ..quadraticBezierTo(
              size.width + 5, size.height - 5, size.width, size.height - 17);
      }
      return path;
    }

    final RRect bubbleBody = RRect.fromRectAndRadius(
        Rect.fromLTWH(0, 0, size.width, size.height), Radius.circular(16));
    final Path bubbleTail = paintBubbleTail();

    canvas.drawRRect(bubbleBody, paint);
    canvas.drawPath(bubbleTail, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    // TODO: implement shouldRepaint
    return true;
  }
}

然后在您的聊天屏幕中使用它。请注意，此屏幕仅用于演示目的，您可以根据需要进行修改。

class ChatSampleWidget extends StatefulWidget {
  @override
  _ChatSampleWidgetState createState() => _ChatSampleWidgetState();
}

class _ChatSampleWidgetState extends State<ChatSampleWidget> {
  TextEditingController _editingController = TextEditingController();
  FocusNode _focusNode = FocusNode();
  final TextStyle textStyle = TextStyle(color: Colors.white);
  @override
  void initState() {
    super.initState();
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Chatter'),
      ),
      body: SafeArea(
        child: Stack(
          children: <Widget>[
            Container(
              padding: EdgeInsets.all(20),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.start,
               
                children: <Widget>[
                  Row(
                    mainAxisAlignment: MainAxisAlignment.start,
                    children: <Widget>[
                      CustomPaint(
                          painter: CustomChatBubble(isOwn: false),
                          child: Container(
                              padding: EdgeInsets.all(8),
                              child: Text(
                                'Message from someone else \n Says sometihngs',
                                style: textStyle,
                              ))),
                    ],
                  ),
                  SizedBox(
                    height: 5,
                  ),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.start,
                    children: <Widget>[
                      CustomPaint(
                          painter:
                              CustomChatBubble(color: Colors.grey, isOwn: false),
                          child: Container(
                              padding: EdgeInsets.all(10),
                              child: FlutterLogo())),
                    ],
                  ),
                  SizedBox(
                    height: 5,
                  ),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.end,
                    children: <Widget>[
                      CustomPaint(
                          painter:
                              CustomChatBubble(color: Colors.green, isOwn: true),
                          child: Container(
                              padding: EdgeInsets.all(8),
                              child: Text(
                                'Message from me',
                                style: textStyle,
                              ))),
                    ],
                  )
                ],
              ),
            ),
            Positioned(
                bottom: 0,
                child: Container(
                  padding: EdgeInsets.all(8),
                  width: MediaQuery.of(context).size.width,
                  color: Colors.grey.withOpacity(0.1),
                  child: Row(
                    mainAxisAlignment: MainAxisAlignment.spaceAround,
                    children: <Widget>[
                      Flexible(
                        child: TextField(
                          controller: _editingController,
                          focusNode: _focusNode,
                          decoration:
                              InputDecoration(hintText: 'Say something...'),
                        ),
                      ),
                      IconButton(
                          icon: Icon(
                            Icons.send,
                            size: 30,
                          ),
                          onPressed: () {
                            print(_editingController.text);
                          })
                    ],
                  ),
                ))
          ],
        ),
      ),
    );
  }
}

这就是它的样子；

Answer 2

你在这里：

import 'package:flutter/material.dart';

void main() => runApp(
    MyApp()
);

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Padding(
        padding: EdgeInsets.all(7),
        child: Align(
          alignment: Alignment.centerRight,
          child: Stack(
            children: [
              Container(
                padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 20),
                decoration: BoxDecoration(
                  color: Color(0xFF486993),
                  borderRadius: BorderRadius.all(Radius.circular(20)),
                ),
                child: Row(
                  mainAxisSize: MainAxisSize.min,
                  children: <Widget>[
                    RichText(
                      text: TextSpan(
                        children: <TextSpan>[
                          TextSpan(
                            text: 'This is telegram message   ',
                            style: TextStyle(
                                color: Colors.white,
                                fontSize: 14.0
                            ),
                          ),
                          TextSpan(
                            text: '3:16 PM',
                            style: TextStyle(
                                color: Colors.grey,
                                fontSize: 12.0,
                                fontStyle: FontStyle.italic
                            ),
                          ),
                        ],
                      ),
                    ),
                    Icon(Icons.check, color: Color(0xFF7ABAF4), size: 16,)
                  ]
                ),
              ),
              Positioned(
                bottom: 0,
                right: 0,
                child: CustomPaint(
                  painter: ChatBubbleTriangle(),
                )
              )
            ]
          )
        ),
      ),
    );
  }
}

class ChatBubbleTriangle extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    var paint = Paint()..color = Color(0xFF486993);

    var path = Path();
    path.lineTo(-15, 0);
    path.lineTo(0, -15);
    path.lineTo(0, 0);
    canvas.drawPath(path, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    return true;
  }
}

您将不得不更改paint 方法，因为现在它只是一个三角形。

否则，它看起来像您要求的那样。

Answer 3

尝试自己重新创建 Telegram 布局，我想出了这个来制作形状；

enum _TailDirection { right, left }

class ChatBubblePainter extends CustomPainter {
  ChatBubblePainter({this.color, this.isSentByMe});

  final Color color;
  final bool isSentByMe;

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()..color = color;

    Path paintBubbleTail(_TailDirection direction) {
      double startingPoint;
      double point;
      double endPoint;
      double curvePoint;
      if (direction == _TailDirection.right) {
        startingPoint = size.width - 5;
        point = size.width + 10;
        endPoint = size.width + 3;
        curvePoint = size.width;
      }
      if (direction == _TailDirection.left) {
        startingPoint = 5;
        point = -10;
        endPoint = -3;
        curvePoint = 0;
      }
      return Path()
        ..moveTo(startingPoint, size.height)
        ..lineTo(point, size.height)
        ..quadraticBezierTo(endPoint, size.height, curvePoint, size.height - 10);
    }

    final RRect bubbleBody = RRect.fromRectAndRadius(
        Rect.fromLTWH(0, 0, size.width, size.height), Radius.circular(5.0));
    final Path bubbleTail = isSentByMe
        ? paintBubbleTail(_TailDirection.right)
        : paintBubbleTail(_TailDirection.left);

    canvas.drawRRect(bubbleBody, paint);
    canvas.drawPath(bubbleTail, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    // TODO: implement shouldRepaint
    return true;
  }
}