Flutter 自定义虚线进度条

实现效果

//使用

DotProgressWidget(

                          progress: Progress(

                            backgroundColor: Colors.grey,

                            value: 0.8,

                            width: 300,

                            color: Colors.green,

                            strokeWidth: 8

                          ),


//实现代码

import 'package:flutter/material.dart';

class DotProgressWidget extends StatefulWidget {

  final Progress progress;

  DotProgressWidget({Key key, this.progress}) : super(key: key);

  @override

  _DotProgressWidgetState createState() => _DotProgressWidgetState();

}

///信息描述类 [value]为进度,在0~1之间,进度条颜色[color],

///未完成的颜色[backgroundColor],线宽[strokeWidth]

///小点的个数[dotCount],进度条宽度[width] 

class Progress {

  double value;

  Color color;

  Color backgroundColor;

  double width;

  double strokeWidth;

  int dotCount;

  Progress(

      {this.value,

      this.color,

      this.backgroundColor,

      this.width,

      this.strokeWidth,

      this.dotCount = 30});

}

class _DotProgressWidgetState extends State {

  @override

  Widget build(BuildContext context) {

    var progress = Container(

      width: widget.progress.width,

      height: widget.progress.strokeWidth,

      child: CustomPaint(

        painter: ProgressPainter(widget.progress),

      ),

    );

    return Stack(

      alignment: Alignment.center,

      children: [progress],

    );

  }

}

class ProgressPainter extends CustomPainter {

  Progress _progress;

  Paint _paint;

  ProgressPainter(

    this._progress,

  ) {

    _paint = Paint();

  }

  @override

  void paint(Canvas canvas, Size size) {

    // Rect rect = Offset.zero & size;

    // canvas.clipRect(rect); //裁剪区域

    drawProgress(canvas);

  }

  void drawProgress(Canvas canvas) {

    canvas.save();

    int num = _progress.dotCount;

    double gap = _progress.width / (_progress.dotCount);

    Offset currentPoint = Offset(0, 0);

    for (double i = 0; i < num; i++) {

      canvas.save();

      _paint

        ..strokeWidth = _progress.strokeWidth

        ..color = _progress.backgroundColor

        ..strokeCap = StrokeCap.round;

      if (i < _progress.value * num) {

        _paint..color = _progress.color;

      }

      double toSiteX = currentPoint.dx;

      canvas.drawLine(

          currentPoint, Offset(toSiteX, _progress.strokeWidth), _paint);

      currentPoint = Offset(

          currentPoint.dx + gap,

          currentPoint.dy,

        );

      canvas.restore();

    }

    canvas.restore();

  }

  @override

  bool shouldRepaint(CustomPainter oldDelegate) {

    return true;

  }

}

你可能感兴趣的:(Flutter 自定义虚线进度条)