如何使用Charts_flutter包在Flutter中显示工具提示 [英] How show tooltip In Flutter using charts_flutter package

问题描述

我在我的应用程序中使用 https://pub.dev/packages/charts_flutter .我想在按PointsLineChart中的点时显示工具提示.

I am using https://pub.dev/packages/charts_flutter For charts in my app. I want to show tooltip when I press point in PointsLineChart.

有什么方法可以显示工具提示?

Any way to show tooltip?

推荐答案

使用上述代码时，此代码的修改后的更正版本为:

There were some errors raising when using the above code the modified corrected version of this code is :

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:charts_flutter/flutter.dart';
// import 'package:charts_flutter/src/chart_canvas.dart' as eos;
import 'package:charts_flutter/src/text_element.dart' as TextElement;
import 'package:charts_flutter/src/text_style.dart' as style;

class Chart extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return LineChart(
      _createSampleData(),
      behaviors: [
        LinePointHighlighter(
          symbolRenderer: CustomCircleSymbolRenderer()
        )
      ],
      selectionModels: [
        SelectionModelConfig(
          changedListener: (SelectionModel model) {
            if(model.hasDatumSelection)
              print(model.selectedSeries[0].measureFn(model.selectedDatum[0].index));
          }
        )
      ],
    );
  }

  List<Series<LinearSales, int>> _createSampleData() {
    final data = [
      new LinearSales(0, 5),
      new LinearSales(1, 25),
      new LinearSales(2, 100),
      new LinearSales(3, 75),
    ];
    return [
      new Series<LinearSales, int>(
        id: 'Sales',
        colorFn: (_, __) => MaterialPalette.blue.shadeDefault,
        domainFn: (LinearSales sales, _) => sales.year,
        measureFn: (LinearSales sales, _) => sales.sales,
        data: data,
      )
    ];
  }
}

class CustomCircleSymbolRenderer extends CircleSymbolRenderer {

  @override
  void paint(ChartCanvas canvas, Rectangle<num> bounds, {List<int> dashPattern, Color fillColor, FillPatternType fillPattern, Color strokeColor, double strokeWidthPx}) {
    super.paint(canvas, bounds, dashPattern: dashPattern, fillColor: fillColor,fillPattern: fillPattern, strokeColor: strokeColor, strokeWidthPx: strokeWidthPx);
    canvas.drawRect(
      Rectangle(bounds.left - 5, bounds.top - 30, bounds.width + 10, bounds.height + 10),
      fill: Color.white
    );
    var textStyle = style.TextStyle();
    textStyle.color = Color.black;
    textStyle.fontSize = 15;
    canvas.drawText(

      TextElement.TextElement("1", style: textStyle),
        (bounds.left).round(),
        (bounds.top - 28).round()
    );
  }
}
class LinearSales {
  final int year;
  final int sales;
  LinearSales(this.year, this.sales);
}

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