Dispenser/DispenserUI/Views/Controls/Histogram.axaml.cs

using System;
using System.Linq;
using Avalonia;
using Avalonia.Controls;
using Avalonia.Markup.Xaml;
using Avalonia.Media;
using Masuit.Tools;

namespace DispenserUI.Views.Controls;

public partial class Histogram : UserControl
{
    public static readonly DirectProperty<Histogram, double[]> DataProperty =
        AvaloniaProperty.RegisterDirect<Histogram, double[]>(
            nameof(Data),
            o => o.Data,
            (o, v) => o.Data = v);


    private double[] _data = Array.Empty<double>();

    public Histogram()
    {
        InitializeComponent();
    }

    public double[] Data
    {
        get => _data;
        set
        {
            SetAndRaise(DataProperty, ref _data, value);
            InvalidateVisual(); // 重绘控件
        }
    }

    private void InitializeComponent()
    {
        AvaloniaXamlLoader.Load(this);
    }


    protected override void OnSizeChanged(SizeChangedEventArgs e)
    {
        base.OnSizeChanged(e);
        InvalidateVisual();
    }

    public override void Render(DrawingContext context)
    {
        base.Render(context);

        if (Data.IsNullOrEmpty()) return; // 如果没有数据，则不绘制

        var width = Bounds.Width; // 控件宽度
        var height = Bounds.Height; // 控件高度

        var maxDataValue = Data.Max();

        var columnsCount = Data.Length;
        var spaceRatio = 0.2; // 柱体间空隙占柱体宽度的比例
        var columnWidth = width / (columnsCount + columnsCount * spaceRatio - spaceRatio); // 计算柱体宽度
        var spaceWidth = columnWidth * spaceRatio; // 计算柱体间空隙宽度

        for (var i = 0; i < columnsCount; i++)
        {
            var columnHeight = Data[i] / maxDataValue * height; // 根据数据值计算柱体高度
            var rect = new Rect(i * (columnWidth + spaceWidth), height - columnHeight, columnWidth, columnHeight);
            context.FillRectangle(Brushes.Blue, rect); // 绘制柱体
        }
    }
}