基于WPF實(shí)現(xiàn)繪制地鐵路線圖

更新時間：2023年06月02日 11:16:24 作者：公子小六

經(jīng)常坐地鐵，卻不知道地鐵多少條線路？哪個站下車？本文就來帶大家利用WPF繪制深圳地鐵路線圖，從而帶大家掌握WPF在圖形繪制方面的一些知識，希望對大家有所幫助

WPF在繪制矢量圖方面有非常強(qiáng)大的優(yōu)勢，利用WPF可以繪制出各種矢量圖形，如線，圓，多邊形，矩形，及組合圖形。今天以繪制深圳地鐵路線圖為例，簡述WPF在圖形繪制方面的一些知識，僅供學(xué)習(xí)分享使用，如有不足之處，還請指正。

WPF圖形概述

與傳統(tǒng)的.NET開發(fā)使用GDI+進(jìn)行繪圖不同，WPF擁有自己的一套圖形API，繪圖為矢量圖。繪圖可以在任何一種布局控件中完成，wpf會根據(jù)容器計(jì)算相應(yīng)坐標(biāo)。最常用的是Canvas和Grid?；緢D形包括以下幾個，都是Shaper類的派生類。

Line，直線段，可以設(shè)置Stroke
Rectangle，有Stroke也有Fill
Ellipse，橢圓，同上
Polygon，多邊形。由多條直線線段圍成的閉合區(qū)域，同上。
Polyline，折線，不閉合，由多條首尾相接的直線段組成
Path，路徑，閉合?？梢杂扇舾芍本€、圓弧、貝塞爾曲線（由線段與節(jié)點(diǎn)組成，節(jié)點(diǎn)是可拖動的支點(diǎn)，線段像可伸縮的皮筋）組成。很強(qiáng)大。

地鐵官網(wǎng)效果

首先打開深圳地鐵官網(wǎng)【https://www.szmc.net/map/】，可查看深圳地鐵的路線圖，如下所示：

獲取地鐵路線數(shù)據(jù)

通過對地鐵官網(wǎng)的網(wǎng)絡(luò)接口接收數(shù)據(jù)分析，可以獲取地鐵數(shù)據(jù)的原始JSON文件，將原始JSON文件保存到本地，在程序中進(jìn)行引用，如下所示：

構(gòu)建地鐵數(shù)據(jù)模型

在得到shentie.json文件后，通過分析，構(gòu)建模型類，如下所示：

namespace DemoSubway.Models
{
    /// <summary>
    /// 深圳地鐵模型
    /// </summary>
    public class ShenTie
    {
        [JsonProperty("s")]
        public string? Name { get; set; }
        [JsonProperty("i")]
        public string? Index { get; set; }
        [JsonProperty("l")]
        public SubwayLine[]? SubwayLines { get; set; }
        [JsonProperty("o")]
        public string? Obj { get;set; }
    }
    public class SubwayLine
    {
        [JsonProperty("st")]
        public St[]? Sites { get; set; }
        [JsonProperty("ln")]
        public string? LineNumber { get; set; }
        [JsonProperty("su")]
        public string? Su { get; set; }
        [JsonProperty("kn")]
        public string? KName { get; set; }
        [JsonProperty("c")]
        public string[]? Circles { get;set; }
        [JsonProperty("lo")]
        public string? Lo { get; set; }
        [JsonProperty("lp")]
        public string[]? LinePosition { get; set; }
        [JsonProperty("ls")]
        public string? Ls { get; set; }
        [JsonProperty("cl")]
        public string? Color { get; set; }
        [JsonProperty("la")]
        public string? La { get; set; }
        [JsonProperty("x")]
        public string? X { get; set; }
        [JsonProperty("li")]
        public string? Li { get; set; }
    }
    public class St
    {
        [JsonProperty("rs")]
        public string? Rs { get; set; }
        [JsonProperty("udpx")]
        public string? Udpx { get; set; }
        [JsonProperty("su")]
        public string? Su { get; set; }
        [JsonProperty("udsu")]
        public string? Udsu { get; set;}
        [JsonProperty("n")]
        public string? Name { get; set;}
        [JsonProperty("en")]
        public string? En { get; set; }
        [JsonProperty("sid")]
        public string? Sid { get; set; }
        [JsonProperty("p")]
        public string? Position { get; set; }
        [JsonProperty("r")]
        public string? R { get; set; }
        [JsonProperty("udsi")]
        public string? Udsi { get; set; }
        [JsonProperty("t")]
        public string? T { get; set;}
        [JsonProperty("si")]
        public string? Si { get; set; }
        [JsonProperty("sl")]
        public string? Sl { get; set;}
        [JsonProperty("udli")]
        public string? Udli { get; set; }
        [JsonProperty("poiid")]
        public string? Poiid { get; set; }
        [JsonProperty("lg")]
        public string? Lg { get; set; }
        [JsonProperty("sp")]
        public string? Sp { get; set; }
    }
}

解析數(shù)據(jù)源

通過反序列化，將shentie.json文件內(nèi)容，加載到內(nèi)存并實(shí)例化為ShenTie對象，在此需要用到第三方庫【Newtonsoft.Json】，如下所示：

繪制地鐵路線圖

地鐵路線圖在WPF主頁面顯示，用Grid作為容器【subwayBox】，如下所示：

<Window x:Class="DemoSubway.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:DemoSubway"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" Loaded="Window_Loaded">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>
        <StackPanel Grid.Row="0" Orientation="Horizontal" HorizontalAlignment="Center">
            <TextBlock x:Name="tbTitle" FontSize="30" HorizontalAlignment="Center"></TextBlock>
        </StackPanel>
        <Viewbox Stretch="Fill" Grid.Row="1">
            <Grid x:Name="subwayBox">
            </Grid>
        </Viewbox>
    </Grid>
</Window>

ShenTie對象創(chuàng)建成功后，就可以獲取路線數(shù)據(jù)，然后創(chuàng)建地鐵路線元素，如下所示：

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    string jsonFile = "shentie.json";
    JsonHelper jsonHelper = new JsonHelper();
    var shentie = jsonHelper.Deserialize<ShenTie>(jsonFile);
    this.tbTitle.Text = shentie.Name;
    List<string> lstSites = new List<string>();
    for(int i = 0; i < shentie.SubwayLines?.Length; i++)
    {
        var subwayLine= shentie.SubwayLines[i];
        if(subwayLine != null)
        {
            //地鐵線路
            var color = ColorTranslator.FromHtml($"#{subwayLine.Color}");//線路顏色
            var circles = subwayLine.Circles;//線路節(jié)點(diǎn)
            Path line = new Path();
            PathFigureCollection lineFigures = new PathFigureCollection();
            PathFigure lineFigure = new PathFigure();
            lineFigure.IsClosed= false;
            var start = circles?[0].Split(" ");//線路起始位置
            lineFigure.StartPoint = new System.Windows.Point(int.Parse(start[0]), int.Parse(start[1]));
            for (int j= 0;j< circles?.Length;j++)
            {
                var circle= circles[j].Split(" ");
                LineSegment lineSegment = new LineSegment(new System.Windows.Point(int.Parse(circle[0]), int.Parse(circle[1])),true);
                lineFigure.Segments.Add(lineSegment);
            }
            lineFigures.Add(lineFigure);
            line.Data = new PathGeometry(lineFigures, FillRule.Nonzero, null);
            line.Stroke = new SolidColorBrush(System.Windows.Media.Color.FromArgb(color.A, color.R, color.G, color.B));
            line.StrokeThickness = 4;
            this.subwayBox.Children.Add(line);
            //地鐵站點(diǎn)
            for (int j = 0; j < subwayLine.Sites?.Length; j++)
            {
                var site = subwayLine.Sites[j];
                if (site != null)
                {
                    //站點(diǎn)標(biāo)識，圓圈
                    Path siteCirclePath = new Path();
                    var sitePosition = site?.Position?.Split(" ");
                    EllipseGeometry ellipse = new EllipseGeometry();
                    ellipse.Center = new System.Windows.Point(int.Parse(sitePosition[0]), int.Parse(sitePosition[1]));
                    ellipse.RadiusX = 4;
                    ellipse.RadiusY=4;
                    siteCirclePath.Data=ellipse;
                    siteCirclePath.Fill = Brushes.White;
                    siteCirclePath.Stroke = new SolidColorBrush(System.Windows.Media.Color.FromArgb(color.A, color.R, color.G, color.B));
                    siteCirclePath.Cursor= Cursors.Hand;
                    siteCirclePath.Focusable = true;
                    siteCirclePath.Tag = site?.Name;
                    siteCirclePath.MouseDown += SiteCirclePath_MouseDown;
                    this.subwayBox.Children.Add(siteCirclePath);
                    //站點(diǎn)名字
                    if (lstSites.Contains(site?.Name))
                    {
                        continue;//對于交匯站點(diǎn)，只繪制一次
                    }
                    //站點(diǎn)名稱
                    Path siteTextPath = new Path();
                    FormattedText siteContent = new FormattedText(site?.Name,CultureInfo.CurrentCulture,FlowDirection.LeftToRight,new Typeface("Arial"),14,Brushes.Black, 1.25);
                    var x = int.Parse(sitePosition[0]);
                    var y = int.Parse(sitePosition[1]);
                    if (j + 1 < subwayLine.Sites?.Length)
                    {
                        //站點(diǎn)位置適當(dāng)偏移
                        var next = subwayLine.Sites[j + 1]?.Position?.Split(" ");
                        var nextx = int.Parse(next[0]);
                        var nexty = int.Parse(next[1]);
                        if (x == nextx)
                        {
                            x = x + 6;
                        }
                        else if (y == nexty)
                        {
                            y = y + 6;
                        }
                        else
                        {
                            x = x + 1;
                            y = y + 1;
                        }
                    }
                    Geometry geometry = siteContent.BuildGeometry(new System.Windows.Point(x, y));
                    siteTextPath.Data = geometry;
                    siteTextPath.Stroke = Brushes.Black;
                    siteTextPath.Focusable = true;
                    siteTextPath.Cursor = Cursors.Hand;
                    siteTextPath.MouseDown += SiteTextPath_MouseDown;
                    siteTextPath.Tag = site?.Name;
                    this.subwayBox.Children.Add(siteTextPath);
                    lstSites.Add(site?.Name);
                }
            }
            var kName = subwayLine.KName;//線路名稱
            var linePosition= subwayLine.LinePosition?[0].Split(" ");
            if(kName != null)
            {
                Path lineNamePath = new Path();
                FormattedText lineNameText = new FormattedText(kName, CultureInfo.CurrentCulture,FlowDirection.LeftToRight,new Typeface("Arial"),16,Brushes.Black,1.25);
                var lineX = int.Parse(linePosition[0]);
                var lineY = int.Parse(linePosition[1]);
                if (subwayLine.LineNumber == "1")
                {
                    lineX = lineX - 10;
                    lineY = lineY + 20;
                }
                Geometry geometry = lineNameText.BuildGeometry(new System.Windows.Point(lineX, lineY));
                lineNamePath.Data=geometry;
                lineNamePath.Stroke = new SolidColorBrush(System.Windows.Media.Color.FromArgb(color.A, color.R, color.G, color.B));
                this.subwayBox.Children.Add(lineNamePath);
            }
        }
    }
}