c# - 如何在 C# 中链接 XY 条形图中的两个 sql 列

Question

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Web.UI.DataVisualization.Charting;
using System.Windows.Forms.DataVisualization.Charting;
using System.Data.SqlClient;

namespace BAR_CHART
{
public partial class Form1 : Form
{
    private DataTable dataTable = new DataTable();
    public SqlConnection con = new SqlConnection(@"server=$$$$;database=$$$$$;uid=$$$$;password=$$$$$;MultipleActiveResultSets=True");
    public SqlCommand cmd, cmd1;
    public SqlDataReader dr1, dr2;
    public Form1()
    {
        InitializeComponent();
    }

    private void chart1_Click(object sender, EventArgs e)
    {
        {
            BarExample(); //Show bar chart
            //SplineChartExample();
        }

    }
    public void BarExample()
    {
        this.chart1.Series.Clear();
        string SelectMeterMaster = "Select PLC_ID from [DB].[dbo].[MASTER] ";
        string SelectMeterMaster1 = "Select V_Ph_a from [DB].[dbo].[MASTER] ";
        //  dataTable.AsEnumerable().Select(r => r.Field<string>("ID")).ToArray();


        cmd = new SqlCommand(SelectMeterMaster, con);
        con.Open();
        dr1 = cmd.ExecuteReader();

        if (dr1.Read())
        {


            string[] seriesArray = { SelectMeterMaster };
            int[] pointsArray = { 2 };

            // Set palette
            this.chart1.Palette = System.Windows.Forms.DataVisualization.Charting.ChartColorPalette.EarthTones;

            // Set title
            this.chart1.Titles.Add("Meter");

            // Add series.
            for (int i = 0; i < seriesArray.Length; i++)
            {
                System.Windows.Forms.DataVisualization.Charting.Series series = this.chart1.Series.Add(seriesArray[i]);
                series.Points.Add(pointsArray[i]);
            }
        }
     }
       }

   }

我想在我的 XY 条形图中映射两个 sql 列值 我在表中有大约 10 个条目，我想将它们绘制成条形图。我在获取变量中的 10 列值时遇到问题，以便我可以将其传递到 string[] seriesArray 中。

Answer 1

这是一个简单的 winform 图表示例:

/// <summary>
/// Chart data
/// </summary>
public class PointChart
{

    public string SeryName { get; set; }

    public int XValue { get; set; }

    public int YValue { get; set; }
}

/// <summary>
/// Create series and points
/// </summary>
/// <param name="listChartItems"></param>
private void BindDataToChart(List<PointChart> listChartItems)
    {
        if (listChartItems == null || listChartItems.Count == 0) return;

        chart1.Series.Clear();

        var listSeries = listChartItems.Select(x => new { x.SeryName }).Distinct().ToList();

        // Add list series
        foreach (var sery in listSeries)
        {
            var newSery = new Series(sery.SeryName);

            var listPoints = listChartItems.Where(x => x.SeryName == sery.SeryName).ToList();

            // Add sery's points
            foreach (var point in listPoints)
            {
                newSery.Points.Add(new DataPoint(point.XValue, point.YValue));
            }

            chart1.Series.Add(newSery);
        }
    }

您可以像这样将数据绑定(bind)到 Form_Load 中的图表

    private void ChartSample_Load(object sender, EventArgs e)
    {
        var listChartItems = new List<PointChart>();
        listChartItems.Add(new PointChart { SeryName = "Seri 1",XValue = 2,YValue = 3});
        listChartItems.Add(new PointChart { SeryName = "Seri 1",XValue = 3,YValue = 5});
        listChartItems.Add(new PointChart { SeryName = "Seri 1",XValue = 4,YValue = 7});
        listChartItems.Add(new PointChart { SeryName = "Seri 1",XValue = 5,YValue = 9});

        listChartItems.Add(new PointChart { SeryName = "Seri 2", XValue = 1, YValue = 10 });
        listChartItems.Add(new PointChart { SeryName = "Seri 2", XValue = 8, YValue = 11 });
        listChartItems.Add(new PointChart { SeryName = "Seri 2", XValue = 4, YValue = 5});
        listChartItems.Add(new PointChart { SeryName = "Seri 2", XValue = 6, YValue = 3 });

        BindDataToChart(listChartItems);
    }