绘制曲线

Question

尝试绘制一个二次函数，其中用户输入 a、b、c (ax^2 + bx + c)。我已经制作了一个计算根的函数，现在我必须尝试绘制图形。我复制了微软的贝塞尔曲线示例，它可以编译，但没有输出。任何帮助都会很棒

    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;


     namespace graph
      { 
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {

    }

    public void drawBeziers(Pen pen, Point[] coordinates)
    {
    }
    private void quadGraph(PaintEventArgs e)
    {
      Pen blackPen = new Pen(Color.Black, 3);

      Point start = new Point(100, 100);
      Point control1 = new Point(200, 10);
      Point control2 = new Point(350, 50);
      Point end1 = new Point(500, 100);
      Point control3 = new Point(600, 150);
      Point control4 = new Point(650, 250);
      Point end2 = new Point(500, 300);
      Point[] bezierPoints = 
                 {
                     start, control1, control2, end1, 
                     control3, control4, end2
                 };

      e.Graphics.DrawBeziers(blackPen, bezierPoints);



    }

Answer 1

你甚至不调用 quadGraph()，把它添加到你的类中：

protected override void OnPaint(PaintEventArgs pe)
{
   base.OnPaint(pe);
   quadGraph(pe);
}