//点击左键
private void panel_MouseDown(object sender, MouseEventArgs e)
{
//GDI+定义画图对象
Image map = new Bitmap(panel.Width, panel.Height);
Graphics g = Graphics.FromImage(map);
//画线对象
Pen linePen = new Pen(Color.Black, 2);
//画点对象
Pen pointPen = new Pen(Color.Red, 2);
//实例化点对象
Point newPoint = new Point(e.X, e.Y);
//将点对象加入点列表中
points.pointList.Add(newPoint);
//当点数大于三时，实例化对象并调构造函数，存入点，创建三角形
if (points.pointList.Count > 2)
{
Construction_TIN delaunay = new Construction_TIN(this.points);
//此时triangles不再是null
triangles = delaunay.Triangle_const();
}
//遍历点列表，画点
for (int j = 0; j < points.Count; j++)
{
g.DrawEllipse(pointPen, points[j].X, points[j].Y, 2f, 2f);
}
//如果三角形列表不为空，画出三角形的边
if (triangles != null)
{
for (int i = 0; i < triangles.Count; i++)
{
Triangle triangle = triangles[i];
g.DrawLine(linePen, triangle.Edge1.pa.X, triangle.Edge1.pa.Y, triangle.Edge1.pb.X, triangle.Edge1.pb.Y);
g.DrawLine(linePen, triangle.Edge2.pa.X, triangle.Edge2.pa.Y, triangle.Edge2.pb.X, triangle.Edge2.pb.Y);
g.DrawLine(linePen, triangle.Edge3.pa.X, triangle.Edge3.pa.Y, triangle.Edge3.pb.X, triangle.Edge3.pb.Y);
}
}
//返回给面板，重绘面板，用于显示
this.panel.BackgroundImage = map;
}
//构造函数用于给以上声明的两个列表初始化
public Construction_TIN(PointList points)
{
this.pointlist = points;
this.triangles = new TriangleList();
}
private void button1_Click(object sender, EventArgs e)
{
points = new PointList();
triangles = null;
this.panel.BackgroundImage = null;
}
