GraphicsPath相当难的问题

在Winform中随机生成100个小圆，当鼠标移上去时，显示当前是哪一个圆（索引或坐标），坐等大家回复！！

原码如下：
using System;
using System.Drawing;
using System.Windows.Forms;

namespace DrawDeom
{
public partial class Form2 : Form
{
private Point[] aDraw = new Point[100];
System.Drawing.Drawing2D.GraphicsPath path = new System.Drawing.Drawing2D.GraphicsPath();

public Form2()
{
InitializeComponent();
Run100();
}

private void Run100()
{
System.Random rnd = new Random();

int x, y;

for (int i = 0; i < aDraw.Length; i++)
{
x = rnd.Next(this.Width);
y = rnd.Next(this.Height);
aDraw[i].X = x;
aDraw[i].Y = y;

path.AddEllipse(x, y, 5, 5);
}
}

private void Draw(Graphics _g)
{
Pen redPen = new Pen(Color.Red, 1);
_g.DrawPath(redPen, path);
}

protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
Draw(e.Graphics);
}

protected override void OnMouseMove(MouseEventArgs e)
{
Point p = System.Windows.Forms.Control.MousePosition;
toolStripStatusLabel1.Text = string.Format("X:{0}-Y{1}", p.X, p.Y);
p = this.PointToClient(p);
if (path.IsVisible(p.X, p.Y))
{
toolStripStatusLabel1.ForeColor = Color.Red;
toolTip1.ToolTipTitle = "标题";
//显示当前圆的索引或左上角坐标
toolTip1.Show("当前图形：XX", this);
}
else
{
toolStripStatusLabel1.ForeColor = Color.Black;
toolTip1.Hide(this);
}
}
}
}