学过C#的请进…

//在窗体上画矩形，鼠标按下拖动就行了，颜色你自己改就可以了
Point p;
public void DrawRect(Rectangle rect)
{
SolidBrush brush = new SolidBrush(Color.FromArgb(20,0,0,255));
Graphics g = this.CreateGraphics();
g.FillRectangle(brush, rect);
brush.Dispose();
g.Dispose();
}

Rectangle[] hasDrawed = new Rectangle[100];
int index = 0;
bool IsDown = false;
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
IsDown = true;
p = e.Location;
}
}

private void Form1_MouseUp(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
IsDown = false;
hasDrawed[index] = lastRect;
index++;
lastRect = new Rectangle(new Point(0, 0), new Size(0, 0));
}
}

public void ClearRect(Rectangle r)
{
SolidBrus