C#绘制蚂蚁线

delegate void LINEDDAPROC(int X, int Y, IntPtr lpData);

[DllImport("gdi32.dll")]

static extern int LineDDA(int nXStart, int nYStart, int nXEnd, int nYEnd,

    LINEDDAPROC lpLineFunc, IntPtr lpData);

 

private const byte PT_CLOSEFIGURE = 1;

private const byte PT_LINETO = 2;

private const byte PT_BEZIERTO = 4;

private const byte PT_MOVETO = 6;

 

[DllImport("gdi32.dll")]

static extern int SetPixel(IntPtr hdc, int X, int Y, int crColor);

 

GraphicsPath graphicsPath = new GraphicsPath();

private int counter = 0;

private IntPtr graphicsHandle = IntPtr.Zero;

//设计Zswang 2007-04-30 wjhu111#21cn.com 尊重作者,转贴请注明出处

 

private void button1_Click(object sender, EventArgs e)

{

    graphicsPath.ClearMarkers();

    graphicsPath.AddRectangle(new Rectangle(10, 10, 100, 100));

    timer1.Interval = 100;

    timer1.Enabled = true;

}

 

private void MovingDots(int X, int Y, IntPtr lpData)

{

    counter = (counter + 1) % 15;

    Color vColor;

    if (counter < 5)

        vColor = Color.White;

    else if (counter < 12)

        vColor = Color.Red;

    else vColor = Color.Blue;

    SetPixel(graphicsHandle, X, Y, vColor.R | vColor.G << 8 | vColor.B << 16);

}

 

private void timer1_Tick(object sender, EventArgs e)

{

    graphicsHandle = Graphics.FromHwnd(Handle).GetHdc();

    for (int i = 0; i < graphicsPath.PathPoints.Length; i++)

    {

        if (graphicsPath.PathTypes[i] == (byte)(PT_CLOSEFIGURE | PT_LINETO))

        {

            for (int j = i; j >= 0; j--)

            {

                if (graphicsPath.PathTypes[j] == PT_MOVETO)

                {

                    LineDDA(

                        (int)graphicsPath.PathPoints[i].X,

                        (int)graphicsPath.PathPoints[i].Y,

                        (int)graphicsPath.PathPoints[j].X,

                        (int)graphicsPath.PathPoints[j].Y,

                        MovingDots, IntPtr.Zero);

                    break;

                }

            }

            continue;

        }

        if (i == graphicsPath.PathPoints.Length - 1)

            LineDDA(

                (int)graphicsPath.PathPoints[i].X,

                (int)graphicsPath.PathPoints[i].Y,

                (int)graphicsPath.PathPoints[0].X,

                (int)graphicsPath.PathPoints[0].Y,

                MovingDots, IntPtr.Zero);

        else

            LineDDA(

                (int)graphicsPath.PathPoints[i].X,

                (int)graphicsPath.PathPoints[i].Y,

                (int)graphicsPath.PathPoints[i + 1].X,

                (int)graphicsPath.PathPoints[i + 1].Y,

                MovingDots, IntPtr.Zero);

    }

}