〓 算法求教 〓 三色光栅移动时位置变换的有关问题

〓 算法求教 〓 三色光栅移动时位置变换的问题
static int iW, iInterval, i,k,n;

  private void button1_Click_1(object sender, EventArgs e)
  {
   
  iInterval = 3;
  i = iInterval;
  iW = 10;
  k = 0;
  n = 0;
  timer2.Interval = 100;
  this.timer2.Start();

  }

  private void timer2_Tick(object sender, EventArgs e)
  {
  if (i < iW)
  {
  if (k == 0)
  twinraster(Color.White, Color.Black,Color.Red, i, 0, 0, this.pictureBox1.Width, 0, iW);
  else if(k==1)
  twinraster(Color.Red, Color.White, Color.Black, i, 0, 0, this.pictureBox1.Width, 0, iW);
  else
  twinraster(Color.Black, Color.Red, Color.White, i, 0, 0, this.pictureBox1.Width, 0, iW);

  i += iInterval;
  }
  else
  {
  i = i - iW + 1;


  if (k == 0)
  {
  k = 1;
  n = 0;
  return;
  }
  if (k == 1)
  {
  if (n == 0)
  k = 2;
  else
  k = 0;
  return;
  }
  if (k == 2)
  {
  k = 1;
  n = 1;
  }
  //twinraster(Color.White, Color.Black, i, 0, 0, this.pictureBox1.Width, 0, iW);
   
  }
  }

private void twinraster(Color cColor1, Color cColor2,Color cColor3, int ist, int iX1, int iY1, int iX2, int iY2, int iWidth)//画三色光栅
  {
  Pen pen1 = new Pen(cColor1, iWidth);
  Pen pen2 = new Pen(cColor2, iWidth);
  Pen pen3 = new Pen(cColor1, ist);
  Pen pen4 = new Pen(cColor3, iWidth);

  Graphics myGraphics = this.pictureBox1.CreateGraphics();

  myGraphics.DrawLine(pen3, iX1, 0, iX2, 0);

  iY1 = ist;
  iY2 = ist;

  for (; iY1 <= this.pictureBox1.Height; iY1 += iWidth, iY2 += iWidth)
  {
  myGraphics.DrawLine(pen2, iX1, iY1, iX2, iY2);
  iY1 += iWidth;
  iY2 += iWidth;
  myGraphics.DrawLine(pen4, iX1, iY1, iX2, iY2);
  iY1 += iWidth;
  iY2 += iWidth;
  myGraphics.DrawLine(pen1, iX1, iY1, iX2, iY2);
  }
  myGraphics.DrawLine(pen2, iX1, iY1, iX2, iY2);
  }

我是这样写的，但是算法的效率肯定很差，而且在移动的时候，有一个地方会出错，颜色没控制得好，我已经弄了好久都没解决这个问题。主要是自己的算法已经一塌糊涂了，望知道的朋友帮忙看一下，谢谢了

[解决办法]
参考如下代码

C# code

private void timer1_Tick(object sender, EventArgs e){    yOffset = (yOffset + speed) % (lineHeight * lineColors.Length);    pictureBox1.Refresh();}private void button1_Click(object sender, EventArgs e){    timer2.Enabled = !timer2.Enabled;}/// <summary>/// 线的高度/// </summary>private int lineHeight = 10;/// <summary>/// 线条的颜色/// </summary>private Color[] lineColors = new Color[] {     Color.White, Color.Black, Color.Red, Color.Green };/// <summary>/// 横向偏移/// </summary>private int yOffset = 0;/// <summary>/// 滚动的速度/// </summary>private int speed = 2;/// <summary>/// 绘制全部线条/// </summary>/// <param name="AGraphics">绘制的画布</param>private void DrawFace(Graphics AGraphics){    int vIndex = 0; // 向下绘制    for (int y = yOffset; y < AGraphics.ClipBounds.Height; y += lineHeight)    {        AGraphics.FillRectangle(new SolidBrush(lineColors[vIndex]),            new RectangleF(0, y, AGraphics.ClipBounds.Width, lineHeight));        vIndex = (vIndex + 1) % lineColors.Length;    }    vIndex = lineColors.Length - 1; // 向上绘制    for (int y = yOffset - lineHeight; y >= -lineHeight; y -= lineHeight)    {        vIndex = (vIndex + 1) % lineColors.Length;        AGraphics.FillRectangle(new SolidBrush(            lineColors[lineColors.Length - vIndex - 1]),            new RectangleF(0, y, AGraphics.ClipBounds.Width, lineHeight));    }}private void pictureBox1_Paint(object sender, PaintEventArgs e){    DrawFace(e.Graphics);}