以上所生成的为简单的验证码。接下来我从其他的博客中学习了其他形式的效果。
/* 图片画线特殊效果：贝塞尔曲线 */
Graphics graph = Graphics.FromImage(image);
graph.Clear(Color.WhiteSmoke);
Point[] myArray ={
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50)),
new Point(random.Next(150),random.Next(50))
};
Pen myPen = new Pen(Color.Blue, 1);
GraphicsPath myPath = new GraphicsPath();
myPath.AddBeziers(myArray);
graph.DrawPath(myPen, myPath);
验证码字符颜色变换效果：实现该效果，我们首先来定义一个颜色集合，然后通过for循环使其随机改变字体颜色则可。
#region 定义颜色数组
Color[] colors = { Color.Blue, Color.Green, Color.Red, Color.Gold, Color.Black, Color.Chocolate, Color.Orange, Color.Purple };
public Color[] Colors
{
get { return colors; }
set { colors = value; }
}
#endregion
Brush brush;
int colornum;
for(int i=0; i
{
colornum = random.Next(Colors.Length - 1);
brush = new System.Drawing.SolidBrush(Colors[cindex]);
//利用DrawString函数进行颜色填充就可以了。
}
同样的原理我们也可以定义一个字体的数组来进行验证码字体切换。代码和颜色的类似，这里就不加以累赘。
接下来看看如何使得验证码的字体进行扭曲。
private const double PI = 3.1415926535897932384626433832795;
private const double PI2 = 6.283185307179586476925286766559;
///
/// 波形滤镜效果函数
///
///
///
///
///
///
public System.Drawing.Bitmap TwistImage(Bitmap srcbmp, double dmultvalue, double dphase)
{
System.Drawing.Bitmap destbmp = new Bitmap(srcbmp.Width,srcbmp.Height);
System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destbmp);
//填充背景图为白色
graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destbmp.Width, destbmp.Height);
graph.Dispose();
double dbaselen = (double)destbmp.Width;
for (int i = 0; i < destbmp.Width; i++)
{
for (int j = 0; j < destbmp.Height; j++)
{
double dx = 0;
dx = (PI2 * (double)j) / dbaselen;
dx += dphase;
double dy = Math.Sin(dx);
int noldx = 0, noldy = 0;
noldx = i + (int)(dy * dmultvalue);
noldy = j + (int)(dy * dmultvalue);
System.Drawing.Color color = srcbmp.GetPixel(i, j);
if (noldx >= 0 && noldx < destbmp.Width && noldy >= 0 && noldy < destbmp.Height)
destbmp.SetPixel(noldx, noldy, color);
}
}
return destbmp;
}
