一个无刷新仿google波形扭曲彩色Asp.net验证码，源代码来自51aspx。
由于转载自网上也不详细说了，呵呵我也是只是把code复制过来测试了一下效果而已的。
主要有三个文件
VerifyCode.cs是生成验证码的类库文件，核心
VerifyCodes.aspx：调用上面的类库来生成验证码的页面文件
Index.aspx：前台显示验证码的页面文件
下面就是全部的代码
1.VerifyCode.cs文件
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
///<summary>
/// VerifyCode 的摘要说明
///</summary>
publicclassVerifyCode
{
#region验证码长度(默认6个验证码的长度)
int length = 6;
publicint Length
{
get { return length; }
set { length = value; }
}
#endregion
#region验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改)
int fontSize = 40;
publicint FontSize
{
get { return fontSize; }
set { fontSize = value; }
}
#endregion
#region边框补(默认1像素)
int padding = 2;
publicint Padding
{
get { return padding; }
set { padding = value; }
}
#endregion
#region是否输出燥点(默认不输出)
bool chaos = true;
publicbool Chaos
{
get { return chaos; }
set { chaos = value; }
}
#endregion
#region输出燥点的颜色(默认灰色)
Color chaosColor = Color.LightGray;
publicColor ChaosColor
{
get { return chaosColor; }
set { chaosColor = value; }
}
#endregion
#region自定义背景色(默认白色)
Color backgroundColor = Color.White;
publicColor BackgroundColor
{
get { return backgroundColor; }
set { backgroundColor = value; }
}
#endregion
#region自定义随机颜色数组
Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
publicColor[] Colors
{
get { return colors; }
set { colors = value; }
}
#endregion
#region自定义字体数组
string[] fonts = { "Arial", "Georgia", "courier new" };
publicstring[] Fonts
{
get { return fonts; }
set { fonts = value; }
}
#endregion
#region自定义随机码字符串序列(使用逗号分隔)
string codeSerial = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
publicstring CodeSerial
{
get { return codeSerial; }
set { codeSerial = value; }
}
#endregion
#region产生波形滤镜效果
privateconstdouble PI = 3.1415926535897932384626433832795;
privateconstdouble PI2 = 6.283185307179586476925286766559;
///<summary>
///正弦曲线Wave扭曲图片（Edit By 51aspx.com）
///</summary>
///<param name="srcBmp">图片路径</param>
///<param name="bXDir">如果扭曲则选择为True</param>
///<param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param>
///<param name="dPhase">波形的起始相位，取值区间[0-2*PI)</param>
///<returns></returns>
public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
{
System.Drawing.Bitmap destBmp = newBitmap(srcBmp.Width, srcBmp.Height);
// 将位图背景填充为白色
System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp);
graph.FillRectangle(newSolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height);
graph.Dispose();
double dBaseAxisLen = bXDir ? (double)destBmp.Height : (double)destBmp.Width;
for (int i = 0; i < destBmp.Width; i++)
{
for (int j = 0; j < destBmp.Height; j++)
{
double dx = 0;
dx = bXDir ? (PI2 * (double)j) / dBaseAxisLen : (PI2 * (double)i) / dBaseAxisLen;
dx += dPhase;
double dy = Math.Sin(dx);
// 取得当前点的颜色
int nOldX = 0, nOldY = 0;
nOldX = bXDir ? i + (int)(dy * dMultValue) : i;
nOldY = bXDir ? j : 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;
}
#endregion
#region生成校验码图片
publicBitmap CreateImageCode(string code)
{
int fSize = FontSize;
int fWidth = fSize + Padding;
int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2;
int imageHeight = fSize * 2 + Padding;
System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight);
Graphics g = Graphics.FromImage(image);
g.Clear(BackgroundColor);
Random rand = newRandom();
//给背景添加随机生成的燥点
if (this.Chaos)
{
Pen pen = newPen(ChaosColor, 0);
int c = Length * 10;
for (int i = 0; i < c; i++)
{
int x = rand.Next(image.Width);
int y = rand.Next(image.Height);
g.DrawRectangle(pen, x, y, 1, 1);
}
}
int left = 0, top = 0, top1 = 1, top2 = 1;
int n1 = (imageHeight - FontSize - Padding * 2);
int n2 = n1 / 4;
top1 = n2;
top2 = n2 * 2;
Font f;
Brush b;
int cindex, findex;
//随机字体和颜色的验证码字符
for (int i = 0; i < code.Length; i++)
{
cindex = rand.Next(Colors.Length - 1);
findex = rand.Next(Fonts.Length - 1);
f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);
b = new System.Drawing.SolidBrush(Colors[cindex]);
if (i % 2 == 1)
{
top = top2;
}
else
{
top = top1;
}
left = i * fWidth;
g.DrawString(code.Substring(i, 1), f, b, left, top);
}
//画一个边框边框颜色为Color.Gainsboro
g.DrawRectangle(newPen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1);
g.Dispose();
//产生波形（Add By 51aspx.com）
image = TwistImage(image, true, 8, 4);
return image;
}
#endregion
#region将创建好的图片输出到页面
publicvoid CreateImageOnPage(string code, HttpContext context)
{
System.IO.MemoryStream ms = new System.IO.MemoryStream();
Bitmap image = this.CreateImageCode(code);
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
context.Response.ClearContent();
context.Response.ContentType = "image/Jpeg";
context.Response.BinaryWrite(ms.GetBuffer());
ms.Close();
ms = null;
image.Dispose();
image = null;
}
#endregion
#region生成随机字符码
publicstring CreateVerifyCode(int codeLen)
{
if (codeLen == 0)
{
codeLen = Length;
}
string[] arr = CodeSerial.Split(',');
string code = "";
int randValue = -1;
Random rand = newRandom(unchecked((int)DateTime.Now.Ticks));
for (int i = 0; i < codeLen; i++)
{
randValue = rand.Next(0, arr.Length - 1);
code += arr[randValue];
}
return code;
}
publicstring CreateVerifyCode()
{
return CreateVerifyCode(0);
}
#endregion
}
2.VerifyCodes.aspx.cs代码（只要一个Page_Load事件其余的什么也没有了）
Page_Load事件：
VerifyCode v = newVerifyCode();
string code = v.CreateVerifyCode(4);//验证码长度
v.CreateImageOnPage(code, this.Context);
Session["ver"] = code;
3.Verify.aspx代码
<div>
<img id="imgVerify" alt="看不清？点击更换" onclick="this.src=this.src+'?'" src="VerifyCodes.aspx?"/><br/>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button"/>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label></div>
4.Verify.aspx.cs代码：
protectedvoid Button1_Click(object sender, EventArgs e)
{
if (TextBox1.Text == Session["ver"].ToString())
{
this.Label1.Text = "OKKKKKKKKK";
}
else
{
this.Label1.Text = "Error";
}
}
