Copy CodeThe code is as follows:
<%@ Page language= "C #" autoeventwireup= "true" codefile= "Login.aspx.cs" inherits= "Login"%>
<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<title> Untitled Page </title>
<script type= "Text/javascript" >
function Dofresh () {
document.getElementById ("Image1"). src = "verifycode.aspx";
}
</script>
<body>
<form id= "Form1" runat= "Server" >
<div>
<table>
<tr>
<td>
Verification code: <asp:textbox id= "Txtvalidatecode" runat= "Server" ></asp:TextBox>
</td>
<td>
<asp:image id= "Image1" runat= "Server"/>
<a href= "Javascript:dofresh ();" > Can't see clearly?</a>
</td>
</tr>
<tr>
<TD align= "center" colspan= "2" >
<br/>
<asp:literal id= "literrormsg" runat= "Server" ></asp:Literal>
<asp:button id= "btnsubmit" runat= "Server" text= "OK"/>
</td>
</tr>
</table>
</div>
</form>
</body>
Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Web;
Using System.Web.UI;
Using System.Web.UI.WebControls;
public partial class Login:System.Web.UI.Page
{
protected void Page_Load (object sender, EventArgs e)
{
if (! Page.IsPostBack)
{
Image1.imageurl = "verifycode.aspx";
}
}
protected void btnSubmit_Click (object sender, EventArgs e)
{
if (session["Validatecode"]!= null)
{
String outputvalidatecode = session["Validatecode"] as String;
String inputvalidatecode = TxtValidateCode.Text.Trim ();
if (String.Compare (Outputvalidatecode, Inputvalidatecode, True)!= 0)
{
Response.Write (' <script>javascript:alert (' Input validation code Error! ');</script> ");
Literrormsg.text = "The authentication code entered is wrong!" ";
}
Else
{
Response.Write (' <script>javascript:alert (' Input verification code is correct! ');</script> ");
Literrormsg.text = "The authentication code entered is correct!" ";
}
}
}
#region call the following method to implement the client save Cookie Authentication mode
private void Validatemethod ()
{
if (request.cookies["checkcode"] = = null)
{
Literrormsg.text = "Your browser settings have been disabled cookies, you must set the browser to allow the use of cookies to use the system." ";
Literrormsg.visible = true;
Return
}
if (String.Compare (request.cookies["Checkcode"). Value, TextBox1.Text.ToString (). Trim (), True)!= 0)
{
Literrormsg.text = "<font color=red> Sorry, verification code error!" </font> ";
Literrormsg.visible = true;
Return
}
Else
{
Literrormsg.text = "<font color=green> Congratulations, verify code input correct!" </font> ";
Literrormsg.visible = true;
}
}
#endregion
}
Verifycode.aspx for the default generated code
Copy CodeThe code is as follows:
Using System;
Using System.Data;
Using System.Configuration;
Using System.Collections;
Using System.Web;
Using System.Web.Security;
Using System.Web.UI;
Using System.Web.UI.WebControls.WebParts;
Using System.Web.UI.HtmlControls;
Using System.Drawing;
Using System.Drawing.Imaging;
Using System.Drawing.Drawing2D;
Using System.IO;
public partial class VerifyCode:System.Web.UI.Page
{
protected void Page_Load (object sender, EventArgs e)
{
Generatevalidatecode ();
Generateverifyimage (4);//generateverifyimage (int length)
}
#region "No refresh imitation Google waveform distorted color" captcha style 0___generatevalidatecode ()
private void Generatevalidatecode ()
{
This. Length = This.length;
This. FontSize = this.fontsize;
This. Chaos = This.chaos;
This. BackgroundColor = This.backgroundcolor;
This. Chaoscolor = This.chaoscolor;
This. Codeserial = this.codeserial;
This. Colors = this.colors;
This. Fonts = this.fonts;
This. Padding = this.padding;
String vnum = this. Createverifycode (); Take random Code
session["Validatecode"] = Vnum.toupper ()//obtain a CAPTCHA to verify later
This. Createimageonpage (Vnum, this. context); Output picture
Cookie authentication mode, using cookies to take the value of the verification code
RESPONSE.COOKIES.ADD (New HttpCookie ("Checkcode", code. ToUpper ()));
}
#endregion
#region Verification Code Length (the length of the default 4 Authenticode)
int length = 4;
public int Length
{
get {return length;}
set {length = value;}
}
#endregion
#region Authenticode font size (default 40 pixels for distortion to appear, you can modify it yourself)
int fontsize = 22;
public int FontSize
{
get {return fontsize;}
set {fontsize = value;}
}
#endregion
#region Border Supplement (default 1 pixels)
int padding = 2;
public int Padding
{
get {return padding;}
set {padding = value;}
}
#endregion
#region whether to output dryness point (default does not output)
BOOL Chaos = true;
public bool Chaos
{
get {return chaos;}
set {chaos = value;}
}
#endregion
#region the color of the output dryness point (default gray)
Color chaoscolor = Color.lightgray;
Public Color Chaoscolor
{
get {return chaoscolor;}
set {Chaoscolor = value;}
}
#endregion
#region Custom background color (default white)
Color backgroundcolor = Color.White;
Public Color BackgroundColor
{
get {return backgroundcolor;}
set {backgroundcolor = value;}
}
#endregion
#region Custom Random Color array
color[] Colors = {color.black, color.red, Color.darkblue, Color.green, Color.orange, Color.brown, Color.darkcyan, Color. Purple};
Public color[] Colors
{
get {return colors;}
set {colors = value;}
}
#endregion
#region a custom font array
string[] fonts = {"Arial", "Georgia"};
Public string[] Fonts
{
get {return fonts;}
set {fonts = value;}
}
#endregion
#region custom Random code string sequence (separated by commas)
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 ";
public string codeserial
{
get {return codeserial;}
set {codeserial = value;}
}
#endregion
#region Generate waveform Filter effect
Private Const Double PI = 3.1415926535897932384626433832795;
Private Const Double PI2 = 6.283185307179586476925286766559;
<summary>
Sine Wave distorted picture
</summary>
<param name= "srcbmp" > Picture path </param>
<param name= "Bxdir" > If skew is selected as true</param>
<param name= "Nmultvalue" > Waveform amplitude multiples, the greater the degree of distortion of the higher, generally 3</param>
<param name= "Dphase" > Waveform starting phase, value interval [0-2*pi) </param>
<returns></returns>
Public Bitmap twistimage (Bitmap srcbmp, bool Bxdir, double dmultvalue, double dphase)
{
Bitmap destbmp = new Bitmap (srcbmp.width, srcbmp.height);
Fill a bitmap background with white
System.Drawing.Graphics graph = graphics.fromimage (destbmp);
Graph. FillRectangle (New SolidBrush (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);
Get the color of the current point
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 Generate check code picture
Public Bitmap 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 = new Random ();
Add a randomly generated dryness point to the background
if (this. Chaos)
{
Pen pen = new Pen (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;
Validation code characters for random fonts and colors
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);
}
Draw a border border color for Color.gainsboro
G.drawrectangle (New Pen (Color.gainsboro, 0), 0, 0, image. Width-1, image. HEIGHT-1);
G.dispose ();
Generate Waveform (ADD by 51aspx.com)
Image = Twistimage (image, True, 4, 4);
return image;
}
#endregion
#region output the created picture to the page
public void Createimageonpage (string code, HttpContext context)
{
Response.bufferoutput = true; Special attention
Response.Cache.SetExpires (DateTime.Now.AddMilliseconds (-1));//Special attention
Response.Cache.SetCacheability (Httpcacheability.nocache)/special attention
Response.appendheader ("Pragma", "No-cache"); Special attention
MemoryStream ms = new MemoryStream ();
Bitmap image = this. Createimagecode (code);
Image. Save (MS, Imageformat.jpeg);
Response.clearcontent ();
Response.ContentType = "Image/jpeg";
Response.BinaryWrite (Ms. ToArray ());
Response.End ();
Ms. Close ();
ms = NULL;
Image. Dispose ();
image = NULL;
}
#endregion
#region Generate random character codes
public string Createverifycode (int codelen)
{
if (Codelen = 0)
{
Codelen = Length;
}
string[] arr = codeserial.split (', ');
String code = "";
int randvalue =-1;
Random rand = new Random (unchecked (int) DateTime.Now.Ticks));
for (int i = 0; i < Codelen; i++)
{
Randvalue = Rand. Next (0, arr. LENGTH-1);
Code + + Arr[randvalue];
}
return code;
}
public string Createverifycode ()
{
Return Createverifycode (0);
}
#endregion
#region Another authentication code style generateverifyimage (int length)
<summary>
Output the created picture to the page
</summary>
public void generateverifyimage (int nlen)
{
String validatecode = "";//generated Verification code
int nbmpwidth = Getimagewidth (Nlen);
int nbmpheight = Getimageheight ();
System.Drawing.Bitmap bmp = New System.Drawing.Bitmap (nbmpwidth, nbmpheight);
To bend an image
Twistimage (BMP, True, 12, 2);
1. Generate Random background color
int nRed, Ngreen, Nblue; Ternary color of the background
System.Random rd = new Random ((int) System.DateTime.Now.Ticks);
nRed = Rd. Next (255)% 128 + 128;
Ngreen = Rd. Next (255)% 128 + 128;
nblue = Rd. Next (255)% 128 + 128;
2. Fill a bitmap background
System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage (BMP);
Graph. FillRectangle (New SolidBrush (System.Drawing.Color.FromArgb (nRed, Ngreen, Nblue))
, 0
, 0
, Nbmpwidth
, nbmpheight);
3. Draw a disturbing line with a slightly darker color than the background
int nlines = 3;
System.Drawing.Pen Pen = new System.Drawing.Pen (System.Drawing.Color.FromArgb (NRED-17, NGREEN-17, NBLUE-17), 2);
for (int a = 0; a < nlines; a++)
{
int x1 = Rd. Next ()% Nbmpwidth;
int y1 = Rd. Next ()% Nbmpheight;
int x2 = Rd. Next ()% Nbmpwidth;
int y2 = Rd. Next ()% Nbmpheight;
Graph. DrawLine (pen, x1, y1, x2, y2);
}
The character set that you use can be expanded immediately, and you can control the probability of the character appearing
String strcode = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
4. Loop to get the character and draw
for (int i = 0; i < Nlen; i++)
{
int x = (i * + Rd. Next (3));
int y = Rd. Next (4) + 1;
Determine font
System.Drawing.Font font = new System.Drawing.Font ("Courier new",//Text font type
+ Rd. Next ()% 4,//text font size
System.Drawing.FontStyle.Bold);//text font style
char C = strcode[rd. Next (Strcode.length)]; Random Fetch character
Validatecode + + c.tostring ();
Drawing characters
Graph. DrawString (c.tostring (),
Font
New SolidBrush (System.Drawing.Color.FromArgb (nRed-60 + y * 3, nGreen-60 + y * 3, nBlue-40 + y * 3)),
X
y);
}
session["Validatecode"] = Validatecode;
To bend an image
Twistimage (BMP, True, 4, 4);
Response.bufferoutput = true; Special attention
Response.Cache.SetExpires (DateTime.Now.AddMilliseconds (-1));//Special attention
Response.Cache.SetCacheability (Httpcacheability.nocache)/special attention
Response.appendheader ("Pragma", "No-cache"); Special attention
5. Output byte stream
MemoryStream bstream = new MemoryStream ();
Bmp. Save (Bstream, imageformat.jpeg);
Response.clearcontent ();
Response.ContentType = "Image/jpeg";
Response.BinaryWrite (Bstream. ToArray ());
Response.End ();
Bstream. Close ();
Bstream = null;
Bmp. Dispose ();
BMP = NULL;
Graph. Dispose ();
}
<summary>
Get the width of the verification code picture
</summary>
<paramname= "Validatenumlength" > Verification Code length </param>
<returns></returns>
public static int getimagewidth (int validatenumlength)
{
return (int) (validatenumlength + 5);
}
<summary>
Get the height of the verification code
</summary>
<returns></returns>
public static int Getimageheight ()
{
return 25;
}
#endregion
}
