C # generates a complex validation code, background random, random font, Chinese and English digital random

Last Update:2018-07-24 Source: Internet

Author: User

Tags alphanumeric characters

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1, set up a website, add a page valitionno.aspx, and Default.aspx, create a new folder images. As shown in the figure:

2, in the Images folder to add the following 5 pictures: bg_0.jpg,bg_1.jpg,bg_2.jpg,bg_3.jpg,bg_4.jpg

Bg_0.jpg

Bg_1.jpg

Bg_2.jpg

Bg_3.jpg

Bg_4.jpg

3, valitionno.aspx not put any control, the code is as follows:

<%@ Page language= "C #" autoeventwireup= "true" codefile= "ValitionNo.aspx.cs" inherits= "Guestbook_valitionno"%>

<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">

<title> Untitled Page </title>
<body>
<form id= "Form1" runat= "Server" >
<div>

</div>
</form>
</body>

4, double-click the page valitionno.aspx into the ValitionNo.aspx.cs page, as follows to fill the code:

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;
Using System.Web.UI.WebControls.WebParts;
Using System.Web.UI.HtmlControls;
Using System.Drawing.Imaging;
Using System.Drawing.Drawing2D;
Using System.Drawing;

public partial class GuestBook_ValitionNo:System.Web.UI.Page
{
protected void Page_Load (object sender, EventArgs e)
{
Random rd = new Random (); Create a random Number object

The following 4 lines produce a string consisting of 6 letters and numbers
String str = "ABCDEFGHIJKLMNOPQRSTURWXYZ0123456789 imagination is infinite";
String Yanzheng = "";
for (int i = 0; i < 6; i++)
{
Yanzheng = Yanzheng + str. Substring (Rd. Next (42), 1);
}
Verify code values are stored in the session for comparison
session["Yanzheng"] = Yanzheng;

The following three sentences, by randomly looking for an existing image to produce a canvas bitmap
String bgfilepath = Server.MapPath ("./images/bg_" + new Random (). Next (5) + ". jpg");//randomly find an image
System.Drawing.Image imgobj = System.Drawing.Image.FromFile (Bgfilepath);
Bitmap Newbitmap = new Bitmap (imgobj, 290, 80);//Create Bitmap Object

Graphics g = graphics.fromimage (Newbitmap);//Create a drawing surface from a bitmap object created above
SolidBrush brush = new SolidBrush (color.blue);//Set Brush color

Defines an array containing 10 fonts
String[] Ziti ={"Arial", "Verdana", "Comic Sans MS", "Impact", "Haettenschweiler", "Lucida Sans Unicode", "Garamond", "Co Urier New "," Book Antiqua "," Arial Narrow "};

By looping, drawing each character,
for (int a = 0; a < Yanzheng. Length; a++)
{
Font textfont = new Font (ZITI[RD. Next (9)], fontstyle.bold);//font random, font size 30, bold
Draws one character at a time, sets the font format, the brush color, the character relative to the canvas's x-coordinate, and the character relative to the canvas's y-coordinate
g.DrawString (Yanzheng. Substring (A, 1), Textfont, brush, + A * 36, 20);
}

Save the picture of the picture into the output stream
Newbitmap.save (Response.outputstream, imageformat.gif);

}
}

5, add a text box in the Default.aspx, Picture button, label label and Normal button, ImageButton picture path is ~/valitionno.aspx, not a picture. The code is as follows:

<%@ Page language= "C #" autoeventwireup= "true" codefile= "Default.aspx.cs" inherits= "_default"%>

<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">

<title> Untitled Page </title>
<body>
<form id= "Form1" runat= "Server" >
<div>
Verification code: <asp:textbox id= "TextBox1" runat= "Server" width= "117px" ></asp:TextBox>
<asp:imagebutton id= "ImageButton1" runat= "Server" imageurl= "~/valitionno.aspx"/>
<asp:linkbutton id= "LinkButton1" runat= "Server" causesvalidation= "False" > Change to a </asp:linkbutton><br/ >
<asp:label id= "Label1" runat= "Server" forecolor= "Red" ></asp:label><br/>
<asp:button id= "Button2" runat= "Server" text= "OK" onclick= "button2_click"/></div>
</form>
</body>

6, in the Default.aspx.cs code is as follows:

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;

public partial class _default:system.web.ui.page
{
protected void Page_Load (object sender, EventArgs e)
{

}
protected void button2_click (object sender, EventArgs e)
{
if (session["Yanzheng"]!= null && textbox1.text!= session["Yanzheng"]. ToString ())
{
Label1.Text = "Authentication code error. ";
Return
}
Else
{
Label1.Text = "Verify code is correct. ";
}
}
}

7, the operating effect is as follows:

If the point verification code picture or point to change a button, you can make the verification code randomly changed, the background random change, the number of alphanumeric characters randomly changed.

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

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