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Message Board-a login page (with verification code)

Source: Internet
Author: User
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<Body>
<Form ID = "form1" runat = "server">
<Div>
<Center>
<Table border = "1" cellpadding = "0" cellspacing = "0">
<Tr>
<TD colspan = "2" style = "color: # ffffff; Background-color: #669900; Height: 32px">
<Span style = "font-size: 24pt">
Login
</Span>
</TD>
</Tr>
<Tr>
<TD> User name: </TD>
<TD>
<Asp: textbox id = "unametextbox" runat = "server"> </ASP: textbox>
</TD>
</Tr>
<Tr>
<TD>
Password & nbsp code:
</TD>
<TD>
<Asp: textbox id = "passwordtextbox" runat = "server" textmode = "password"> </ASP: textbox>
</TD>
</Tr>
<Tr>
<TD>
Image Verification:
</TD>
<TD align = "Left">
<Asp: textbox id = "validatetextbox" runat = "server" width = "71px" Height = "25px"> </ASP: textbox>
<Asp: imagebutton id = "validateimagebutton" runat = "server"/>
</TD>
</Tr>
<Tr>
<TD colspan = "2">
<Asp: Label id = "msglabel" runat = "server" forecolor = "red" font-size = "small"> </ASP: Label>
</TD>
</Tr>
<Tr>
<TD colspan = "2">
<Asp: button id = "landbutton" runat = "server" text = "login" onclick = "landbutton_click"/>
</TD>
</Tr>
</Table>
</Center>
</Div>
</Form>
</Body>

BackgroundCode:

Public partial class login: system. Web. UI. Page
{
Protected void page_load (Object sender, eventargs E)
{
This. validateimagebutton. Imageurl="Image. aspx";
}
Protected void landbutton_click (Object sender, eventargs E)
{
If (this. unametextbox. Text = "") | (this. passwordtextbox. Text = ""))
{
Msglabel. Text = "the user name and password cannot be blank! ";
}
Else
{
Sqlconnection con = dB. createconnection ();
Con. open ();
String strsql = "select upass from login where uname = '" + this. unametextbox. Text + "'";
Sqlcommand cmd = new sqlcommand (strsql, con );
Dataset DS = new dataset ();
Sqldataadapter da = new sqldataadapter (strsql, con );
Da. Fill (DS, "mytable ");

Try
{
If (this. passwordtextbox. Text =DS. Tables [0]. Rows [0]. itemarray [0]. tostring (). Trim () )
{
String curuser = This. unametextbox. text;
Session ["uname"] = This. unametextbox. Text. Trim ();
String AA = This. validatetextbox. Text. tostring ();
If (AA = convert. tostring ( Session ["image"] ) | AA = convert. tostring ( Session ["image"] ). Tolower ())
{
Response. Redirect (" Message. aspx ");
}
Else
{
Response. Write ("<SCRIPT> alert ('verification code is incorrect. Please enter it again! ') </SCRIPT>" );
}
}
Else
{
Msglabel. Text = "incorrect user name or password! ";
}
}
Catch
{
Msglabel. Text = "Sorry! The user name you entered does not exist! ";
}
Con. Close ();
}
}
}

Verification Code production page:
First, create a new page image. aspx. You only need to write background code for this page. The Code is as follows:

Using system. Web. UI;
Using system. Web. UI. webcontrols;
Using system. Web. UI. webcontrols. webparts;
Using system. Web. UI. htmlcontrols;
Using system. IO;
Using system. drawing;

Public partial class image: system. Web. UI. Page
{
Protected void page_load (Object sender, eventargs E)
{
// Generate verification Image
This. genimg (this.Gencode(4 ));

// Store the verification code in the session for verification as needed
Session ["image"]= This.Gencode(4 );
}

// any four verification codes
private string gencode (INT p_num)
{< br> string [] source = {" 0 "," 1 "," 2 ", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C ", "D", "E", "F", "g",
"g", "H", "I", "g", "K ", "L", "M", "n", "O", "P", "Q", "r", "S", "T", "U ", "V", "W", "X", "Y", "Z" };< br> string code = "";
random RD = new random ();

For (INT I = 0; I <p_num; I ++)
{
Code + = source [Rd. Next (0, source. length)];
}

Return code;
}

// Produce images
Private voidGenimg(String p_code)
{
// Define a canvas
BitmapMypalette = new Bitmap (60, 20 );

// Define the drawing instance on the drawing board
Graphics GH = graphics.Fromimage(Mypalette );

// Define a rectangle
Rectangle rc = new rectangle (0, 0, 60, 20 );

// Fill the rectangle
GH.Fillrectangle(New solidbrush (color.Blue), RC );

// Draw a string in the rectangle
Gh.Drawstring(P_code, New font ("", 16), new solidbrush (color. White), RC );

// Display the image
Mypalette.Save(Response. outputstream, system. Drawing. imaging. imageformat.JPEG);

Gh.Dispose();
Mypalette.Dispose();

}
}

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.

Related Keywords:
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