Asp.net generate Verification Code

Using system;
Using system. Data;
Using system. configuration;
Using system. collections;
Using system. Web;
Using system. IO;
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;
Using system. Drawing. drawing2d;
Using system. Drawing. imaging;

Namespace ASPnet. wzh. shopdonet
{
Public partial class getcode: system. Web. UI. Page
{
Private bitmap validateimage;
Private graphics g;
Protected void page_load (Object sender, eventargs E)
{
If (! Ispostback)
{
String vnum = makevalidatecode ();
Session ["getcode"] = vnum;
Validatecode (vnum );
}
}

Public void validatecode (string vnum)
{
Validateimage = new Bitmap (35, 12, pixelformat. format24bpprgb );
G = graphics. fromimage (validateimage );

G. drawstring (vnum, new font ("", 10), new solidbrush (color. White), new pointf (0, 0 ));
G. fillrectangle (New lineargradientbrush (new point (0, 0), new point (110, 20), color. fromargb (1, 138,238,238,255), color. fromargb (38,238,238,255), 0, 0,120, 30 );
G. Save ();
Memorystream MS = new memorystream ();
Validateimage. Save (MS, system. Drawing. imaging. imageformat. GIF );
Response. clearcontent ();
Response. contenttype = "image/GIF ";
Response. binarywrite (Ms. toarray ());
Response. End ();
}

string makevalidatecode ()
{< br> char [] S = new char [] {'0', '1', '2', '3 ', '4', '5', '6', '7', '8', '9'};
string num = "";
random r = new random ();
for (INT I = 0; I <4; I ++)
{< br> num + = s [R. next (0, S. length)]. tostring ();
}< br> return num;
}< BR >}

}

 

In addition, add the content where the verification code needs to be displayed.

<Asp: Image id = "imggetcode" runat = "server" imageurl = "getcode. aspx"/>