| Reference content is as follows:
Protected void Page_Load (object sender, EventArgs e)
{
This. CreateCheckCodeImage (GenerateCheckCode ());
}
Private string GenerateCheckCode ()
{
Int number;
Char code;
String checkCode = string. Empty; Random radom = new Random (); For (int I = 0; I <6; I ++)
{
Number = radom. Next ();
If (number % 2 = 0)
{
Code = (char) ('0' + (char) (number % 10 ));
}
Else
{
Code = (char) ('A' + (char) (number % 26 ));
}
CheckCode + = code. ToString ();
}
Response. Cookies. Add (new HttpCookie ("CheckCode", checkCode ));
Return checkCode;
} Private void CreateCheckCodeImage (string checkCode)
{
If (checkCode = null | checkCode. Trim () = String. Empty)
{
Return;
}
System. Drawing. Bitmap image = new System. Drawing. Bitmap (int) Math. Ceiling (checkCode. Length * 12.5), 22 );
System. Drawing. Graphics g = System. Drawing. Graphics. FromImage (image );
Try
{
// Generate a random Generator
Random random = new Random (); // Clear the background color of the image
G. Clear (Color. White ); // Draw the background noise line of the image
For (int I = 0; I <25; I ++)
{
Int x1 = random. Next (image. Width );
Int x2 = random. Next (image. Width );
Int y1 = random. Next (image. Height );
Int y2 = random. Next (image. Height ); G. DrawLine (new Pen (Color. GreenYellow), x1, y1, x2, y2 );
} Font font = new System. Drawing. Font ("Verdana", 12, (System. Drawing. FontStyle. Bold | System. Drawing. FontStyle. Italic ));
System. drawing. drawing2D. linearGradientBrush brush = new System. drawing. drawing2D. linearGradientBrush (new Rectangle (0, 0, image. width, image. height), Color. blue, Color. darkRed, 1.2f, true );
G. DrawString (checkCode, font, brush, 2, 2 ); // Foreground noise of the image
For (int I = 0; I <80; I ++)
{
Int x = random. Next (image. Width );
Int y = random. Next (image. Height ); Image. SetPixel (x, y, Color. FromArgb (random. Next ()));
} // Draw the border line of the image
G. DrawRectangle (new Pen (Color. Red), 0, 0, image. Width-1, image. Height-1 ); System. IO. MemoryStream MS = new System. IO. MemoryStream ();
Image. Save (MS, System. Drawing. Imaging. ImageFormat. Gif );
Response. ClearContent ();
Response. ContentType = "image/Gif ";
Response. BinaryWrite (ms. ToArray ());
}
Finally
{
G. Dispose ();
Image. Dispose ();
}
}
<Form id = "form1" runat = "server">
<Div>
<Asp: TextBox runat = "server" ID = "txt"> </asp: TextBox>
<Br/>
<Asp: Button runat = "server" ID = "bt" onclick = "bt_Click" Text = "Submit"/> <asp: label runat = "server" ID = "msg"> </asp: Label>
</Div>
</Form> |
