Shulou(Shulou.com)06/03 Report--

This article introduces the relevant knowledge of "how to create bitmaps to generate and verify picture classes in asp.net". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

The copy code is as follows:

Public void ProcessRequest (HttpContext context)

{

Context.Response.ContentType = "image/jpeg"

/ / create a bitmap and specify the width and height of the frame

Using (Image img=new Bitmap (800.25))

{

/ / create a painter object and draw a string in the img object

Using (Graphics g=Graphics.FromImage (img))

{

/ / sets the background color of the bitmap. The default is black.

G.Clear (Color.White)

/ / set the width and height of the CAPTCHA. Img.Width-1 and img.Height-1 mainly cover the border with the background color.

G.DrawRectangle (Pens.Black, 0,0, img.Width-1, img.Height-1)

/ / transfer 100 noises, painter objects, bitmap objects

DrawPoint (100g, img)

/ / draw a string of 4 CAPTCHA codes

String vcode=GetCode (4); / / vcode can be assigned to Cookie here

G.DrawString (vcode

New Font ("Arial", 14, FontStyle.Strikeout | FontStyle.Strikeout), / / FontStyle font style, multiple styles are required | Line

Brushes.Black

New RectangleF (r.Next (20), r.Next (7), img.Width, img.Height))

Img.Save (context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); / / Save the CAPTCHA object, specified in Jpeg format

}

}

}

/ / method of drawing noise

Void DrawPoint (int point,Graphics grecently Image img)

{

For (int I = 0; I < point; iTunes +)

{

Int x = r.Next (img.Width)

Int y = r.Next (img.Width)

G.DrawLine (Pens.Red

New Point (x, y)

New Point (Xerox 2, YF2))

}

}

/ / Random number

Random r = new Random ()

/ / character creation

String GetCode (int point)

{

String txtStr = "ASF2345WE5R9F3HMBCZ455K"; / / the string string here will be converted into an char array, and the Arabic numeral 1 and the lowercase l had better not be written in it, it will be messy.

Char [] charArr = txtStr.ToArray ()

Int num = 0

String code = ""

For (int I = 0; I

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