How to implement asp.net to create bitmap and generate verification picture class
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
