Webform (10)-image watermark, image verification code, and webform watermark

Webform (10)-image watermark, image verification code, and webform watermark

Both of them need to introduce the namespace: using System. Drawing;

I. Image Watermark

Foreground Photoshuiyin. aspx code:

<Div> <asp: FileUpload ID = "FileUpload1" runat = "server"/> <asp: button ID = "Button1" runat = "server" Text = "Upload"/> <br/> <asp: image ID = "Image1" runat = "server"/> </div>

Background Photoshuiyin. aspx. cs code:

Protected void Page_Load (object sender, EventArgs e) {Button1.Click + = button#click;} void button#click (object sender, EventArgs e) {// 1. Create the canvas System. drawing. image img = System. drawing. image. fromStream (FileUpload1.FileContent); Graphics g = Graphics. fromImage (img); // watermark style: Draw Something string a = "http://www.itnba.com"; // Font, size Font f = new Font ("", 30 ); // Color Brush B = new SolidBrush (Color. red); // 0, 0 -- start to draw the watermark position g. drawString (a, f, B, 0, 0); // save path string path = "images/" + FileUpload1.FileName; img. save (Server. mapPath (path); // display Image1.ImageUrl = path in the image control ;}

Effect display:

 

 

 

Ii. Image Verification Code

Foreground Photoyanzhengma. aspx code:

<Form id = "form1" runat = "server"> <div> Username: <asp: TextBox ID = "TextBox1" runat = "server"> </asp: textBox> <br/> password: <asp: TextBox ID = "TextBox2" runat = "server"> </asp: TextBox> <br/> Verification Code: <asp: textBox ID = "TextBox3" runat = "server"> </asp: TextBox> <asp: Image ID = "Image1" runat = "server" ImageUrl = "YZM. aspx "/> <asp: Label ID =" Label1 "runat =" server "Text =" Label "> </asp: Label> <br/> <asp: button ID = "Button1" runat = "se Rver "Text =" Button "/> </div> </form> </body> 

Protected void Page_Load (object sender, EventArgs e) {Random r = new Random (); string aaa = "Random"; // generate the canvas Bitmap img = new Bitmap (80, 30); // canvas background Color generic combination List <Color> Clist = new List <Color> (); Clist. add (Color. yellow); Clist. add (Color. green); Clist. add (Color. blue); Clist. add (Color. aqua); Clist. add (Color. orange); Clist. add (Color. pink); Graphics g = Graphics. fromImage (img); g. fillRectangle (new SolidBrush (Clist [r. next (0, Clist. count)]), 0, 0, 80, 30); // randomly generate the displayed verification code combination string str = ""; for (int I = 0; I <4; I ++) {str + = aaa. substring (r. next (0, aaa. length), 1);} Session ["YZM"] = str; Font f = new Font ("", 20); Brush B = new SolidBrush (Color. red); // generate g. drawString (str, f, B, 10, 0); // Add interference line for (int I = 0; I <r. next (6, 20); I ++) {Brush bb = new SolidBrush (Clist [r. next (0, Clist. count)]); Pen p = new Pen (bb, 1); g. drawLine (p, r. next (0, 80), r. next (0, 30), r. next (0, 80), r. next (0, 30);} // save img. save (Response. outputStream, System. drawing. imaging. imageFormat. jpeg); Response. end ();}
Effect display: