c#-webform-★ make picture Verification code ★

<div>        <asp:textbox id= "TextBox1" runat= "Server" ></asp:TextBox> <%--textbox-wait for input verification code--% >        <asp:image id= "Image1" runat= "Server"/> <%--image-show captcha picture--%>        <asp:button id= "Button1" runat= "Server" text= "Commit Validation"/> <%--button-submit for validation--%> <asp:label        id= "Label1" runat= "Server" text= "Verify ..." ></asp:Label> <%--label-Show validation results--%>    </div>

At this point the captcha is empty and nothing is displayed.

Steps:

One, to the CAPTCHA picture control plus a connection, this connection is an. aspx Web page, this page does not need the foreground, only need to open the background to do a verification code image display can be

<asp:image id= "Image1" runat= "Server" imageurl= "yzm.aspx"/>

Second, in the yzm.aspx backstage to make a simple verification code

Using system;using system.collections.generic;using system.linq;using system.web;using System.Web.UI;using System.web.ui.webcontrols;using System.drawing;public partial class yzm:system.web.ui.page{protected void Page_Load (        Object sender, EventArgs e) {Random r = new Random ();        Make "Bitmap" (Specify a rectangular area of length and width) Bitmap img = new Bitmap (60,30);        Ready to make-//set canvas Graphics g = Graphics.fromimage (IMG);        Output string all = "abcdefghijklmnopqrstuvwsyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";        string s = ""; for (int i = 1; I <= 4; i++) {s + = all. Substring (R.next (All).        Length), 1);        }//String fonts font f=new font ("Microsoft Jas Black", 16);        The color of the font Brush b=new SolidBrush (color.red);        Starting position PointF p=new PointF (3,3);        Making-g.drawstring (S, F, B, p); To save (save to stream) img.        Save (response.outputstream,system.drawing.imaging.imageformat.png);    Response.End (); }} 

Using system;using system.collections.generic;using system.linq;using system.web;using System.Web.UI;using System.web.ui.webcontrols;using System.drawing;public partial class yzm:system.web.ui.page{protected void Page_Load (        Object sender, EventArgs e) {Random r = new Random ();        Make "Bitmap" (Specify a rectangular area of length and width) Bitmap img = new Bitmap (60,30);        Ready to make-//set canvas Graphics g = Graphics.fromimage (IMG);        Output string all = "abcdefghijklmnopqrstuvwsyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";        string s = ""; for (int i = 1; I <= 4; i++) {s + = all. Substring (R.next (All).        Length), 1);        }//String fonts font f=new font ("Microsoft Jas Black", 16);        The color of the font Brush b=new SolidBrush (color.red);        Starting position PointF p=new PointF (3,3);        Making-g.drawstring (S, F, B, p); To save (save to stream) img.        Save (response.outputstream,system.drawing.imaging.imageformat.png);    Response.End (); }} 

Effect:

Third, set < submit verification > function

Using system;using system.collections.generic;using system.linq;using system.web;using System.Web.UI;using System.web.ui.webcontrols;public partial class _default:system.web.ui.page{    protected void Page_Load (object sender, EventArgs e)    {        btn_verification. Click+=btn_verification_click;    }    < Submit validation > button click event    void Btn_verification_click (object sender, EventArgs e)    {        string s1 = Txt_ Useryzm.text;        String s2 = session["YZM"]. ToString ();        if (S1. ToUpper () = = S2. ToUpper ())        {            Label1.Text = "Verified successfully! ";        }        else        {            Label1.Text = "Validation failed! ";        }    }}

Using system;using system.collections.generic;using system.linq;using system.web;using System.Web.UI;using System.web.ui.webcontrols;public partial class _default:system.web.ui.page{    protected void Page_Load (object sender, EventArgs e)    {        btn_verification. Click+=btn_verification_click;    }    < Submit validation > button click event    void Btn_verification_click (object sender, EventArgs e)    {        string s1 = Txt_ Useryzm.text;        String s2 = session["YZM"]. ToString ();        if (S1. ToUpper () = = S2. ToUpper ())        {            Label1.Text = "Verified successfully! ";        }        else        {            Label1.Text = "Validation failed! ";        }    }}

Effect:

Verify that automatic refresh is successful

Four, set the Click Verification Code switch Verification code-front JS

<script type= "Text/javascript" >    var a = 0;    document.getElementById ("Image1"). onclick = function () {        this.setattribute ("src", "yzm.aspx?id=" + a);        a++;    } </script>

<script type= "Text/javascript" >    var a = 0;    document.getElementById ("Image1"). onclick = function () {        this.setattribute ("src", "yzm.aspx?id=" + a);        a++;    } </script>

Set the captcha background color and the interference line fills the rectangular area: FillRectangle

Sets the background color        g.fillrectangle (New SolidBrush (Clist[r.next (clist. Count)]), 0, 0, (+);        Set the interference line for        (int i = 1; i <=; i++)        {            //random colors color            c_line = Clist[r.next (0, CList. Count)];            Interference line color, thickness            Pen p_line = new Pen (new SolidBrush (C_line), R.next (1, 5));            Draw the interference line            G.drawline (P_line, New PointF (r.next (0, 0), R.next (0,)), New PointF (R.next (0,))        

Sets the background color        g.fillrectangle (New SolidBrush (Clist[r.next (clist. Count)]), 0, 0, (+);        Set the interference line for        (int i = 1; i <=; i++)        {            //random colors color            c_line = Clist[r.next (0, CList. Count)];            Interference line color, thickness            Pen p_line = new Pen (new SolidBrush (C_line), R.next (1, 5));            Draw the interference line            G.drawline (P_line, New PointF (r.next (0, 0), R.next (0,)), New PointF (R.next (0,))        

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Verification Code picture Background code:

Using system;using system.collections.generic;using system.linq;using system.web;using System.Web.UI;using System.web.ui.webcontrols;using System.drawing;public partial class yzm:system.web.ui.page{protected void Page_Load (        Object sender, EventArgs e) {Random r = new Random ();        Color Set list<color> clist = new list<color> (); CList.        ADD (Color.yellow); CList.        ADD (Color.pink); CList.        ADD (Color.Blue); CList.        ADD (Color.green); CList.        ADD (Color.orange); CList.        ADD (Color.Black);        Make "Bitmap" (Specify a rectangular area of length and width) Bitmap img = new Bitmap (70, 30);        Set Canvas Graphics g = Graphics.fromimage (IMG); Sets the background color g.fillrectangle (new SolidBrush (Clist[r.next (clist.        Count)]), 0, 0, 70, 30); Set the interference line for (int i = 1; i <=; i++) {//random colors color c_line = Clist[r.next (0, CList .            Count)]; Interference line color, thickness Pen p_line = new Pen (new SolidBrush (C_line), R.next (1, 5));        Draw interference lines G.drawline (P_line, New PointF (R.next (0, 30), R.next (0,)), New PointF (R.next (0,), R.next (0,));        }//output string all = "abcdefghijklmnopqrstuvwsyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";        string s = ""; for (int i = 1; I <= 4; i++) {s + = all. Substring (R.next (All).        Length), 1);        }//generated validation is placed into global variables session["YZM"] = s;        Font of the string fonts f = new Font ("Microsoft Jas Black", 16);        The color of the font Brush b = new SolidBrush (color.red);        Starting position PointF p = new PointF (3, 3);        Making-g.drawstring (S, F, B, p); To save (save to stream) img.        Save (Response.outputstream, System.Drawing.Imaging.ImageFormat.Png);    Response.End (); }}

Using system;using system.collections.generic;using system.linq;using system.web;using System.Web.UI;using System.web.ui.webcontrols;using System.drawing;public partial class yzm:system.web.ui.page{protected void Page_Load (        Object sender, EventArgs e) {Random r = new Random ();        Color Set list<color> clist = new list<color> (); CList.        ADD (Color.yellow); CList.        ADD (Color.pink); CList.        ADD (Color.Blue); CList.        ADD (Color.green); CList.        ADD (Color.orange); CList.        ADD (Color.Black);        Make "Bitmap" (Specify a rectangular area of length and width) Bitmap img = new Bitmap (70, 30);        Set Canvas Graphics g = Graphics.fromimage (IMG); Sets the background color g.fillrectangle (new SolidBrush (Clist[r.next (clist.        Count)]), 0, 0, 70, 30); Set the interference line for (int i = 1; i <=; i++) {//random colors color c_line = Clist[r.next (0, CList .            Count)]; Interference line color, thickness Pen p_line = new Pen (new SolidBrush (C_line), R.next (1, 5));        Draw interference lines G.drawline (P_line, New PointF (R.next (0, 30), R.next (0,)), New PointF (R.next (0,), R.next (0,));        }//output string all = "abcdefghijklmnopqrstuvwsyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";        string s = ""; for (int i = 1; I <= 4; i++) {s + = all. Substring (R.next (All).        Length), 1);        }//generated validation is placed into global variables session["YZM"] = s;        Font of the string fonts f = new Font ("Microsoft Jas Black", 16);        The color of the font Brush b = new SolidBrush (color.red);        Starting position PointF p = new PointF (3, 3);        Making-g.drawstring (S, F, B, p); To save (save to stream) img.        Save (Response.outputstream, System.Drawing.Imaging.ImageFormat.Png);    Response.End (); }}

c#-webform-★ make picture Verification code ★