Friday, December 25, 2015

Create CAPTCHA in ASP.NET C#

In this article going to explain how to create CAPTCHA in asp.net c#.

 Before creating the captcha first we want to know why we using captcha?

Captcha code ids kind of image is used to validate client browser window really has a human typing into it or not Or simply say captcha is only be read by human not by robots.( Robots ia a kind of program that automativally submit the data to the website) and when we want to prevent it we use the captcha.

Now Lets move with creating captcha in asp.net c#

Firstly Create a "GenerateCaptcha.aspx" page

 code of GenerateCaptcha.aspx"
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GenerateCaptcha.aspx.cs" Inherits="GenerateCaptcha" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
   
    </div>
    </form>
</body>
</html>

code of GenerateCaptcha.aspx.cs"

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
public partial class GenerateCaptcha : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Response.Clear();
        int height = 30;
        int width = 100;
        Bitmap bmp = new Bitmap(width, height);
        RectangleF rectf = new RectangleF(10, 5, 0, 0);
        Graphics g = Graphics.FromImage(bmp);
        g.Clear(Color.White);
        g.SmoothingMode = SmoothingMode.AntiAlias;
        g.InterpolationMode = InterpolationMode.HighQualityBicubic;
        g.PixelOffsetMode = PixelOffsetMode.HighQuality;
        g.DrawString(Session["captcha"].ToString(), new Font("Segoe UI", 15, FontStyle.Strikeout), Brushes.Red, rectf);
        g.DrawRectangle(new Pen(Color.Bisque), 1, 1, width - 2, height - 2);
        g.Flush();
        Response.ContentType = "image/jpeg";
        bmp.Save(Response.OutputStream, ImageFormat.Jpeg);
        g.Dispose();
        bmp.Dispose();
    }
}

Now Create another Default.aspx page

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
       <form id="form1" runat="server">
    <div>
       <asp:Panel ID="pnlCheckCaptcha" runat="server" GroupingText="<b>Check Captcha"></b>&nbsp;<table>
       <tr>
       <td>Write Catcha Here</td>
       <td><asp:TextBox ID="txtCaptcha" runat="server"></asp:TextBox></td>
       </tr>
       <tr>
       <td><asp:Image ID="imgCaptcha" runat="server" /></td>
       <td>
        <asp:Button ID="btnRefresh" runat="server" Text="Refresh" OnClick="btnRefresh_Click" />
       </td>
       </tr>
       <tr>
       <td colspan="2" align="center"><asp:Button ID="btnchekcatcha" runat="server"
               Text="Check" onclick="btnchekcatcha_Click"/>
               <asp:Label ID="lblmsg" runat="server" ForeColor="Red"></asp:Label>
               </td>
       </tr>
       </table>
       </asp:Panel>
    </div>
    </form>
</body>
</html>

Default.aspx.cs page 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;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Text;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        try
        {
            if (!IsPostBack)
            {
                GetCapctha();
            }
        }
        catch (Exception ex)
        {
            lblmsg.Text = ex.Message.ToString();
        }
    }
    void GetCapctha()
    {
        try
        {
            Random random = new Random();
            string combination = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
            StringBuilder captcha = new StringBuilder();
            for (int i = 0; i < 6; i++)
                captcha.Append(combination[random.Next(combination.Length)]);
            Session["captcha"] = captcha.ToString();
            imgCaptcha.ImageUrl = "GenerateCaptcha.aspx?" + DateTime.Now.Ticks.ToString();
        }
        catch
        {
            throw;
        }
    }
    protected void btnRefresh_Click(object sender, EventArgs e)
    {
        try
        {
            GetCapctha();
        }
        catch (Exception ex)
        {
            lblmsg.Text = ex.Message.ToString();
        }
    }
   
    protected void btnchekcatcha_Click(object sender, EventArgs e)
    {
        try
        {
            if (Session["captcha"].ToString() != txtCaptcha.Text)
                lblmsg.Text = "Invalid Captcha Code";
            else
                lblmsg.Text = "Valid Captcha Code";
            GetCapctha();
        }
        catch (Exception ex)
        {
            lblmsg.Text = ex.Message.ToString();
        }
    }
}

Output
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Wednesday, December 23, 2015

Dynamically add remove rows in table in ASP.NET using javascript

In this article I am going to explain how to add and delete row of Table in ASP. net c# using JavaScript and use their value in c#.

 Add and delete row in table JavaScript
<script type="text/javascript">
        function AddNewRecord() {
            var grd = document.getElementById("gvEmp");
            var lengthgrd = grd.rows.length - 1;
        
              //validation check
            if (lengthgrd >= 1) {
 
                var Name = grd.rows[lengthgrd].cells[0].getElementsByTagName('input')[0].value;
                if (Name.trim() == "") {
                    alert("Please Fill Name.");
                    return false;
                }
              
                var Gender = grd.rows[lengthgrd].cells[2].getElementsByTagName('select')[0].value;
                if (Gender.trim() == "Select Gender") {
                    alert("Please Select Gender.");
                    return false;
                }
            }
            var tbod = grd.rows[0].parentNode;
            var newRow = grd.rows[grd.rows.length - 1].cloneNode(true);
            tbod.appendChild(newRow);
            addvalue();//new row add with empty value
        }
 
 
        function addvalue() {
            var grd = document.getElementById("gvEmp");
            var no = grd.rows.length - 1
            grd.rows[no].cells[0].getElementsByTagName('input')[0].value = "";
            grd.rows[no].cells[1].getElementsByTagName('input')[0].value = "";
        }
 
 
        //delete row
        function deleteRow(row) {
            var i = row.parentNode.parentNode.rowIndex;
            var x = document.getElementById("gvEmp");
            var xx = x.rows.length - 1;
 
            if (xx != 1) {
                document.getElementById("gvEmp").deleteRow(i);
            }
            if (xx == 1) {
                x.rows[1].cells[0].getElementsByTagName('input')[0].value = "";
                x.rows[1].cells[1].getElementsByTagName('input')[0].value = "";
                x.rows[1].cells[2].getElementsByTagName('select')[0].value = "Select Gender";
            }
        }
    </script> 

aspx code
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
    <script type="text/javascript">
        function AddNewRecord() {
            var grd = document.getElementById("gvEmp");
            var lengthgrd = grd.rows.length - 1;
        
              //validation check
            if (lengthgrd >= 1) {
 
                var Name = grd.rows[lengthgrd].cells[0].getElementsByTagName('input')[0].value;
                if (Name.trim() == "") {
                    alert("Please Fill Name.");
                    return false;
                }
              
                var Gender = grd.rows[lengthgrd].cells[2].getElementsByTagName('select')[0].value;
                if (Gender.trim() == "Select Gender") {
                    alert("Please Select Gender.");
                    return false;
                }
            }
            var tbod = grd.rows[0].parentNode;
            var newRow = grd.rows[grd.rows.length - 1].cloneNode(true);
            tbod.appendChild(newRow);
            addvalue();//new row add with empty value
        }
 
 
        function addvalue() {
            var grd = document.getElementById("gvEmp");
            var no = grd.rows.length - 1
            grd.rows[no].cells[0].getElementsByTagName('input')[0].value = "";
            grd.rows[no].cells[1].getElementsByTagName('input')[0].value = "";
        }
 
 
        //delete row
        function deleteRow(row) {
            var i = row.parentNode.parentNode.rowIndex;
            var x = document.getElementById("gvEmp");
            var xx = x.rows.length - 1;
 
            if (xx != 1) {
                document.getElementById("gvEmp").deleteRow(i);
            }
            if (xx == 1) {
                x.rows[1].cells[0].getElementsByTagName('input')[0].value = "";
                x.rows[1].cells[1].getElementsByTagName('input')[0].value = "";
                x.rows[1].cells[2].getElementsByTagName('select')[0].value = "Select Gender";
            }
        }
 
 
        //assign value into textbox
 
        function AssignGender(row) {
 
            var rowvalue = $(row).closest('tr').index();
            var grd = document.getElementById("gvEmp");
            var Gender = grd.rows[rowvalue].cells[2].getElementsByTagName('select')[0].value;
            document.getElementById("txtGender").value = Gender;
           
        }
 
    </script>
  
</head>
<body>
    <form id="form1" runat="server">
  <fieldset style="border:1px solid #cccccc; position:relative;">
<legend style="font-size:14px; font-weight:bold; color:#395b77; margin-left:4px; padding:0px 5px;">Employee Detail</legend>
 
 
<input type="button" id="Add Employee" value="Add More Row" onclick="AddNewRecord()" class="btnaddmor" />
 
<table id="gvEmp" border="1" runat="server">
 
<tr>
<td class="hed">Name</td>
<td class="hed">Age</td>
<td class="hed">Gender</td>
<td class="hed">Delete</td>
</tr>
 
<tr>
<td>
<asp:TextBox ID="txtName" runat="server" MaxLength="50" onkeypress="return ValidateText(event)" onpaste="return false" >
</asp:TextBox>
</td>
 
<td>
<asp:TextBox ID="txtAge" runat="server" MaxLength="2" ></asp:TextBox>
</td>
 
 
 
<td align="center">
<asp:DropDownList ID="ddlGender" runat="server" onchange="AssignGender(this)">
<asp:ListItem>Select Gender</asp:ListItem>
<asp:ListItem>Male</asp:ListItem>
<asp:ListItem>Female</asp:ListItem>
</asp:DropDownList>
<asp:TextBox ID="txtGender" runat="server" style="display:none;"></asp:TextBox>
</td>
 
 
<td align="center"><input type="button" id="delbutton" value="Delete" onclick="deleteRow(this)" class="btndel" /></td>
</tr>
</table>
 
<asp:Button ID="btnGettableValue" Text="Get Value" runat="server"
          onclick="btnGettableValue_Click" />
      <asp:GridView ID="GridView1" runat="server">
      </asp:GridView>
</fieldset>
    </form>
</body>
</html>

cs code


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
 
    }
    protected void btnGettableValue_Click(object sender, EventArgs e)
    {
 
        // get all aspx table value in c#
        DataTable dt = new DataTable();
        dt.Columns.Add("Name");
        dt.Columns.Add("Age");
        dt.Columns.Add("Gender");
        int GridRow = gvEmp.Rows.Count;
        if (GridRow > 0)
        {
            TextBox Name = (TextBox)gvEmp.Rows[0].FindControl("txtName");
            TextBox Age = (TextBox)gvEmp.Rows[0].FindControl("txtAge");
            TextBox Gender = (TextBox)gvEmp.Rows[0].FindControl("txtGender");
            DropDownList dGender = (DropDownList)gvEmp.Rows[0].FindControl("ddlGender");
 
 
            string[] SplitName = Name.Text.Split(',');
            string[] SplitAge = Age.Text.Split(',');
            string[] SplitGender = Gender.Text.Split(',');
 
            for (int iCount = 0; iCount < SplitName.Length; iCount++)
            {
                if (!string.IsNullOrEmpty(SplitName[iCount].Trim()))
                {
 
                    int updatevalue = iCount;
                    ++updatevalue;
                    DataRow rr = dt.NewRow();
                    rr["Name"] = SplitName[iCount];
                    rr["Age"] = SplitAge[iCount];
                    rr["Gender"] = SplitGender[iCount];
                    dt.Rows.Add(rr);
                }
            }
 
 
            //empty table rows
            Name.Text = "";
            Age.Text = "";
            Gender.Text = "";
            dGender.SelectedIndex = 0;
        }
 
 
        // show table value in gridview
        GridView1.DataSource = dt;
        GridView1.DataBind();
 
    }
}
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