Here, we will see how to concatenate integers
and string in C#. To do that we take two TextBox for integers and one TextBox
for string and one TextBox for concatenate both integers and string.
Aspx code
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="add.aspx.cs" Inherits="addtextbox.add" %>
<!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>
First:
<asp:TextBox ID="txt1" runat="server"></asp:TextBox>
<br />
<br />
Second:<asp:TextBox ID="txt2" runat="server"></asp:TextBox>
<br />
<br />
Third<asp:TextBox ID="txt3" runat="server"></asp:TextBox>
<br />
<br />
<asp:Button ID="Button1" runat="server" onclick="Button1_Click"
style="margin-bottom:
0px" Text="Button" />
<br />
<br />
Fourth:<asp:TextBox ID="txt4" runat="server"></asp:TextBox>
</div>
</form>
</body>
</html>
The form looks like below figure1.

Figure1
Now double click on the Button control and add
the following code.
protected void Button1_Click(object
sender, EventArgs e)
{
int a =Convert.ToInt32(txt1.Text)
;
int b= Convert.ToInt32(txt2.Text);
string c = txt3.Text;
txt4.Text =
a.ToString() + b.ToString() + c;
}
Now run the application and test it.

Figure2
Now click on the Button to Concatenate integers
and string.

Figure3