<%@ Page Language="C#" AutoEventWireup="true" CodeFile=Default.aspx.cs" Inherits="CommandTest" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Command Button Test</title>
</head>
<body>
<form id="form1" runat="server">
<div id="container">
<h1>Simple Calculator</h1>
<div class="box">
<asp:TextBox ID="txtValue1" runat="server" />
<asp:Button Text="+" runat="server" ID="btnAdd" Width="30px"
OnCommand="Button_Command" CommandName="add" />
<asp:Button Text="-" runat="server" ID="btnSubtract" Width="30px"
OnCommand="Button_Command" CommandName="subtract" />
<br/>
<asp:TextBox ID="txtValue2" runat="server" />
<asp:Button Text="*" runat="server" ID="btnMultiply" Width="30px"
OnCommand="Button_Command" CommandName="multiply" />
<asp:Button Text="/" runat="server" ID="btnDivide" Width="30px"
OnCommand="Button_Command" CommandName="divide" />
</div>
<asp:Label ID="labMessage" runat="server" />
</div>
</form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class CommandTest : System.Web.UI.Page
{
protected void Button_Command(Object o, CommandEventArgs e)
{
double dVal1 = 0.0;
double dVal2 = 0.0;
bool val1okay = Double.TryParse(txtValue1.Text, out dVal1);
bool val2okay = Double.TryParse(txtValue2.Text, out dVal2);
if (val1okay && val2okay)
{
double result = 0;
string op = "";
switch (e.CommandName)
{
case "add":
op = "+";
result = dVal1 + dVal2;
break;
case "subtract":
op = "-";
result = dVal1 - dVal2;
break;
case "multiply":
op = "*";
result = dVal1 * dVal2;
break;
case "divide":
op = "/";
result = dVal1 / dVal2;
break;
}
labMessage.Text = txtValue1.Text + op + txtValue2.Text + "=" + result;
}
else
{
labMessage.Text = "Unable to compute a value with these values";
}
}
}