ASP.NET Tutorial/ASP.net Controls/Command
Check CommandArgument (VB.net)
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Collections.Generic" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Private groceries As New List(Of String)()
Sub Page_Load()
groceries.Add("A")
groceries.Add("B")
groceries.Add("C")
End Sub
Sub Sort_Command(ByVal sender As Object, ByVal e As CommandEventArgs)
If e.rumandName = "Sort" Then
Select Case e.rumandArgument.ToString()
Case "ASC"
groceries.Sort(AddressOf SortASC)
Case "DESC"
groceries.Sort(AddressOf SortDESC)
End Select
End If
End Sub
Sub Page_PreRender()
bltGroceries.DataSource = groceries
bltGroceries.DataBind()
End Sub
Function SortASC(ByVal x As String, ByVal y As String) As Integer
Return String.rupare(x, y)
End Function
Function SortDESC(ByVal x As String, ByVal y As String) As Integer
Return String.rupare(x, y) * -1
End Function
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Button Command</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button
id="btnSortAsc"
Text="Sort ASC"
CommandName="Sort"
CommandArgument="ASC"
OnCommand="Sort_Command"
Runat="server" />
<asp:Button
id="btnSortDESC"
Text="Sort DESC"
CommandName="Sort"
CommandArgument="DESC"
OnCommand="Sort_Command"
Runat="server" />
<br /><br />
<asp:BulletedList
id="bltGroceries"
Runat="server" />
</div>
</form>
</body>
</html>
Command name
<%@ 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.rumandName)
{
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";
}
}
}
Handling the Command Event
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Collections.Generic" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
private List<String> groceries = new List<String>();
void Page_Load()
{
groceries.Add("Milk");
groceries.Add("Steak");
groceries.Add("Fish");
}
protected void Sort_Command(object sender, CommandEventArgs e)
{
if (e.rumandName == "Sort")
{
switch (e.rumandArgument.ToString())
{
case "ASC":
groceries.Sort(SortASC);
break;
case "DESC":
groceries.Sort(SortDESC);
break;
}
}
}
void Page_PreRender()
{
bltGroceries.DataSource = groceries;
bltGroceries.DataBind();
}
int SortASC(string x, string y)
{
return String.rupare(x, y);
}
int SortDESC(string x, string y)
{
return String.rupare(x, y) * -1;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Button Command</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button
id="btnSortAsc"
Text="Sort ASC"
CommandName="Sort"
CommandArgument="ASC"
OnCommand="Sort_Command"
Runat="server" />
<asp:Button
id="btnSortDESC"
Text="Sort DESC"
CommandName="Sort"
CommandArgument="DESC"
OnCommand="Sort_Command"
Runat="server" />
<br /><br />
<asp:BulletedList
id="bltGroceries"
Runat="server" />
</div>
</form>
</body>
</html>