ASP.NET Tutorial/HTML Controls/Text input
Read input from text field, do calculation then output to the save page (C#)
<source lang="csharp">
File: Default.aspx
<%@ Page Language="C#" AutoEventWireup="true"
CodeFile="Default.aspx.cs" Inherits="CurrencyConverter" %>
<!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> <title>Currency Converter</title> </head> <body> <form ID="Form1" method="post" runat="server">
Convert: <input type="text" ID="US" runat="server"/>U.S. dollars to <select ID="Currency" runat="server" />
<input type="submit" value="OK" ID="Convert" runat="server" OnServerClick="Convert_ServerClick" /> <input type="submit" value="Show Graph" ID="ShowGraph" runat="server" OnServerClick="ShowGraph_ServerClick" />
<img ID="Graph" alt="Currency Graph" scr="" runat="server" />
</form> </body>
</html>
File: Default.aspx.cs using System; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; public partial class CurrencyConverter : System.Web.UI.Page {
protected void Page_Load(Object sender, EventArgs e) { if (this.IsPostBack == false) { Currency.Items.Add(new ListItem("Euros", "0.5")); Currency.Items.Add(new ListItem("Japanese Yen", "100")); Currency.Items.Add(new ListItem("Canadian Dollars", "2")); } Graph.Visible = false; } protected void Convert_ServerClick(object sender, EventArgs e) { decimal amount; bool success = Decimal.TryParse(US.Value, out amount); if (success) { ListItem item = Currency.Items[Currency.SelectedIndex]; decimal newAmount = amount * Decimal.Parse(item.Value); Result.InnerText = amount.ToString() + " U.S. dollars = "; Result.InnerText += newAmount.ToString() + " " + item.Text; } else { Result.InnerText = "The number you typed in was not in the correct format. "; Result.InnerText += "Use only numbers."; } } protected void ShowGraph_ServerClick(object sender, EventArgs e) { Graph.Src = "Pic" + Currency.SelectedIndex.ToString() + ".png"; Graph.Visible = true; }
}</source>
Set value to html:textbox in page load event (VB.net)
<source lang="csharp">
<%@ Page Language="VB" %> <script runat="server">
sub Page_Load(Sender as object, e as EventArgs) tbMyText.Value = "This is the page load event!" end sub
</script> <html><body>
<form runat="server"> <input type="text" size="25" id="tbMyText" runat="server" /> </form>
</body></html></source>
TextBox server changed event
<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="ChangeEvents" %> <!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>Change Events</title>
</head> <body>
<form id="form1" runat="server" >
<select runat="server" id="List1" size="5" multiple Name="List1" onserverchange="List1_ServerChange"> <option>Option 1</option> <option>Option 2</option> </select>
<input type="text" runat="server" ID="Textbox1" Size="10" Name="Textbox1" OnServerChange="Ctrl_ServerChange">
<input type="checkbox" runat="server" ID="Checkbox1" Name="Checkbox1" OnServerChange="Ctrl_ServerChange">Option text
<input type="submit" runat="server" ID="Submit1" Name="cmdSubmit" value="Submit Query" onserverclick="Submit1_ServerClick">
</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 ChangeEvents : System.Web.UI.Page {
protected void Page_Load(object sender, System.EventArgs e) { if (!Page.IsPostBack) { List1.Items.Add("Option 3"); List1.Items.Add("Option 4"); List1.Items.Add("Option 5"); } } protected void Ctrl_ServerChange(object sender, System.EventArgs e) {Response.Write("
} protected void List1_ServerChange(object sender, EventArgs e) {Response.Write("
");
foreach (ListItem li in List1.Items) { if (li.Selected) Response.Write(" - " + li.Value + "Response.Write("
"); } } protected void Submit1_ServerClick(object sender, EventArgs e) {
}
}</source>