I am learning ASP.net, I have a variable in the code behind in c#:
public int hasCar= 1;
and in the aspx file I want to access this variable in javascript function:
function PrintCar( ) {
var ind = <%=this.hasCar%>
alert(ind);
}
but I get error:
does not contain a definition for 'hasCar' and no extension method 'hasCar' accepting a first argument of type 'ASP.vids_aspx' could be found (are you missing a using directive or an assembly reference?)
what is wrong?
thank you
This works for me:
ASPX Page:
<body>
<script type="text/javascript">
function PrintCar( ) {
var ind = <%=this.HasCar%>
alert(ind);
}
</script>
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" OnClientClick="PrintCar();"/>
</form>
</body>
Code Behind
public partial class WebForm1 : System.Web.UI.Page
{
public int HasCar { get; set; }
protected void Page_Load(object sender, EventArgs e)
{
HasCar = 1;
}
}
I want to offer a complimentary answer rather than simply copying what other people have said. Personally I write JS from my C# rather than putting markup in the aspx.
I use this extension method:
public static class ClientScriptManagerExtensions
{
/// <summary>
/// Registers an object as a variable on the page
/// </summary>
public static void RegisterObjectAsVariable(this ClientScriptManager mgr, Type type, string variableName, object objectToEncode)
{
mgr.RegisterClientScriptBlock(type,
string.Concat("ClientScriptManagerExtensions_", variableName),
string.Concat("var ", variableName, " = ", new JavaScriptSerializer().Serialize(objectToEncode), ";"),
true);
}
}
Then to call I do:
this.Page.ClientScript.RegisterObjectAsVariable(typeof(MyPage), "myVariable", new { myProperty = 123});
This creates a js object on your page:
var myVariable =
{
myProperty = 123
};
Which you can access via JS. I find this approach much cleaner and it lets you pass all sorts of complex objects to your code.
Have you the following line at start line of your .aspx page ?
<%@ Page Language="C#" CodeBehind="default.aspx.cs" Inherits="YOURNAMESPACE._default" %>
I have created test project just for your problem.
Try this code
Aspx Code..
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="test.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<script type="text/javascript">
function PrintCar() {
var ind = <%=this.HasCar%>;
alert(ind);
}
</script>
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" OnClientClick="PrintCar()"/>
</form>
</body>
</html>
Code behind...
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace test
{
public partial class WebForm1 : System.Web.UI.Page
{
public int HasCar { get; set; }
protected void Page_Load(object sender, EventArgs e)
{
HasCar = 1;
}
}
}
