w3digital
asked on
C# code request: Using "if" "else" in a user control to write javascript into the body "onload" event
I have an admin system that uses "user controls" to provide the open head and body (header.ascx) and close body (footer.ascx) of the admin centre html pages.
So for each page I (currently) have something like:
<%@ Page language="c#" Codebehind="default.aspx.c
<form id="mainForm" method="post" runat="server">
Main Content Here
</form>
Each page references a class containing the code section below to load the header and footer controls at the start and end of the page respectively:
protected override void OnInit(System.EventArgs e)
{
this.Controls.AddAt(0, LoadControl("Header.ascx")
base.OnInit(e);
this.Controls.Add(LoadCont
}
The header control currently looks like this:
<%@ Control Language="c#" AutoEventWireup="false" Codebehind="Header.ascx.cs
<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>
<html>
<head>
<title>Admin Center</title>
<meta name='robots' content='noindex,nofollow'
<body>
Here's the question:
I'm reworking an old ASP3 script that simply does this:
<%
show_what = "this_menu_option" 'Hard coded into the top of each main page (but could be passed in the QueryString
If show_what <> "" Then
Response.Write("<body onload=""MM_showHideLayers
Else
Response.Write("<body>")
End If
%>
So currently the Header.ascx control includes the <body> tag, so how would I get the Header.ascx to pickup on the "show_what" variable and replicate the code output as shown above in the ASP 3 example (this time in C#)?
Many thanks.
So for each page I (currently) have something like:
<%@ Page language="c#" Codebehind="default.aspx.c
<form id="mainForm" method="post" runat="server">
Main Content Here
</form>
Each page references a class containing the code section below to load the header and footer controls at the start and end of the page respectively:
protected override void OnInit(System.EventArgs e)
{
this.Controls.AddAt(0, LoadControl("Header.ascx")
base.OnInit(e);
this.Controls.Add(LoadCont
}
The header control currently looks like this:
<%@ Control Language="c#" AutoEventWireup="false" Codebehind="Header.ascx.cs
<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>
<html>
<head>
<title>Admin Center</title>
<meta name='robots' content='noindex,nofollow'
<body>
Here's the question:
I'm reworking an old ASP3 script that simply does this:
<%
show_what = "this_menu_option" 'Hard coded into the top of each main page (but could be passed in the QueryString
If show_what <> "" Then
Response.Write("<body onload=""MM_showHideLayers
Else
Response.Write("<body>")
End If
%>
So currently the Header.ascx control includes the <body> tag, so how would I get the Header.ascx to pickup on the "show_what" variable and replicate the code output as shown above in the ASP 3 example (this time in C#)?
Many thanks.
or you can do it in code by gaining a reference to the body tag and simply adding an attribute.
ASKER
Thanks Len,
Acutally no, I don't think that is what I am after as I will need to specific on a page by page basis which javascript menu option I wish to call from the body onload event handler. So the "show_what" variable will be specified in ... say ... the default.aspx.cs.
Then the header.aspx should output the code:
<body onload="MM_showHideLayers(
I did try something like the code you have submitted above and got the following error:
The name 'show_what' does not exist in the class or namespace 'ASP.Header_ascx'
I was thinking something like this (but that works...)
// CODE behind default.aspx.cs
private void Page_Load(object sender, System.EventArgs e)
{
show_what = "admin_menu"; // put here for example only
if (show_what != "")
{
// below code is rubbish but the sort of thing I need to programmatically add
// an onload attribute to <body> tag on a page by page basis
Body.Attributes["onload"] = "MM_showHideLayers('" + show_what + "','','show')";
}
}
Acutally no, I don't think that is what I am after as I will need to specific on a page by page basis which javascript menu option I wish to call from the body onload event handler. So the "show_what" variable will be specified in ... say ... the default.aspx.cs.
Then the header.aspx should output the code:
<body onload="MM_showHideLayers(
I did try something like the code you have submitted above and got the following error:
The name 'show_what' does not exist in the class or namespace 'ASP.Header_ascx'
I was thinking something like this (but that works...)
// CODE behind default.aspx.cs
private void Page_Load(object sender, System.EventArgs e)
{
show_what = "admin_menu"; // put here for example only
if (show_what != "")
{
// below code is rubbish but the sort of thing I need to programmatically add
// an onload attribute to <body> tag on a page by page basis
Body.Attributes["onload"] = "MM_showHideLayers('" + show_what + "','','show')";
}
}
ASKER
Ah, I just saw gregoryyoung's comment after submitting my thoughts.
That's what I'm after.
gregoryyoung, can you provide a code sample please?
That's what I'm after.
gregoryyoung, can you provide a code sample please?
ASKER CERTIFIED SOLUTION
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ASKER
Thanks gregoryyoung,
I reckon I'm almost there but am doing something wrong.
Here's the Page_Load code:
private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
this.PageTitle = "Admin main menu";
HtmlGenericControl bodytag = (HtmlGenericControl)FindCo
bodytag.Attributes["onload
}
Here's the error message: Any ideas?
Exception Details: System.NullReferenceExcept
Source Error:
Line 18: HtmlGenericControl bodytag = (HtmlGenericControl)FindCo
Line 19: bodytag.Attributes["onload
Line 20: }
Line 21:
Thanks.
I reckon I'm almost there but am doing something wrong.
Here's the Page_Load code:
private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
this.PageTitle = "Admin main menu";
HtmlGenericControl bodytag = (HtmlGenericControl)FindCo
bodytag.Attributes["onload
}
Here's the error message: Any ideas?
Exception Details: System.NullReferenceExcept
Source Error:
Line 18: HtmlGenericControl bodytag = (HtmlGenericControl)FindCo
Line 19: bodytag.Attributes["onload
Line 20: }
Line 21:
Thanks.
is bodytag null ?
can you also post your aspx ...
can you also post your aspx ...
remember you need to put runat=server id= on the body tag.
Greg
Greg
ASKER
Hi Grey
Yeah, I did ensure the runat=server etc but I was missing it - doh!
I have this:
<body id="body" runat="server">
then in the default.aspx.cs I have:
private void Page_Load(object sender, System.EventArgs e)
{
HtmlGenericControl bodytag = (HtmlGenericControl)FindCo
bodytag.Attributes["onload
}
But I guess having the open body in the header.ascx file and the close body in the footer.ascx file is causing problems as I get the below error:
Parser Error Message: Unexpected end of file looking for </body> tag.
I imagine calling the code in the Page_Load event is the wrong place. Is there anywhere else I should put this code that will work? Or am I asking the impossible when <body> is in one user control and </body> is in another?
Thanks very much for your help you certainly deserve the points.
Yeah, I did ensure the runat=server etc but I was missing it - doh!
I have this:
<body id="body" runat="server">
then in the default.aspx.cs I have:
private void Page_Load(object sender, System.EventArgs e)
{
HtmlGenericControl bodytag = (HtmlGenericControl)FindCo
bodytag.Attributes["onload
}
But I guess having the open body in the header.ascx file and the close body in the footer.ascx file is causing problems as I get the below error:
Parser Error Message: Unexpected end of file looking for </body> tag.
I imagine calling the code in the Page_Load event is the wrong place. Is there anywhere else I should put this code that will work? Or am I asking the impossible when <body> is in one user control and </body> is in another?
Thanks very much for your help you certainly deserve the points.
ASKER
Ah, I see it's not the code, it's the actual Header.ascx user control that's playing up. I think I'm going to bring the body tag into the main file. That'll be simpler.
Yes, that sorts it!
Ta very much
Yes, that sorts it!
Ta very much
no worries. glad to help ...
btw its a nice thing to put in a page base class for reuse :)
btw its a nice thing to put in a page base class for reuse :)
Is this what you are after?
<%
string show_what = "this_menu_option"; //Hard coded into the top of each main page (but could be passed in the QueryString
if (show_what != ""){
Response.Write("<body onload=""MM_showHideLayers
} else {
Response.Write("<body>");
}
%>
cheers
Len