How could I change the NavigateUrl property at runtime based on another controls property ?

  • Thread starter Thread starter Radu
  • Start date Start date
R

Radu

Hi, I have a "select" control named "cboSelectScorecardType", defined
as

<select id="cboSelectScorecardType"
size="1"
runat="server">
</select>

which shows a list of files on my drive. It does not post back, nor do
I want it to. After the user selects a document in the combo, I want a
hyperlink defined in the same page as

<asp:HyperLink
Target="_blank"
NavigateUrl="javascript:Concat();"
ID="cmdOpenScorecardPreview"
Text="here"
runat="server">
</asp:HyperLink>

to have the NavigateURL property set to whatever the combo points to,
so that the user can click on it to preview the document selected in
the combo, so therefore I tried to use this:

function MyConcat()
{
return String.Concat(
"~",
"\Scorecard Previews\",

cboSelectScorecardType.Items(cboSelectScorecardType.SelectedIndex).ToString,

".doc"
);
}

I confess I don't really know JavaScript.

What am I doing wrong ? Is there a simpler way to do this ? There is no
server event I can write my code into...

Thanks, Alex
 
Hi, Milosz, it works great, thank you very much !

:-)) raduspage.aspx... Cute :-))

I read the code, I translated it (mentally) from C# to VB (I don't know
much C#), and it makes sense.

However, I have one question: It says "OnChange is not a valid
attribute of element DropDownList" - however, hmmmmm, it works.

Thanks again - I'll work now on translating it into VB and
incorporating it into my program.

Alex (or.... Radu) :-))


Hi radu,

I see you don't quite understand the asp.net concept as you're mixing server
and client sides. But don't worry, i created a simple example to help you
with dynamic document previewing. Example consists of two pages, one
containing combo box for selecting word document, and second, which displays
the document. Please note you have to populate combo box with file names
users can preview (i.e. using system.IO.File.GetFiles() method)

-- begin raduspage.aspx html code --

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="RadusPage.aspx.cs"
Inherits="RadusPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList runat="server" ID="fileList" onchange="previewFile(this)">
<asp:ListItem Text="Please select a file"/>
<asp:ListItem Text="file1.doc"/>
<asp:ListItem Text="file2.doc"/>
<asp:ListItem Text="file3.doc"/>
</asp:DropDownList>
</div>

<div style="padding: 10px; border: solid 1px black; width: 500px;
height: 350px">
<iframe src="preview.aspx" runat="server" id="viewer"
frameborder="0"></iframe>
</div>

<script language="javascript">
//<!--
function previewFile(cbo)
{
var index = cbo.selectedIndex;
// first item is ' please select...'
if (index > 0)
{
var ifr = document.getElementById('<%=viewer.ClientID %>');
ifr.src = 'preview.aspx?file=' + escape(cbo.options[index].text);
}
}
//-->
</script>

</form>
</body>
</html>
-- end --

Second apsx page: Remove all html code from this page - leave

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="preview.aspx.cs"
Inherits="preview" %>

only

-- begin preview.aspx c# code behind --

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 preview : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string value = Request.QueryString["file"];

if (String.IsNullOrEmpty(value))
{
Response.Write("File has not been selected yet.");
}
else
{
AttachFile(value);
}
}

private void AttachFile(string file)
{
// i put my example word files in application's root directory
file = Server.MapPath("~/" + file);

if (System.IO.File.Exists(file))
{
// determine the MIME content type i.e. using extension
// for word documents MIME type equals : application/msword
Response.ContentType = "application/msword";
Response.WriteFile(file);
}
else
{
Response.Write("File cannot be found");
}

Response.End();
}

}-- end c# code

Hope this helps
Milosz



Radu said:
Hi, I have a "select" control named "cboSelectScorecardType", defined
as
Click to expand...
<select id="cboSelectScorecardType"
size="1"
runat="server">
</select>
Click to expand...
which shows a list of files on my drive. It does not post back, nor do
I want it to. After the user selects a document in the combo, I want a
hyperlink defined in the same page as

to have the NavigateURL property set to whatever the combo points to,
so that the user can click on it to preview the document selected in
the combo, so therefore I tried to use this:
Click to expand...
function MyConcat()
{
return String.Concat(
"~",
"\Scorecard Previews\",


I confess I don't really know JavaScript.
Click to expand...
What am I doing wrong ? Is there a simpler way to do this ? There is no
server event I can write my code into...
Click to expand...
Thanks, Alex- Hide quoted text -- Show quoted text -
Click to expand...
Click to expand...
 
Hi again Radu,

Parser error "OnChange is not a valid attribute of element DropDownList" is
caused by the fact DropDownControl doesn’t have such property, but it will be
rendered as expected in representing HTML code (as you may know dropdownlist
renders as <select> html tag). Such trick is allowed and it’s called
“expandoâ€. You can of course avoid it, removing OnChange=â€â€ attribute from
DropDownList and add it programmatically onpageload event handler:

cboSelectScorecardType.Attributes["onchange"] = "previewFile(this)"

Regards

Milosz



Radu said:
Hi, Milosz, it works great, thank you very much !

:-)) raduspage.aspx... Cute :-))

I read the code, I translated it (mentally) from C# to VB (I don't know
much C#), and it makes sense.

However, I have one question: It says "OnChange is not a valid
attribute of element DropDownList" - however, hmmmmm, it works.

Thanks again - I'll work now on translating it into VB and
incorporating it into my program.

Alex (or.... Radu) :-))


Hi radu,

I see you don't quite understand the asp.net concept as you're mixing server
and client sides. But don't worry, i created a simple example to help you
with dynamic document previewing. Example consists of two pages, one
containing combo box for selecting word document, and second, which displays
the document. Please note you have to populate combo box with file names
users can preview (i.e. using system.IO.File.GetFiles() method)

-- begin raduspage.aspx html code --

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="RadusPage.aspx.cs"
Inherits="RadusPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList runat="server" ID="fileList" onchange="previewFile(this)">
<asp:ListItem Text="Please select a file"/>
<asp:ListItem Text="file1.doc"/>
<asp:ListItem Text="file2.doc"/>
<asp:ListItem Text="file3.doc"/>
</asp:DropDownList>
</div>

<div style="padding: 10px; border: solid 1px black; width: 500px;
height: 350px">
<iframe src="preview.aspx" runat="server" id="viewer"
frameborder="0"></iframe>
</div>

<script language="javascript">
//<!--
function previewFile(cbo)
{
var index = cbo.selectedIndex;
// first item is ' please select...'
if (index > 0)
{
var ifr = document.getElementById('<%=viewer.ClientID %>');
ifr.src = 'preview.aspx?file=' + escape(cbo.options[index].text);
}
}
//-->
</script>

</form>
</body>
</html>
-- end --

Second apsx page: Remove all html code from this page - leave

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="preview.aspx.cs"
Inherits="preview" %>

only

-- begin preview.aspx c# code behind --

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 preview : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string value = Request.QueryString["file"];

if (String.IsNullOrEmpty(value))
{
Response.Write("File has not been selected yet.");
}
else
{
AttachFile(value);
}
}

private void AttachFile(string file)
{
// i put my example word files in application's root directory
file = Server.MapPath("~/" + file);

if (System.IO.File.Exists(file))
{
// determine the MIME content type i.e. using extension
// for word documents MIME type equals : application/msword
Response.ContentType = "application/msword";
Response.WriteFile(file);
}
else
{
Response.Write("File cannot be found");
}

Response.End();
}

}-- end c# code

Hope this helps
Milosz



Radu said:
Hi, I have a "select" control named "cboSelectScorecardType", defined
as
Click to expand...
<select id="cboSelectScorecardType"
size="1"
runat="server">
</select>
Click to expand...
which shows a list of files on my drive. It does not post back, nor do
I want it to. After the user selects a document in the combo, I want a
hyperlink defined in the same page as

to have the NavigateURL property set to whatever the combo points to,
so that the user can click on it to preview the document selected in
the combo, so therefore I tried to use this:
Click to expand...
function MyConcat()
{
return String.Concat(
"~",
"\Scorecard Previews\",


I confess I don't really know JavaScript.
Click to expand...
What am I doing wrong ? Is there a simpler way to do this ? There is no
server event I can write my code into...
Click to expand...
Thanks, Alex- Hide quoted text -- Show quoted text -
Click to expand...
Click to expand...
Click to expand...
 
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