ASP.NET 2.0 - Dynamically create ActiveX object using HtmlGenericControl and call methods / function

[qualitynice]

HELP ... I'm creating an embedded activex object in an asp.net page
using the HtmlGenericControl class. I'm doing this because when I
tried to embed it directly in the aspx page, it stopped working once I
changed it to run on the server (runat="server"). It said the GUID was
wrong. I found code showing how to implement an activex control using
the HtmlGenericControl class from the code behind file, but I can't
figure out how to call functions or methods on it. Any help would be
greatly appreciated.

 

[xhead]

Is the ActiveX object you are calling actually a control? If it is, you
need to use the client-side object scripting model to call it's
functions and methods from within the browser. I don't have much
experience with that, because I try to stay away from client-side
scripting (its yucky to write and debug).

If it is just an ActiveX COM object, then to use it on the server side,
you create a Project Reference to that component in your web project,
and then you can instantiate it in your server-side code like this:

Dim myObject as New CustomActiveXComponent
myObject.DoSomething()

If it is referenced correctly, it should show up in Intellisense when
you declare the object, and when you hit the period, you should see the
methods and properties of the class.

Mike

 

[qualitynice]

Thanks for the reply...

I'm trying to use client-side scripting now, but can't seem to get my
function to recognize the dynamically created object. The script error
I keep getting is "object required". It is however an ActiveX COM
object, but when I create an instance of it, I can't figure out how to
then place it into the webpage. It works fine with windows forms
because when I add a reference to it, it automatically creates the
wrapper and places it into the tool box. In asp, it creates the
wrapper, but won't add it to the tool box for a nice and easy drag and
drop. Thanks again Mike for the reply.

Mike.

 

[Bruce Barker]

if use put a runat=server on an <object> tag, asp.net assumes you are
creating a server side active/x control by guid, not rendering an client
side object tag. it simular to putting a runat=server on <script>. so your
approach is correct.

to access the control from client side (assumming the control is marked safe
for scripting and the browser's security level allows active/x controls),
you need an id tag on the object. because you are using a serverside
control, it generates the id. (view source to see it).

now in browser active/x controls are loaded async, and have a readyState
property that the client script checks to see if its ready. at page load
time, the object should be defined (but may not be ready). so try:

var obj = document.getElementById('name');
if (obj && obj.readyState == 4)
{
// can talk to the object
}


-- bruce (sqlwork.com)

 

[qualitynice]

I finally got the client side script to work. What is strange is how
all of my controls are set to runat="server". I have a button, a text
box, and an activex component all running with the runat="server" tag,
but when I run them remotely, the app behaves as if they are all
running on the local client. It is strange that if I take this code
and just define everything in the aspx page instead of going about from
code behind, I get the guid error. If I take the wrapped activex
control and define it in code behind, I can't seem to figure out how to
add it to the webpage. In a windows form, I just drag and drop the
object onto the form.

{
HtmlInputText rdpText = new HtmlInputText();
rdpText.Attributes.Add("type", "text");
rdpText.Attributes.Add("id", "text1");
//rdpText.Attributes.Add("value", "text");
rdpText.Attributes["runat"] = "server";
Page.Controls.Add(rdpText);

HtmlInputButton rdpButton = new HtmlInputButton();
rdpButton.Attributes.Add("type", "button");
rdpButton.Attributes.Add("id", "button1");
rdpButton.Attributes.Add("name", "button1");
rdpButton.Attributes.Add("value", "Connect");
rdpButton.Attributes["runat"] = "server";
rdpButton.Attributes.Add("onclick", "return
Button1_onclick()");
Page.Controls.Add(rdpButton);

HtmlGenericControl rdp = new HtmlGenericControl("object");
rdp.Attributes["id"] = "rdp";
rdp.Attributes["name"] = "rdp";
rdp.Attributes.Add("classid",
"clsid:7584c670-2274-4efb-b00b-d6aaba6d3850");
rdp.Attributes["runat"] = "server";
rdp.Attributes["width"] = "1034";
rdp.Attributes["height"] = "778";
Page.Controls.Add(rdp);

HtmlGenericControl rdpFunctions = new
HtmlGenericControl("script");
rdpFunctions.Attributes.Add("type", "text/javascript");
rdpFunctions.Attributes.Add("language", "javascript");
rdpFunctions.Attributes["runat"] = "server";

string rdpConnect = "function Button1_onclick()" +
"{" +
"rdp.Width=1034;" +
"rdp.Height=778;" +
"rdp.DesktopWidth=1024;" +
"rdp.DesktopHeight=768;" +
"rdp.Server=text1.value;" +
"rdp.Connect();" +
"}";

string rdpDisconnect = " function disconnect()" +
"{" +
"rdp.Disconnect();" +
"}";

rdpFunctions.InnerHtml = rdpConnect;
rdpFunctions.InnerHtml = rdpFunctions.InnerHtml +
rdpDisconnect;
Page.Controls.Add(rdpFunctions);