A very easy .NET “Applet”

Download demo project - 9.08 Kb

Sample Image - CSharpApplet.gif

Introduction

Some time ago, I needed my web application to interact with a specific hardware in the computer, but I didn't want to write an ActiveX, I wanted to write it in a .NET language. So I made a search in the web and I found some examples that helped me on that. In this article I will use a UserControl as an applet on my .htm page.

This example of "applet" doesn't make anything relevant. It's only to show how to put a Windows Form's code in a web page and interact with its properties and methods.

How it works?

Everything is very simple, it isn’t a “black box”. I created a Class Library project, then I added a Windows Forms UserControl and drag-and-drop'ed some components. Then I added an HTML page in the same project and I changed the code to:

<html>
   <head>
   <title>My Applet</title>
   <script language="javascript">
   <!--

     function Button1_onclick() {
        document.getElementById("myID").MyMethodReset();
    }

   //-->
  </script>
  </head>
  <body>
      <OBJECT id="myID" height="150" width="300" 
        classid="http:bin/release/CSharpApplet.dll#CSharpApplet.MyApplet"
        VIEWASTEXT>
     </OBJECT>
    <P>
    <INPUT id="Button1" type="button" value="Reset by way of javascript" 
        name="Reset" onclick="return Button1_onclick()">
  </body>
</html>

On the tag OBJECT the property classid is composed by the path (I used relative path) and name of the DLL, plus namespace and class name.

Note that MyApplet (UserControl) has a button with the caption “Reset” that calls the MyMethodReset public method, setting the value of the progress bar to zero. And on the HTML file, I have another button that calls the same public method MyMethodReset by way of JavaScript!

Remarks

You must create a WebSharing at the folder CSharpApplet from this source code example. Then run by, for example: http://localhost/CSharpApplet/MyApplet.htm.

Of course, .NET Framework is to be installed on clients.

Depending of what your user control will do and where it will run (by intranet/Internet), it will be necessary to trust the assembly by making proper settings on Administrative Tools > Microsoft .NET Framework Configuration/Wizards.

That’s all and sorry for my bad English!

Revision history

20 February 2005
English improvements :P

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Welliton Alves Toledo

Web Developer

Brazil

Member

Welliton is a nice brazilian guy.
He started the kidding with software with his "top" PC-AT 286 in 1991 when he was 14 years old.
Now he begins solo career in a software company (http://www.actuar.com.br) in Goiânia-Goiás - Brazil

Article Top

Poor

Excellent

Add a reason or comment to your vote: x
Votes of 3 or less require a comment

Comments and Discussions

You must Sign In to use this message board. (secure sign-in)

Search this forum
	Profile popups Noise Layout Per page

Not working for computers outside localhost

Ivn Y.

2:07 30 Jun '11

Drag and Drop the controls at runtime in ASP.NET application

Akshay srikanth

5:33 4 Aug '09

How to access into java Web application

bhangale.parag

4:29 12 Jan '09

Has anyone got this to work with non-.NET (ActiveX) controls?

Sanx72

4:47 21 Aug '08

I'd like to embed a non-.NET control within the applet but this appears to fail.

I am embedding a VS 6.0 ActiveX control in the applet, which works fine outside of the browser, but doesn't work at all inside IE. I've tried a few different VS 6.0 ActiveX's (including Microsoft ones) and even built my ActiveX project using VS 2008 but I just get a red X in the browser where the control should be.

I'm guessing I need to tell .NET what the ActiveX object is. VS 2008 creates the interop references in the project but I wonder if these need to be registered somehow in .NET.

Anyone got any advice?