CODEWITHSUNDEEP
javascriptc#winforms
Kieran Quinn
Kieran Quinn

Reputation: 1115

Call winform function from IE browser

I have a winform that screen scrapes another application and generates a html file. I'd like to add js to the html file so that when a user clicks a heading, it will send a string and trigger a function within the winform.

I've been researching this for a while now but all of the possible solutions I've seen involve the webbrowser control, which I'm not using and don't intend to use.

Is it possible to call a winform function from an IE page via js?

UPDATE: Now considering a webbrowser control.

Upvotes: 2

Views: 620

Answers (2)

Andrei Bucurei
Andrei Bucurei

Reputation: 2438

If you use WebBrowser control you can set the object for scripting property to a class with public methods that you want to expose to javascript:

[ComVisibleAttribute(true)] //required
class MyJsInterface
{
  public string Test()
  {
    return "Hello World!";
  }
}

browser1.ObjectForScripting = new MyJsInterface(); //for example

Then, you can call the methods in MyJsInterface from javascript using window.external object:

//add this script to document.onload or in a script tag at the end of the document

//var headings = document.getElementsByClassName("heading");
//var headings = document.getElementsByTagName("h1");
for (var i = 0; i < headings.length; i++)
{
   var element = headings[i];
 //element.addEventListener("click", function () {
   element.attachEvent("click", function () {
     var text = window.external.Test();
     alert(text);
   }
}

In Internet Explorer versions prior to IE 9, you have to use attachEvent rather than the standard addEventListener: Legacy Internet Explorer and attachEvent

It's also possible to invoke javascript methods from code behind. Read more here:
Implement Two-Way Communication Between DHTML Code and Client Application Code

Upvotes: 3

Raheel Khan
Raheel Khan

Reputation: 14787

Override WndProc (refer here and here) on your form and listen for WM_LBUTTONDOWN messages. Translate the points based on the location of the Web Browser control. Then use IHtmlDocument (mshtml object library) to access the DOM and find the element at that position (using elementFromPoint).

Upvotes: 1

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