WebBrowser control and InvokeScript

This is a little code nugget I planned to blog about a while ago, but forgot, so my recap and reasoning is not a 100% but hopefully it might be of help to someone struggelig with making the System.Windows.Forms.WebBrowser control execute scripts programatically.

I started out using the WebBrowser.InvokeScript method to force execution of clientside scripts in the page that was loaded in my WebBrowser control:

HtmlWindow win = doc.Window;
doc.InvokeScript("Update_UI_From_Values();");

This is where my reasoning is not complete (because i didn't bother to actually reproduce the original problem..), but basically it didn't work as expected. After some Reflector action I figured out that the mshtml.IHTMLWindow2.execScript method wasn't actually directly mapped into the new WebBrowser APIs and I figured I'd give it a go and add a reference to Microsoft.mshtml.dll (COM component Microsoft HTML Object Library):

mshtml.IHTMLWindow2 win = (mshtml.IHTMLWindow2)propertyEditorWebBrowser.Document.Window.DomWindow;
win.execScript("Update_UI_From_Values();", "javascript");

This had the desired effect and the script executed. Too bad the managed option didn't do the job.

4 Comments

  • At least in C# 2005 Express, the following works:

    doc.InvokeScript("Update_UI_From_Values");

    The parameter is just a function name... perhaps the "();" after it was what was breaking it for you.

  • I have been running into problems using InvokeScript to return the array from a JavaScript function. Works fine for a single string though.

    Any help?

  • Is there a way to pass the parameters while calling execScript Method such as win.execScript("Update_UI_From_Values(number1, number2,number3);", "javascript"); as I have to pass three values from C# variables to Javascript function. I do appreciate your help!!!

  • Hi,

    object result = doc.InvokeScript("myfunction", new object[] { "arg1", 2, "etc" });

    calls 'myfunction' in the page passing the parameters "arg1", 2, "etc"
    the 'result' object will have the same value as the result of the active scripting call.

    F.

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