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Saturday, September 13, 2008

Using System.Windows.Forms.WebBrowser.ActiveXInstance

Expanding the WebBrowser control functionalities by using its ActiveXInstance property.


The WebBrowser control has a property called ActiveXInstance which is its run-time ActiveX instance and exposes many other methods/properties not available in the main control.

However, since ActiveXInstance is Object and requires late-binding to access all its methods and properties, Option Strict needs to be turned off in order to use it.

To use the WebBrowser extra functionalities: call WebBrowser.ActiveXInstance.ExecBB()

Define enums for use with ExecBB:

 Private Enum Exec
 OLECMDID_OPTICAL_ZOOM = 63
 OLECMDID_SELECTALL = 17
 OLECMDID_COPY = 12
 OLECMDID_CLEARSELECTION = 18
 End Enum

 Private Enum ExecOpt
 OLECMDEXECOPT_DODEFAULT = 0
 OLECMDEXECOPT_PROMPTUSER = 1
 OLECMDEXECOPT_DONTPROMPTUSER = 2
 OLECMDEXECOPT_SHOWHELP = 3
 End Enum

Copy selected text to clipboard:

Me.WebSMSView.ActiveXInstance.ExecWB(Exec.OLECMDID_COPY, ExecOpt.OLECMDEXECOPT_DODEFAULT)

Select all text:

Me.WebSMSView.ActiveXInstance.ExecWB(Exec.OLECMDID_SELECTALL, ExecOpt.OLECMDEXECOPT_DODEFAULT)

Zoom to 75%:

Me.WebSMSView.ActiveXInstance.ExecWB(Exec.OLECMDID_OPTICAL_ZOOM, ExecOpt.OLECMDEXECOPT_DODEFAULT, 75, 0)

To use a custom context menu in the WebBrowser control, the default context menu needs to be disabled by setting WebBrowser.IsWebBrowserContextMenuEnabled to false.


Reference:

  • Copy the contents of the WebBrowser control to the Clipboard
  • Using ExecWB with the native .NET 2.0 WebBrowser control
  • Allow only Copy/Paste Context Menu in System.Windows.Forms.WebBrowser Control
  • ExecWB Method
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    4 comments:

    1. AnonymousMay 6, 2015 at 9:13 PM

      Hi, I know this is a long shot b/c this article is so old, but I'm having issues getting the SelectAll to work with my ActiveXInstance. I keep getting the error "Trying to revoke a drop target that has not been registered." Does anyone know a way to fix that error? Thanks!
      Tim

      ReplyDelete
    2. MDMay 7, 2015 at 1:30 AM

      Hi,

      This error happens usually because you try to access the WebBrowser control ActiveX instance before it is ready. Depending on your use case, you can try to wait for a while before calling SelectAll, or use QueryStatusWB to check when it's ready, see this for more info - http://www.vbforums.com/showthread.php?625308-WebBrowser-Error-Trying-to-revoke-a-drop-target-that-has-not-been-registered

      Another issue could be incompatible argument type for the 3rd and 4th parameter. Depending on your language (VB or C#), you can try to pass either IntPtr.Zero or null and see if it makes a different. Refer to this https://social.msdn.microsoft.com/Forums/en-US/83fd2599-1afa-4435-8fff-95708ac18c1e/trying-to-revoke-a-drop-target-that-has-not-been-registered-exception-from-hresult-0x80040100?forum=vblanguage for more info

      Let me know if this helps

      ReplyDelete
    3. AnonymousJuly 23, 2015 at 11:44 PM

      Wow, I apologize. I completely forgot to check back here for your answer. I was not able to get the SelectAll to work, even with the ideas you suggested. I was using VB.net. However, I was able to get the SaveAs command to work and just used a PDF parsing method to grab all the text. Thanks for your response though. I really appreciate it!
      Tim

      ReplyDelete
      Replies
      1. MDJuly 23, 2015 at 11:46 PM

        No problem, glad you got it to work and thanks for sharing your workaround too :)

        Delete

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