Prevent pasting object in Word Document

Question

Hi

I create an add-in Word 2007 to check user copy and paste something in the document. When user want to paste something, I need to check the data user will paste and prevent the pasting process.

Which event of which object or interface I should register to implement the interception?

Thanks and regards

---

tui

Answer 1

Hi tui,

Word 2007 Object Mode doesn't provide any clipboard event, thus we need to use some Windows API to achieve your objective,following code is a illustration about how we retrieve the content while user perfrom the copy command.

The idea is when user perform a copy command, it will cause a "drawcllipboard" message be sent.
so we find the Word main window then monitor it's messages by using WndProc method

public partial class ThisAddIn

{

#region NativeMethods

[System.Runtime.InteropServices.DllImport("User32.dll")]

public static extern IntPtr SetClipboardViewer(IntPtr hWnd);

[System.Runtime.InteropServices.DllImportAttribute("user32.dll", EntryPoint = "FindWindowExW")]

public static extern System.IntPtr FindWindowExW([System.Runtime.InteropServices.InAttribute()] System.IntPtr hWndParent, [System.Runtime.InteropServices.InAttribute()] System.IntPtr hWndChildAfter, [System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPWStr)] string lpszClass, [System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPWStr)] string lpszWindow);

[System.Runtime.InteropServices.DllImport("user32.dll")]

public static extern int FindWindow(String className, String windowName);

#endregion

private void ThisAddIn_Startup(object sender, System.EventArgs e)

{

Native_GetWindowMessage();

}

void Native_GetWindowMessage()

{

string className = "OpusApp";

string windowName = Application.ActiveDocument.Name + " - Microsoft Word";

IntPtr h = Process.GetCurrentProcess().MainWindowHandle;

h = (IntPtr)FindWindow(className, windowName);

SubclassHWND s = new SubclassHWND();

s.AssignHandle(h);

s._ClipboardViewerNext = SetClipboardViewer(s.Handle);

}

private void ThisAddIn_Shutdown(object sender, System.EventArgs e)

{

}

#region VSTO generated code

/// <summary>

/// Required method for Designer support - do not modify

/// the contents of this method with the code editor.

/// </summary>

private void InternalStartup()

{

this.Startup += new System.EventHandler(ThisAddIn_Startup);

this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);

}

#endregion

}

public class SubclassHWND : System.Windows.Forms.NativeWindow

{

[System.Runtime.InteropServices.DllImport("user32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]

public static extern int SendMessage(IntPtr hwnd, int wMsg, IntPtr wParam, IntPtr lParam);

public IntPtr _ClipboardViewerNext;

protected override void WndProc(ref Message m)

{

if ((Msgs)m.Msg == Msgs.WM_DRAWCLIPBOARD)

{

Debug.Print(System.Windows.Forms.Clipboard.GetText(System.Windows.Forms.TextDataFormat.Text));

SendMessage(_ClipboardViewerNext, m.Msg, m.WParam, m.LParam);

}

else

{

base.WndProc(ref m);

}

}

public enum Msgs

{

WM_DRAWCLIPBOARD = 0x0308

}

}

Here's a link of the source where my idea comes:
http://www.radsoftware.com.au/articles/clipboardmonitor.aspx

Thanks

---

We have published a VSTO FAQ recently, you can view them from the entry thread http://social.msdn.microsoft.com/Forums/en/vsto/thread/31b1ffbf-117b-4e8f-ad38-71614437df59. If you have any feedbacks or suggestions on this FAQ, please feel free to write us emails to [e-mail].