The ExExpression control supports manual or automatic OLE Drag and Drop operation. The control fires the OLEStartDrag when the user starts OLE drag and drop operation.

The following VB sample puts the selected text to the clipboard when the drag and drop operation starts ( The OLEDropMode property is exOLEDropAutomatic ):

With Expression1
    .OLEDropMode = exOLEDropManual
End With

Private Sub Expression1_OLEStartDrag(ByVal Data As EXPRESSIONLibCtl.IExDataObject, AllowedEffects As Long)
    Dim s As String
    s = Expression1.SelText
    If (Len(s) > 0) Then
        AllowedEffects = 1
        Data.SetData s, 1
    End If
End Sub

The following C++ sample puts the selected text to the clipboard when the drag and drop operation starts:

m_expression.SetOLEDropMode( 1 );

void OnOLEStartDragExpression1(LPDISPATCH Data, long FAR* AllowedEffects) 
{
	CString s( m_expression.GetSelText() );
	if ( s.GetLength() > 0 )
	{
		*AllowedEffects = 1; /*exOLEDropEffectCopy*/
		if ( EXPRESSIONLib::IExDataObjectPtr spData( Data ) )
			spData->SetData( COleVariant( s ), COleVariant( long(EXPRESSIONLib::exCFText) ) );
		
	}
}

The C++ sample uses the #import <expression.dll> statement to include definitions for the IExDataObject and IExDataObjectFiles objects.

The following VB.NET sample puts the selected text to the clipboard when the drag and drop operation starts:

With AxExpression1
    .OLEDropMode = EXPRESSIONLib.exOLEDropModeEnum.exOLEDropManual
End With

Private Sub AxExpression1_OLEStartDrag(ByVal sender As Object, ByVal e As AxEXPRESSIONLib._IExpressionEvents_OLEStartDragEvent) Handles AxExpression1.OLEStartDrag
    Dim s As String = AxExpression1.SelText
    If (Len(s) > 0) Then
        e.allowedEffects = 1
        e.data.SetData(s, 1)
    End If
End Sub

The following C# sample puts the selected text to the clipboard when the drag and drop operation starts:

axExpression1.OLEDropMode = EXPRESSIONLib.exOLEDropModeEnum.exOLEDropManual;

private void axExpression1_OLEStartDrag(object sender, AxEXPRESSIONLib._IExpressionEvents_OLEStartDragEvent e)
{
	string s = axExpression1.SelText;
	if (s.Length > 0)
	{
		e.allowedEffects = 1;
		e.data.SetData(s, EXPRESSIONLib.exClipboardFormatEnum.exCFText );
	}
}

The following VFP sample puts the selected text to the clipboard when the drag and drop operation starts:

with thisform.Expression1
	.OLEDropMode = 1
endwith

*** ActiveX Control Event ***
LPARAMETERS data, allowedeffects

with thisform.Expression1
	local s
	s = .SelText
	if ( len(s) > 0 ) then 
		allowedeffects = 1
		data.SetData( s, 1 )
	endif
endwith