• exOLEDropEffectNone (0), Drop target cannot accept the data, or the drop operation was cancelled
• exOLEDropEffectCopy (1), Drop results in a copy of data from the source to the target. The original data is unaltered by the drag operation.
• exOLEDropEffectMove (2), Drop results in data being moved from drag source to drop source. The drag source should remove the data from itself after the move

The source component should logically Or together the supported values and places the result in the AllowedEffects parameter. The target component can use this value to determine the appropriate action (and what the appropriate user feedback should be).
You may wish to defer putting data into the ExDataObject object until the target component requests it. This allows the source component to save time.  If the user does not load any formats into the ExDataObject, then the drag/drop operation is canceled. 

// OLEStartDrag event is not supported. Use the DragEnter,DragLeave,DragOver, DragDrop ... events.

// OLEStartDrag event is not supported. Use the DragEnter,DragLeave,DragOver, DragDrop ... events.

private void OLEStartDrag(object sender, AxEXHTMLLib._IHTMLEvents_OLEStartDragEvent e)
{
}

void OnOLEStartDrag(LPDISPATCH Data,long FAR* AllowedEffects)
{
}

void __fastcall OLEStartDrag(TObject *Sender,Exhtmllib_tlb::IExDataObject *Data,long * AllowedEffects)
{
}

procedure OLEStartDrag(ASender: TObject; Data : IExDataObject;var AllowedEffects : Integer);
begin
end;

procedure OLEStartDrag(sender: System.Object; e: AxEXHTMLLib._IHTMLEvents_OLEStartDragEvent);
begin
end;

begin event OLEStartDrag(oleobject Data,long AllowedEffects)
end event OLEStartDrag

Private Sub OLEStartDrag(ByVal sender As System.Object, ByVal e As AxEXHTMLLib._IHTMLEvents_OLEStartDragEvent) Handles OLEStartDrag
End Sub

Private Sub OLEStartDrag(ByVal Data As EXHTMLLibCtl.IExDataObject,AllowedEffects As Long)
End Sub

Private Sub OLEStartDrag(ByVal Data As Object,AllowedEffects As Long)
End Sub

LPARAMETERS Data,AllowedEffects

PROCEDURE OnOLEStartDrag(oHTML,Data,AllowedEffects)
RETURN

<SCRIPT EVENT="OLEStartDrag(Data,AllowedEffects)" LANGUAGE="JScript">
</SCRIPT>

<SCRIPT LANGUAGE="VBScript">
Function OLEStartDrag(Data,AllowedEffects)
End Function
</SCRIPT>

Procedure OnComOLEStartDrag Variant llData Integer llAllowedEffects
	Forward Send OnComOLEStartDrag llData llAllowedEffects
End_Procedure

METHOD OCX_OLEStartDrag(Data,AllowedEffects) CLASS MainDialog
RETURN NIL

// OLEStartDrag event is not supported. Use the DragEnter,DragLeave,DragOver, DragDrop ... events.

function OLEStartDrag as v (Data as OLE::Exontrol.HTML.1::IExDataObject,AllowedEffects as N)
end function

function nativeObject_OLEStartDrag(Data,AllowedEffects)
return

To start accepting drag and drop sources the exGrid control should have the OLEDropMode to exOLEDropManual or exOLEDropAutomatic.

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

Private Sub HTML1_OLEStartDrag(ByVal Data As EXHTMLLibCtl.IExDataObject, AllowedEffects As Long)
    Dim s As String
    s = HTML1.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:

void OnOLEStartDragHTML1(LPDISPATCH Data, long FAR* AllowedEffects) 
{
	CString s( m_html.GetSelText() );
	if ( s.GetLength() > 0 )
	{
		*AllowedEffects = 1; /*exOLEDropEffectCopy*/
		if ( EXHTMLLib::IExDataObjectPtr spData( Data ) )
			spData->SetData( COleVariant( s ), COleVariant( long(EXHTMLLib::exCFText) ) );
		
	}
}

The C++ sample uses the #import <exhtml.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:

Private Sub AxHTML1_OLEStartDrag(ByVal sender As Object, ByVal e As AxEXHTMLLib._IHTMLEvents_OLEStartDragEvent) Handles AxHTML1.OLEStartDrag
    Dim s As String = AxHTML1.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:

private void axHTML1_OLEStartDrag(object sender, AxEXHTMLLib._IHTMLEvents_OLEStartDragEvent e)
{
	string s = axHTML1.SelText;
	if (s.Length > 0)
	{
		e.allowedEffects = 1;
		e.data.SetData(s, EXHTMLLib.exClipboardFormatEnum.exCFText );
	}
}

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

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

with thisform.HTML1
	local s
	s = .SelText
	if ( len(s) > 0 ) then 
		allowedeffects = 1
		data.SetData( s, 1 )
	endif
endwith