C#

Pete O`Hanlon wrote:

Why would you want to do this? This is the "holy grail" for virus writers.

private struct NMHDR
{
    IntPtr hwndFrom;
    IntPtr idFrom;
    UInt32 code;
}

//Check to see if it is a WM_NOTIFY msg
if (m.Msg == WM_NOTIFY)
{
    //Convert the lParam (within m) to NMHDR struct
}

//Check to see if it is a WM_NOTIFY msg
if (m.Msg == WM_NOTIFY)
{
    NMHDR nmHdr = new NMHDR();
    nmHdr = (NMHDR)m.GetLParam(typeof(NMHDR));
    if (nmHdr.code == NM_CUSTOMDRAW)
    {
        Debug.WriteLine("Got here.");
    }
}

nmlvCust = (NMLVCUSTOMDRAW)m.GetLParam(typeof(NMLVCUSTOMDRAW));

Marshal.StructureToPtr(nmlvCust, m.LParam, true);

David Fleming wrote:

Boy, I hope you're not getting irritated with this thread yet because I like learning stuff.

David Fleming wrote:

I'm just wondering if you've ever actually attempted what I'm talking about here. Your original response, and the associated links, made it seem as though this might be fairly easy. Unfortunately, the more I learn about it, the harder it seems to be getting.

[StructLayout(LayoutKind.Sequential)]
struct NMLVCUSTOMDRAW
{
  NMCUSTOMDRAW customDraw;
  int textColor;
  int textBackColor;
  int subItemIndex;
  //**From here on, the members are only declared for Common Controls 6
  // - Windows XP and up! Therefore, if they are included, you can only
  //use this struct on XP and above!**
  uint itemType;
  int faceColor;
  //You may want to define the following 4 as enum values for ease of use
  int iconEffect;
  int iconPhase;
  int partID;
  int stateID;
  RECT textRect;
  uint groupAlignment;
}

protected override void WndProc(ref System.Windows.Forms.Message m)
{
    //Always perform default functionality
    base.WndProc(ref m);

    //Check to see if it is a WM_NOTIFY msg
    if (m.Msg == WM_NOTIFY)
    {
        //NMHDR nmHdr = new NMHDR();
        //nmHdr = (NMHDR)m.GetLParam(typeof(NMHDR));
        nmlvCust = (NMLVCUSTOMDRAW)m.GetLParam(typeof(NMLVCUSTOMDRAW));
        if (nmlvCust.nmcd.hdr.code == NM_CUSTOMDRAW)
        {
            //Have windows do default drawing in case we don't make any changes
            m.Result = (IntPtr)CDRF_DODEFAULT;
            Debug.WriteLine("In CustomDraw. dwDrawStage = " + nmlvCust.nmcd.dwDrawStage  ". Result = " + m.Result);


            if (nmlvCust.nmcd.dwDrawStage == CDDS_PREPAINT)
            {
                //We will notify windows that we want messages for each item
                m.Result = (IntPtr)CDRF_NOTIFYITEMDRAW;
                Debug.WriteLine("In PrePaint. dwDrawStage = " + nmlvCust.nmcd.dwDrawStage + ". Result = " + m.Result);
            }
            else if (nmlvCust.nmcd.dwDrawStage == CDDS_ITEMPREPAINT)
            {
                //We will notify windows that we want messages for each subitem
                m.Result = (IntPtr)CDRF_NOTIFYSUBITEMDRAW;
                Debug.WriteLine("In ItemPrePaint. dwDrawStage = " + mlvCust.nmcd.dwDrawStage + ". Result = " + m.Result);
            }
            else if (nmlvCust.nmcd.dwDrawStage == (CDDS_ITEMPREPAINT | CDDS_SUBITEM))
            {
                //Here's where we do our stuff
                if (nmlvCust.iSubItem == 0)
                {
                    nmlvCust.clrText = ColorTranslator.ToWin32(SystemColors.Control);
                    nmlvCust.clrTextBk = ColorTranslator.ToWin32(SystemColors.Info);
                }
                else if (nmlvCust.iSubItem == 1)
                {
                    nmlvCust.clrText = ColorTranslator.ToWin32(SystemColors.WindowText);
                    nmlvCust.clrTextBk = ColorTranslator.ToWin32(SystemColors.Window);
                }
                else //if (nmlvCust.iSubItem == 2)
                {
                    nmlvCust.clrText = ColorTranslator.ToWin32(SystemColors.HighlightText);
                    nmlvCust.clrTextBk = ColorTranslator.ToWin32(SystemColors.Highlight);
                }
                m.Result = (IntPtr)CDRF_NOTIFYSUBITEMDRAW;
                Debug.WriteLine("In SubItem. dwDrawStage = " + nmlvCust.nmcd.dwDrawStage + ". Result = " + m.Result);
            }
        }

        Marshal.StructureToPtr(nmlvCust, m.LParam, true);
    }
}

// flags are the same, we can distinguish by context

if(e.KeyData == Keys.Tab)
{
	e.Handled = true;  //prevents that Tab is pressed
}