selektovanje jednog (ili vise) itema u OpenFileDialog ...

Code:
SendMessage(listviewHandle, 0x0111/*WM_COMMAND*/, (uint)0x00017021, (uint)0);

Code:
SendMessage(listviewHandle, 0x0185/*LB_SETSEL*/, true, 1);

Code:
protected override void WndProc(ref Message m)
       {
             // Leting the Form take care off all messages.
            base.WndProc(ref m);

            if (m.Msg == 289) // Notify of message loop
            {
                uint dialogHandle = (uint)m.LParam; // Handle of the file dialog

                if (dialogHandle != m_lastDialogHandle) // Only when not already changed
                {
                    // Getting the handle of the ListBox in the OpenFileDialog dialog.
                    uint listviewHandle = FindWindowEx(dialogHandle, 0,
                    "SHELLDLL_DefView", "");

                    // Sending message to the ListBox to set the view to Thumbnails
                    //Icons=0x7029, List=0x702b, Details=0x702c, Thumbnails=0x702d,
                    //Tiles = 0x702e;
                    SendMessage(listviewHandle, 0x0111/*WM_COMMAND*/, (uint)0x702b, 0);

                    // Sending message to the ListBox to select all items.
                    uint retval = SendMessage(listviewHandle, 0x0111/*WM_COMMAND*/, (uint)0x00017021, (uint)0);
                    
                    // Remember last handle
                    m_lastDialogHandle = dialogHandle;

                }
           }

Code:
public partial class Form1 : Form
    {
        IntPtr h;
        int index = -1;

        private const long LVIS_STATEIMAGEMASK = 0xF000;
        private const long LVIS_UNCHECKED = 0x1000;
        private const long LVIS_CHECKED = 0x2000;
        private const long LVIF_STATE = 0x8;
        private const long LVM_FIRST = 0x1000;
        private const long LVM_SETITEMSTATE = (LVM_FIRST + 43);
        private const long LVIS_SELECTED = 0x2000;

        public Form1()
        {
            InitializeComponent();
            this.listView1.HideSelection = true;
            this.listView1.MultiSelect = true;
            h = this.listView1.Handle;
        }

        public struct LVITEM
        {
            public long mask;
            public long iItem;
            public long iSubItem;
            public long state;
            public long stateMask;
            public string pszText;
            public long cchTextMax;
            public long iImage;
            public long lParam;
            public long iIndent;
        }

        [DllImport("user32.dll")]
        private static extern uint SendMessage(IntPtr Hdc, long Msg_Const, int wParam, IntPtr lParam);


        private void button1_Click(object sender, EventArgs e)
        {
            LVITEM lvItem = new LVITEM();
            lvItem.mask = LVIF_STATE;
            lvItem.stateMask = LVIS_STATEIMAGEMASK;
            lvItem.state = LVIS_SELECTED;
            IntPtr pointer = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(LVITEM)));
            Marshal.StructureToPtr(lvItem, pointer, true);
            SendMessage(h, LVM_SETITEMSTATE, index, pointer);
            Marshal.FreeHGlobal(pointer);
        }
    }

Code:

//deo koda pre poziva SendMessage
unsafe{
  fix(void *p = pointer.ToPointer()){
    SendMessage(h, LVM_SETITEMSTATE, index, p);
  }
}
//pa ostatak