Adding a select all shortcut (Ctrl + A) to a .net listview?

Question

Like the subject says I have a listview, and I wanted to add the Ctrl + A select all shortcut to it. My first problem is that I can\'t figure out how

Answer 1

These works for small lists, but if there are 100,000 items in a virtual list, this could take a long time. This is probably overkill for your purposes, but just in case::

class NativeMethods {
    private const int LVM_FIRST = 0x1000;
    private const int LVM_SETITEMSTATE = LVM_FIRST + 43;

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct LVITEM
    {
        public int mask;
        public int iItem;
        public int iSubItem;
        public int state;
        public int stateMask;
        [MarshalAs(UnmanagedType.LPTStr)]
        public string pszText;
        public int cchTextMax;
        public int iImage;
        public IntPtr lParam;
        public int iIndent;
        public int iGroupId;
        public int cColumns;
        public IntPtr puColumns;
    };

    [DllImport("user32.dll", EntryPoint = "SendMessage", CharSet = CharSet.Auto)]
    public static extern IntPtr SendMessageLVItem(IntPtr hWnd, int msg, int wParam, ref LVITEM lvi);

    /// 

    /// Select all rows on the given listview
    /// 
    /// The listview whose items are to be selected
    public static void SelectAllItems(ListView list) {
        NativeMethods.SetItemState(list, -1, 2, 2);
    }

    /// 

    /// Deselect all rows on the given listview
    /// 
    /// The listview whose items are to be deselected
    public static void DeselectAllItems(ListView list) {
        NativeMethods.SetItemState(list, -1, 2, 0);
    }

    /// 

    /// Set the item state on the given item
    /// 
    /// The listview whose item's state is to be changed
    /// The index of the item to be changed
    /// Which bits of the value are to be set?
    /// The value to be set
    public static void SetItemState(ListView list, int itemIndex, int mask, int value) {
        LVITEM lvItem = new LVITEM();
        lvItem.stateMask = mask;
        lvItem.state = value;
        SendMessageLVItem(list.Handle, LVM_SETITEMSTATE, itemIndex, ref lvItem);
    }
}

and you use it like this::

NativeMethods.SelectAllItems(this.myListView);