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 to programmatically select all items in a listview. It seems like it should be relatively easy, like ListView.SelectAll() or ListView.Items.SelectAll(), but that doesn't appear to be the case. My next problem is how to define the keyboard shortcut for the ListView. Do I do it in a KeyUp event, but then how would you check two presses at once? Or is it a property that you set?

Any help here would be great.

Shane Fulmer · Accepted Answer · 2010-02-25T14:54:07.277

32

You could accomplish both with something like this:

private void listView1_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.A && e.Control)
    {
        listView1.MultiSelect = true;
        foreach (ListViewItem item in listView1.Items)
        {
            item.Selected = true;
        }
    }
}

edited Feb 25 '10 at 14:54

answered Jun 19 '09 at 18:36

Shane Fulmer

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Ha, I knew it was going to be something ridiculously easy. Thanks. – ryanulit Jun 19 '09 at 18:39
7

I had the problem when using CTRL+A the listbox would jump to the first "A" item after selecting all. (Leaving only one item selected.) Adding `e.SuppressKeyPress = true;` after the loop solved this. – JYelton Mar 26 '12 at 21:17
For large lists, one should suspend update. https://stackoverflow.com/q/15398091/340790 – JdeBP Feb 04 '21 at 13:18
In 2022 with VS2022 this still works. Thanks! – Jelle Schräder Feb 14 '22 at 15:13
`e.KeyCode == Keys.A && e.Control` didn't work for me, it cought event on the second pressing of the keys (I don't know why), but the condition listed below worked fine: `e.KeyData == (Keys.A | Keys.Control)` – Dalibor Apr 06 '22 at 15:05

score 26 · Answer 2 · answered Jul 13 '09 at 09:03

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);

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

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

    /// <summary>
    /// Set the item state on the given item
    /// </summary>
    /// <param name="list">The listview whose item's state is to be changed</param>
    /// <param name="itemIndex">The index of the item to be changed</param>
    /// <param name="mask">Which bits of the value are to be set?</param>
    /// <param name="value">The value to be set</param>
    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);

Are there any prerequisites to getting this code to run? I'm trying it on a regular .NET ListView with CheckBoxes = true. And it's not doing anything. — Esteban Brenes, Sep 30 '10 at 05:28
Thanks a lot, this works great! I use a listview in virtual mode. But somehow the number of items seems to be limited. Are you sure 100.000 rows are possible? — brighty, Oct 24 '14 at 12:34
There is an upper limit of 9,999,999. See this answer: http://stackoverflow.com/a/2462211/106008 — Grammarian, Oct 28 '14 at 00:13
Is there a version of this that works with setting the "checked" state of every list view item for a "check all" and "uncheck all" scenario? — Grungondola, May 10 '16 at 15:54
You don't need to implement deselect yourself; there's a built-in `SelectedIndices.Clear()` method. Internally it does the same thing as this. — Billy, Feb 07 '20 at 00:58
This is amazing. In a ListView with 143k entries the time to select all items with this method compared to the foreach method went down from 69 s to 0.3 s. — cad, Jul 16 '22 at 20:04

score 7 · Answer 3 · answered Aug 22 '13 at 09:34

7

private void listView1_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyData == (Keys.A | Keys.Control))
        foreach (ListViewItem item in listView1.Items)
            item.Selected = true;
}

To only do it on Ctrl+A, not on other combinations like Ctrl+Shift+A etc.

answered Aug 22 '13 at 09:34

nyrocron

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+1 for point "To only do it on Ctrl+A", Grammarian's solution is better for performance though – yclkvnc Oct 02 '14 at 08:07
For large lists, one should suspend update. https://stackoverflow.com/q/15398091/340790 – JdeBP Feb 04 '21 at 13:19

score 3 · Answer 4 · edited Sep 10 '11 at 11:31

3

The first solution won't work if user releases the Ctrl key first.

You should use the KeyDown event instead:

private void listView1_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.A && e.Control)
    {
        listView1.MultiSelect = true;
        foreach (ListViewItem item in listView1.Items)
        {
            item.Selected = true;
        }
    }
}

edited Sep 10 '11 at 11:31

Jasper

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answered Dec 15 '09 at 15:03

olorin

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I was not able to post a comment on first answer so I posted a new answer (sorry about that) – olorin Dec 15 '09 at 15:05
This doesn't seem to be any different from the first answer (except the order of chcks in the if statement). Am I missing something? – Samik R Nov 08 '11 at 22:41

score 0 · Answer 5 · answered Jul 06 '13 at 13:23

I could not comment on the first question, however solution with KeyDown does not work for me, because system immediately reacts on LeftCtrl pressed and so skips CTRL+A. From other side KeyUp works correctly.

private void listView1_KeyUp(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.A && e.Control)
    {
        listView1.MultiSelect = true;
        foreach (ListViewItem item in listView1.Items)
        {
            item.Selected = true;
        }
    }
}

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

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