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.
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;
}
}
}
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);
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.
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