My music player uses ListView in Details mode to show tracks, and ListViewGroup to group albums tracks together.
I have created event that removes all tracks in one album, when album's ListViewGroup is middle-clicked. Works fine if ListView is not scrolled down when removing tracks. If ListView is scrolled down, album will be removed, but large non-clickable empty space appears at the top of ListView, between headers and first group.
First image, 3 albums in ListView (scrolled up)
Second image, last album removed, everything's fine!
Ok, then ListView is scrolled down when removing one group of items
Third image, 3 albums in ListView (scrolled down)
Fourth image, last album removed, empty space appeared at the top, and last tracks if ListView is not showing at all!
I don't think this has anything to do with my code, but rather a bug in ListView? Anyone noticed same behavior? Is there any trick to prevent this from happening?
EDIT: added code which removes items (as user requested it)
List<ListViewItem> delItems = new List<ListViewItem>(); // creating list of items to be removed
foreach (ListViewGroup group in listView1.Groups)
{
if (Convert.ToInt32(group.Tag) == groupNumber) // all groups have individual number in tag field
{
foreach (ListViewItem item in group.Items)
{
delItems.Add(item);
}
}
}
foreach (ListViewItem item in delItems)
{
item.Remove();
}
EDIT2: added code to check if group was clicked
Since there is no real way to handle group click, I made it ugly way. But it works. First of all, I used MouseDown event in ListView. Then I check whether there is an item where user clicks. If user clicks group, then the item is null, and for loop increases i and checks if item can be found now. When eventually item found, we know that the item belongs to the group we clicked. So we get items group tag, where I keep record of what group it is.
private void listView1_MouseDown(object sender, MouseEventArgs e)
{
ListViewItem item;
for (int i = 0; i < 25; i++) // group height is not more that 25 pixels.
{
item = listView1.GetItemAt(e.X, e.Y + i);
if (item != null)
{
if (i > 1) // bigger than 1, because there is 1 pixel gap between listviewitems when using groups
{
if (e.Button == MouseButtons.Middle) removePlaylistGroup(Convert.ToInt32(item.Group.Tag));
}
else
{
if (e.Button == MouseButtons.Middle) removePlaylistItem(item.Index);
}
break;
}
}
}