CheckedListBox.RemoveAt(lastItemIndex) causes a display issue in the list
I have a checkedlistbox that's bound to a generic list of custom type. When I remove other items on the list, the display is okay, but when I remove the last item on the list, the list shows up w/ the type name instead of the displayname.
_selResolutions.RemoveAt(selIndex);
cklResolutions.DataSource = null;
cklResolutions.BeginUpdate();
cklResolutions.DataSource = _selResolutions;
cklResolutions.DisplayMember = "LongDesc";
cklResolutions.Val开发者_C百科ueMember = "LongDesc";
cklResolutions.EndUpdate();
for (var i = 0; i < _selResolutions.Count; i++)
{
cklResolutions.SetItemChecked(i, _selResolutions[i].Selected);
}
the display looks like this when the last item is removed w/ the above code.
[ ] Resolution
[ ] Resolution
[ ] Resolution
[ ] Resolution
[ ] Resolution
why is this happening? am i missing something here? how do i correct this?
Try using a BindingSource instead. This provides the DataSource a view that can inform the DGV of changes:
using System;
using System.Collections.Generic;
using System.Windows.Forms;
class Form1 : Form
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
List<MyItem> _selResolutions;
CheckedListBox cklResolutions;
public Form1()
{
Controls.Add(cklResolutions = new CheckedListBox { Dock = DockStyle.Fill });
_selResolutions = new List<MyItem>();
_selResolutions.Add(new MyItem { LongDesc = "One", Selected = true });
_selResolutions.Add(new MyItem { LongDesc = "Two", Selected = false });
_selResolutions.Add(new MyItem { LongDesc = "Three", Selected = false });
_selResolutions.Add(new MyItem { LongDesc = "Four", Selected = true });
cklResolutions.DataSource = new BindingSource(_selResolutions, null);
cklResolutions.DisplayMember = cklResolutions.ValueMember = "LongDesc";
UpdateCheckBoxes();
cklResolutions.KeyUp += new KeyEventHandler(cklResolutions_KeyUp);
}
private void UpdateCheckBoxes()
{
for (int n = 0; n < _selResolutions.Count; n++)
cklResolutions.SetItemChecked(n, _selResolutions[n].Selected);
}
void cklResolutions_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Delete)
{
int index = cklResolutions.SelectedIndex;
if (index >= 0)
{
BindingSource bs = cklResolutions.DataSource as BindingSource;
bs.RemoveAt(index);
UpdateCheckBoxes();
}
}
}
}
class MyItem
{
public string LongDesc { get; set; }
public bool Selected { get; set; }
}
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