Completed
Last Updated: 09 Oct 2014 07:20 by ADMIN
To reproduce: 
public Form1()
        {
            InitializeComponent();

            Random r = new Random();
            DataTable table = new DataTable();
            table.Columns.Add("ID", typeof(int));
            table.Columns.Add("Name", typeof(string));
            table.Columns.Add("Bool", typeof(bool));
            table.Columns.Add("DateColumn", typeof(DateTime));

            for (int i = 0; i < 10; i++)
            {
                table.Rows.Add(i, "Row " + i, r.Next(10) > 5 ? true : false, DateTime.Now.AddHours(i));
            }

            radMultiColumnComboBox1.DataSource = table;
            radMultiColumnComboBox1.EditorControl.AutoSizeColumnsMode = Telerik.WinControls.UI.GridViewAutoSizeColumnsMode.Fill;
            
            radMultiColumnComboBox1.DropDownMinSize = new Size(500, 500);
        }

To work around:
            radMultiColumnComboBox1.DropDownOpening += new Telerik.WinControls.UI.RadPopupOpeningEventHandler(radMultiColumnComboBox1_DropDownOpening);

void radMultiColumnComboBox1_DropDownOpening(object sender, CancelEventArgs args)
{
    radMultiColumnComboBox1.MultiColumnComboBoxElement.MultiColumnPopupForm.MinimumSize =          new Size(500, 500);
}
Completed
Last Updated: 31 Jan 2017 10:31 by ADMIN
To reproduce, add RadMultiColumnCombobox on a form and use the following code:

  public Form1()
        {
            InitializeComponent();

            Random r = new Random();
            DataTable table = new DataTable();

            table.Columns.Add("ID", typeof(int));
            table.Columns.Add("Name", typeof(string));
            table.Columns.Add("Bool", typeof(bool));
            table.Columns.Add("DateColumn", typeof(DateTime));

            for (int i = 0; i < 10; i++)
            {
                table.Rows.Add(i, "Row " + i, r.Next(10) > 5 ? true : false, DateTime.Now.AddHours(i));
            }

            radMultiColumnComboBox1.DataSource = table;
            radMultiColumnComboBox1.DisplayMember = "Name";
            radMultiColumnComboBox1.AutoFilter = true;
            radMultiColumnComboBox1.DisplayMember = "Name";
            FilterDescriptor filter = new FilterDescriptor();
            filter.PropertyName = radMultiColumnComboBox1.DisplayMember;
            filter.Operator = FilterOperator.Contains;
            radMultiColumnComboBox1.EditorControl.MasterTemplate.FilterDescriptors.Add(filter);
        }

Once the form loads up, select the text in the editable area and enter any number from 0 to 9. It is important the width of the MCCB is smaller than the width the columns take.
Unplanned
Last Updated: 30 Mar 2016 09:31 by Svetlin
When filtering is applied to RadMultiColumnComboBox editor in CellEditorInitialized event of RadGridView, the selected item is second one, if the new row is edited.

Workaround: change the event handler by adding the following lines of code in the end of the RadGridView1_CellEditorInitialized:

Dim value As Object = e.Row.Cells(e.ColumnIndex).Value
 
If value Is Nothing Then
    editor.EditorControl.CurrentRow = Nothing
Else
    editor.Value = e.Row.Cells(e.ColumnIndex).Value
End If
Completed
Last Updated: 05 Jun 2014 07:08 by Svetlin
Shift + Tab navigation causes drop down opening of RadMultiColumnComboBox
Completed
Last Updated: 20 Apr 2012 04:35 by ADMIN
FIX. RadMultiColumnComboBox - when a row with null value is selected, instead of an empty string, the editor displays "Telerik.WinControls.UI.GridView"
Completed
Last Updated: 17 Apr 2012 07:45 by Svetlin
When auto filter is enabled and filtering is applied, you cannot select the correct item by mouse.
Completed
Last Updated: 30 May 2019 10:54 by ADMIN
Current item of RadMultiColumnComboBox is changed, when RadDock's document window position is changed.
Unplanned
Last Updated: 30 Mar 2016 09:29 by ADMIN
Workaround:

radMultiColumnComboBox1.DropDownOpening += new RadPopupOpeningEventHandler(radMultiColumnComboBox1_DropDownOpening);
....
 void radMultiColumnComboBox1_DropDownOpening(object sender, CancelEventArgs args)
        {
            int width = 0;
            foreach (GridViewDataColumn col in radMultiColumnComboBox1.EditorControl.Columns)
            {
                width += col.Width;
            }
            radMultiColumnComboBox1.MultiColumnComboBoxElement.MultiColumnPopupForm.MinimumSize = new Size(width, 0);
             
        }
Unplanned
Last Updated: 30 Mar 2016 09:26 by Svetlin
Completed
Last Updated: 14 Dec 2011 03:52 by Svetlin
The RadMultiColumnComboBox throws exceptions if its data source is empty and the AutoSizeDropDownToBestFit property is set to true.
Completed
Last Updated: 23 Nov 2011 10:59 by ADMIN
1. Create a new project with RadMultiColumnComboBox
2. Add rows in unbound mode
3. On a timer clear the Rows collection and insert new rows
4. Run the application and open and close the drop down several times
Completed
Last Updated: 12 Jul 2017 06:02 by ADMIN
1. Create a project with RadGridView
2. Add a GridViewMultiComboBoxColumn
3. Attach to CellEditorInitialized event and try to handle PopupOpened event to change the popup size.
Completed
Last Updated: 29 Jul 2014 13:20 by Svetlin
The SelectedValueChanged event is not fired when you select the current row after filtering.

Resolution: In Q1 2014 SP1 (2014.1.402) the first value from data source is selected by default and the event does not fire for already selected value.
If you select second or other value and after that select the first row, the SelectedValueChanged and SelectedIndexChanged are fired. 
Unplanned
Last Updated: 04 Sep 2018 09:30 by ADMIN
1. Create a new project and add RadMultiColumnComboBox
2. Bind it and setup filtering
3. Attach to SelectedValueChanged and SelectedIndexChanged events
4. Run the project
5. Apply some filtering and you will see that these events will not fire, regardless that the current row has changed.

Work around it by using the EditorControl.CurrentRowChanged event instead of SelectedValueChanged/SelectedIndexChanged events. 
Completed
Last Updated: 29 Jul 2011 05:33 by ADMIN
Using my two screenshots and values, note:
 1. Using Keyboard: I have 'A' selected and type a single 'W' to change my selection and hit enter. The next drop-down will still display at the width you see for the original A selection.  It will not be until the next drop-down that it resizes correctly.
 2. Using Mouse: I have 'A' selected and select the 'WWWW...." from the drop-down with my mouse.  The drop-down will appear correctly the next time.
Completed
Last Updated: 06 Apr 2011 04:32 by Svetlin
Current row is selected in RadMultiColumnComboBox when the mouse's left button is released.
Completed
Last Updated: 21 Mar 2011 07:21 by ADMIN
Set the AnimationEnabled property of RadCalendar and DropDownAnimationEnabled property in RadMultiColumnComboBox to false and there will be no effect.
Completed
Last Updated: 24 Nov 2010 08:07 by Svetlin
When auto-filtering is applied to RadMultiColumnComboBox and mouse double click is performed over a row, the selected row is changed to another row.
Completed
Last Updated: 11 Feb 2014 11:20 by ADMIN
FIX. RadMultiColumnComboBox. Setting the FormatString to a numeric column to some currency format and changing the column position results in displaying an invalid currency symbol.
Completed
Last Updated: 20 Sep 2010 12:17 by Svetlin
When you select a row by pressing the left mouse button twice, you will select a wrong row if RadMultiColumnComboBox has filter applied.