Customize editor of GridViewMultiComboBoxColumn throw cast exception

[Le]

Hi Telerik Team 

I customize to inherit GridViewMultiComboBoxColumn, BaseGridBehavior and RadMultiColumnComboBox. Example MeGridBehavior (inherited form BaseGridBehavior), MeGridViewMultiComboBoxColumn(inherited form GridViewMultiComboBoxColumn), MeMultiColumnComboBox (inherited form RadMultiColumnComboBox), MeMultiColumnComboBoxElement (inherit RadMultiColumnComboBoxElement)

when init GridView i set this.GridBehavior = new MeGridBehavior(), if column is Combobox editor i create MeGridViewMultiComboBoxColumn column and i  override event  OnEditorRequired and CreateMultiColunmnComboboxElement ;

//On MeMultiColumnCombobox
protected override RadMultiColumnComboBoxElement CreateMultiColumnComboBoxElement()
{
    return new MeMultiColumnComboBoxElement(this.Name,this);
}

// on GridView
protected override void OnEditorRequired(object sender, EditorRequiredEventArgs e)
{
    if (this.CurrentColumn is MeGridViewMultiComboBoxColumn)
    {
        var column = this.CurrentColumn as MeGridViewMultiComboBoxColumn;
     MeMultiColumnComboBox cbx= CreateDataComboBox("Countries");
      e.Editor = cbx.MeMultiColumnComboBoxElement;
    }
}

protected override void OnCellValidating(object sender, CellValidatingEventArgs e)
{
    //if value not in list of countries ?
    var cbxCol = e.Column as MeGridViewMultiComboBoxColumn;
    var detectError = ComboBoxValidating(text, e);
    if (detectError)
    {
        e.Cancel = true;
        base.OnCellValidating(sender,e);
        ShowValidateError();
        return;
    }
}

When i click to another cell it throw exeption on mouseup event of MeGridBehavior 

Unable to cast object of type 'MeMultiColumnComboBoxElement' to type 'Telerik.WinControls.UI.BaseGridEditor'.

   at Telerik.WinControls.UI.GridViewEditManager.EndEditCore(Boolean validate, Boolean cancel)
   at Telerik.WinControls.UI.GridViewEditManager.CloseEditor()
   at Telerik.WinControls.UI.RadGridViewElement.CloseEditor()
   at Telerik.WinControls.UI.GridRowBehavior.OnMouseUpLeft(MouseEventArgs e)
   at Telerik.WinControls.UI.GridRowBehavior.OnMouseUp(MouseEventArgs e)
   at Telerik.WinControls.UI.BaseGridBehavior.OnMouseUp(MouseEventArgs e)
   at ......OnMouseUp(MouseEventArgs e) in d:\\MeProject\GridView\MeGridViewBehavior.cs

This error throw when I update to telerik rad control winforms version Q3 2013  but it work with version Q1 2013

Any one can help me ! 
Thanks .

[Dess | Tech Support Engineer, Principal]

Hello Le,

Thank you for contacting Telerik Support.

This is a known issue, concerning our GridViewMultiComboBoxColumn. We have it logged in our Public Issue Tracking System - PITS. You can track its progress, subscribe for status changes and add your vote/comment to it on the following link - PITS issue.

Currently, the possible workaround that I can suggest is to set EditorManager.CloseEditorWhenValidationFails to true:

radGridView1.EditorManager.CloseEditorWhenValidationFails = true;

I hope this information helps. Should you have further questions, I would be glad to help.

Regards,
Desislava
Telerik

[Le]

Hello Desislava.
Thank you very much about support.
Your suggest help for me pass error and not throw exception , but, as you see in my code , onCellFormating event i want if value not in list i will show message and pointer must focus at current cell for end user type new value or select one value in my combobox editor, So, i set  
 CloseEditorWhenValidationFails =true   pointer focus to another cell. Can you help me If you have any idea about my issue,

Thanks .
        

[Dess | Tech Support Engineer, Principal]

Hello Le,

Thank you for contacting us again.

I can suggest an alternative solution for the GridViewMultiComboBoxColumn cancelling validation without changing the current focus to the next cell. The sample code uses a custom RadGridView:

private void Form1_Load(object sender, EventArgs e)
{
    this.categoriesTableAdapter.Fill(this.northwindDataSet.Categories);
}

private void radGridView1_CellValidating(object sender, CellValidatingEventArgs e)
{
    int valueToCancel = 0;
    if (e.Column is GridViewMultiComboBoxColumn && e.ActiveEditor != null && e.ActiveEditor.Value != null)
    {
        if (int.TryParse(e.ActiveEditor.Value.ToString(), out valueToCancel) && valueToCancel == 1)
        {
            e.Cancel = true;
            MessageBox.Show("failed");
        }
    }
}

public class CustomGrid : RadGridView
{
    protected override RadGridViewElement CreateGridViewElement()
    {
        return new CustomGridElement();
    }
}

public class CustomGridElement : RadGridViewElement
{
    protected override GridViewEditManager CreateEditorManager()
    {
        return new CustomEditManager(this);
    }
}

public class CustomEditManager : GridViewEditManager
{
    public CustomEditManager(RadGridViewElement gridViewElement) : base(gridViewElement)
    {
    }

    protected override bool EndEditCore(bool validate, bool cancel)
    {
        GridCellElement cell = this.GridViewElement.CurrentView.CurrentCell;
        bool validated = true;

        if (validate)
        {
            this.GridViewElement.TableElement.BeginUpdate();
            validated = !RaiseCellValidatingEvent(cell.RowInfo, cell.ColumnInfo,
                this.ActiveEditor.Value, cell.Value);
            this.GridViewElement.TableElement.EndUpdate(false);
            if (!validated && !CloseEditorWhenValidationFails)
            {
                BaseGridEditor baseGridEditor = this.ActiveEditor as BaseGridEditor;
                RadElement element = null;
                if (baseGridEditor == null)
                {
                    element = this.ActiveEditor as RadElement;
                }
                else
                {
                    element = baseGridEditor.EditorElement;
                }

                RadTextBoxItem textBoxItem = element != null ? element.FindDescendant<RadTextBoxItem>() : null;

                if (textBoxItem != null)
                {
                    textBoxItem.HostedControl.Focus();
                }

                return validated;
            }
            else
            {
                validate = false;
            }
        }
        return base.EndEditCore(validate, cancel);
    }

    private bool RaiseCellValidatingEvent(GridViewRowInfo row, GridViewColumn column,
        object newValue, object oldValue)
    {
        CellValidatingEventArgs cellValidating = new CellValidatingEventArgs(row,
            column, newValue, oldValue, ActiveEditor);
        this.GridViewElement.Template.EventDispatcher.RaiseEvent<CellValidatingEventArgs>
            (EventDispatcher.CellValidating, this, cellValidating);
        return cellValidating.Cancel;
    }
}

Please do not hesitate to contact us if you have any additional questions.

Regards,
Desislava
Telerik

[Le]

Thanks Desislava and Telerik team very much .It's really very helpfull for me.
Best regard!