Hello, we have found another small bug of the RadVirtualGrid control.

When paging is enabled on child view, one of the component of the paging panel overlap whit is parent.

I attach source code and screenshot.

 

Thanks in advance.

 

To reproduce: please refer to the attached gif file. The CellClick is not fired for the child rows that belong to columns that exceed the width of the parent template.

Workaround: set the AutoSizeColumnsMode property to Fill.

this.radVirtualGrid1.AutoSizeColumnsMode = Telerik.WinControls.UI.VirtualGridAutoSizeColumnsMode.Fill;

Please run the attached sample project and follow the steps from the gif file.

When you setup a hierarchical RadVirtualGrid and set the UseScrollbarsInHierarchy property to false and use VirtualGridAutoSizeColumnsMode.Fill for the child template, you expect that the column's width is calculated according to the total width of the respective template. Hence, if you shrink or enlarge the grid, the columns will shrink/enlarge respectively. However, if you double click the resize cursor between the column headers you will notice that the best-fit action is performed over the column and its width is adjusted. However, the VirtualGridAutoSizeColumnsMode.Fill setting is not respected and you either can't see all the columns, or you obtain some empty space if the column doesn't need much space. 

To reproduce: open the Demo application >> VirtualGrid >> First Look example. Follow the steps illustrated in the attached gif file. You will notice that when you expand a row, the "-" sign is show for a second and then it is returned to "+" although the row is still expanded. 

Workaround:
            this.radVirtualGrid1.CellFormatting += radVirtualGrid1_CellFormatting;
            this.radVirtualGrid1.RowExpanded += radVirtualGrid1_RowExpanded;
            this.radVirtualGrid1.RowCollapsed += radVirtualGrid1_RowCollapsed;



        private void radVirtualGrid1_RowCollapsed(object sender, VirtualGridRowExpandedEventArgs e)
        {
            if (expandedState.ContainsKey(e.RowIndex))
            {
                expandedState[e.RowIndex] = !expandedState[e.RowIndex];
            }
           
            this.radVirtualGrid1.TableElement.SynchronizeRow(e.RowIndex, true);
        }

        Dictionary<int, bool> expandedState = new Dictionary<int, bool>();

        private void radVirtualGrid1_RowExpanded(object sender, VirtualGridRowExpandedEventArgs e)
        {
            if (!expandedState.ContainsKey(e.RowIndex))
            {
                expandedState.Add(e.RowIndex, false);
            }
            expandedState[e.RowIndex] = !expandedState[e.RowIndex];
            this.radVirtualGrid1.TableElement.SynchronizeRow(e.RowIndex, true);
        }

        private void radVirtualGrid1_CellFormatting(object sender, Telerik.WinControls.UI.VirtualGridCellElementEventArgs e)
        {
            VirtualGridIndentCellElement indentCell = e.CellElement as VirtualGridIndentCellElement;
            if (indentCell != null)
            {
                if (expandedState.ContainsKey(e.CellElement.RowIndex) && expandedState[e.CellElement.RowIndex] == true)
                {
                    indentCell.ExpanderItem.SignImage = Properties.Resources.chevron_up;
                }
                else
                {
                    indentCell.ExpanderItem.SignImage = Properties.Resources.chevron_down;
                }
            }

        }

RadVirtualGrid shold automatically adjust the height of the visible cells/rows only. When you perform scrolling horizontally or vertically, the respective scrollbar will be adjusted. The scrollbar may shrink or enlarge considering the currently displayed data. Have in mind that when you have a horizontal scrollbar, the row's height will be calculated according to the content of the visible cells on the row. If you scroll horizontally and some of the cells on the row get hidden and others get visible, the row's height should be adjusted according to the content. Initially, this behavior may be confusing for the users, however since data is loaded on demand in RadVirtualGrid, you need to autosize the rows on demand as well. 

To reproduce: if you set the TableElement.RowHeight property, it affects the header row as well, but not all cells. As a result the header row overlaps the new row.

Workaround: set the TableElement.HeaderRowHeight as well.

  this.radVirtualGrid1.TableElement.HeaderRowHeight = 50;

It is difficult to replicate the issue and it is not always reproduced. When using the splitter between columns[1] and columns[2]  to resize column[1] I found out that releasing the mouse button doesn't cause the splitter to be released, even when clicking on the grid. It seems to work ok once or twice but once it fails then keeps failing.

Workaround:
        private void radVirtualGrid1_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == System.Windows.Forms.MouseButtons.Left)
            {
                this.radVirtualGrid1.Cursor = Cursors.Default;
            }
        }

To reproduce: use the following code snippet. Navigate to the last page and press the button to clear the rows. You will notice that the current page index remains 10 although no rows are available in the grid

        public RadForm1()
        {
            InitializeComponent();

            this.radVirtualGrid1.RowCount = 1000;
            this.radVirtualGrid1.ColumnCount = 5;
            this.radVirtualGrid1.CellValueNeeded += radVirtualGrid1_CellValueNeeded;

            this.radVirtualGrid1.EnablePaging = true;
        }

        private void radVirtualGrid1_CellValueNeeded(object sender, Telerik.WinControls.UI.VirtualGridCellValueNeededEventArgs e)
        {
            e.Value = "Item" + e.RowIndex + "." + e.ColumnIndex;
        }

        private void radButton1_Click(object sender, EventArgs e)
        {
            this.radVirtualGrid1.RowCount = 0;
            this.radVirtualGrid1.ColumnCount = 5; 
        }

Workaround:  this.radVirtualGrid1.VirtualGridElement.FindDescendant<VirtualGridPagingPanelElement>().PageNumberTextBox.Text = "1";

To reproduce: open the VirtualGrid >> First Look example in QSF and follow the steps:

1) I have a virtual grid which has both vertical and horizontal scroll bars.

2) Scroll to the very bottom of the grid

3) Select the last row

4) Scroll all the way to the right

At this moment the selected row disappears from the view. While scrolling horizontally the vertical scrollbar jumps several rows above although it seems scrolled to the bottom. 

To reproduce: run the sample project and try to resize some of the columns.

RadVirtualGrid has 10 columns and 500 rows. You will notice the laggind while resizing the columns. Actually the number of the visible cells remains the same after the column's resizing. However, the CellValueNeeded event keeps firing.

A newly created grid has its CurrentCell property initialized to Nothing. Pressing [PageDown] or any other key that causes scrolling will crash.

Steps to Reproduce:
1. Launch application
2. Press [PageDown]

 Sub New() 
        InitializeComponent()

        Me.RadVirtualGrid1.ColumnCount = 50
        Me.RadVirtualGrid1.RowCount = 100
        AddHandler Me.RadVirtualGrid1.CellValueNeeded, AddressOf RadVirtualGrid1_CellValueNeeded
    End Sub

    Private Sub RadVirtualGrid1_CellValueNeeded(sender As Object, e As Telerik.WinControls.UI.VirtualGridCellValueNeededEventArgs)
        e.Value = e.ColumnIndex
    End Sub

Workaround: 

Me.RadVirtualGrid1.CurrentCell = New Telerik.WinControls.UI.VirtualGridCellInfo(0, 0, Me.RadVirtualGrid1.MasterViewInfo)

I miss grouping functionality in VirtualGrid. In my opinion, the following process would be conceivable:
1. user interaction triggers an event - e. g. GroupChanged (similar to FilterChanged).
2. This event determines all available groups and returns them to the VirtualGrid. 
3. if the user expand a group > a second event is fired - and returns all matching data rows.

To reproduce:
- Enable the paging and add 1000 rows.
- Press Ctrl + End
- An exception is thrown.

Workaround:

radVirtualGrid1.VirtualGridElement.InputBehavior = new MyBehavior(radVirtualGrid1.VirtualGridElement);

class MyBehavior : VirtualGridInputBehavior
{
    public MyBehavior(RadVirtualGridElement element) : base(element)
    {

    }
    protected override bool HandleEndKey(KeyEventArgs keys)
    {
        this.GridElement.PageIndex = this.GridElement.TotalPages - 1;
      
        return true;
        //return base.HandleEndKey(keys);
    }
}

The attached gif file illustrates how to reproduce the problem with the Demo application. 

Use attached to reproduce (just start it and press enter).

Workaround:

class MyBehavior : VirtualGridInputBehavior
{
    public MyBehavior(RadVirtualGridElement element) : base(element)
    {

    }
    protected override bool HandleEnterKey(KeyEventArgs keys)
    {
        if (this.GridElement.CurrentCell != null)
        {
            return base.HandleEnterKey(keys);
        }
        return false; 
    }
}


radVirtualGrid1.VirtualGridElement.InputBehavior = new MyBehavior(radVirtualGrid1.VirtualGridElement);

Workaround:
this.radVirtualGrid1.RowCount += 100;
this.radVirtualGrid1.TableElement.PagingPanelElement.UpdateView();

To reproduce:
void radButton1_Click(object sender, EventArgs e)
{
    this.radVirtualGrid1.CurrentCell = null;
}

Workaround:

class MyRadVirtualGrid : RadVirtualGrid
{
    protected override void CreateChildItems(RadElement parent)
    {
        base.CreateChildItems(parent);
        parent.Children.RemoveAt(0);
        var field = typeof(RadVirtualGrid).GetField("virtualGridElement", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
        var element = new MyVirtualGridElement();
        field.SetValue(this,element);

        
        parent.Children.Add(element);
    }
}
class MyVirtualGridElement : RadVirtualGridElement
{
    protected override Type ThemeEffectiveType
    {
        get { return typeof(RadVirtualGridElement); }
    }
    protected override bool SetCurrentCell(VirtualGridCellInfo value)
    {
        if (value == null)
        {
            if (this.IsInEditMode && !this.EndEdit())
            {
                return false;
            }

            int row = int.MinValue;
            VirtualGridViewInfo viewInfo = null;

            if (this.CurrentCell != null)
            {
                row = this.CurrentCell.RowIndex;
                viewInfo = this.CurrentCell.ViewInfo;
            }

            if (this.CurrentCell != null && (value == null || this.CurrentCell.ViewInfo != value.ViewInfo || this.CurrentCell.RowIndex != value.RowIndex))
            {
                VirtualGridRowValidatingEventArgs e = new VirtualGridRowValidatingEventArgs(row, viewInfo);
                this.OnRowValidating(e);

                if (e.Cancel)
                {
                    return false;
                }
            }
            var currentCell = typeof(RadVirtualGridElement).GetField("currentCell", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
            currentCell.SetValue(this, value);

            if (this.CurrentCell != null)
            {
                this.EnsureCellVisible(this.CurrentCell.RowIndex, this.CurrentCell.ColumnIndex, this.CurrentCell.ViewInfo);
            }

            VirtualGridTableElement tableElement = null;

            if (this.CurrentCell != null)
            {
                tableElement = this.GetTableElement(this.CurrentCell.ViewInfo);
            }
            else
            {
                tableElement = this.TableElement;
            }
            

            if (tableElement != null)
            {
                VirtualGridRowElement rowElement = tableElement.ViewElement.GetRowElement(row);

                if (rowElement != null)
                {
                    rowElement.Synchronize(false);
                }
            }

            if (value != null)
            {
                tableElement = this.GetTableElement(value.ViewInfo);
                if (tableElement != null)
                {
                    VirtualGridRowElement rowElement = tableElement.ViewElement.GetRowElement(value.RowIndex);

                    if (rowElement != null)
                    {
                        rowElement.Synchronize(false);
                    }
                }
            }

            if (viewInfo != null)
            {
                VirtualGridRowEventArgs args = new VirtualGridRowEventArgs(row, viewInfo);
                this.OnRowValidated(args);
            }

            this.OnCurrentCellChanged(EventArgs.Empty);

            return true;
        }
        return base.SetCurrentCell(value);
    }
}