Under Review
Last Updated: 17 Jul 2019 14:00 by ADMIN

Using a custom control using the Telerik Presentation Framework, I am receiving a NullException inside the GridCheckBoxHeaderCellElement during the GridViewElement's data load.

The custom control construction follows an example I found somewhere (reference is lost to me at this point):

ControlContainingGridView inherits from RadControl

CreateChildItems creates and adds ControlContainingGridViewElement

 

ControlContainingGridViewElement inherits from RadElement

CreateChildItems creates and adds some layout controls AND a GridViewElement

 

public partial class ControlContainingGridView : RadControl {
        public ControlContainingGridView() {
            InitializeComponent();
            this.TextChanged += ControlContainingGridView_TextChanged;
        }

        private void ControlContainingGridView_TextChanged(object sender, EventArgs e) {
            controlContainingGridViewElement.Text = this.Text;
        }

        private ControlContainingGridViewElement controlContainingGridViewElement = null;


        protected override void CreateChildItems(RadElement parent) {
            controlContainingGridViewElement = new ControlContainingGridViewElement();
            this.RootElement.Children.Add(controlContainingGridViewElement);
            base.CreateChildItems(parent);
        }

        public object DataSource {
            get {
                return controlContainingGridViewElement.GridView.Template.DataSource;
            }
            set {
                try {
                    controlContainingGridViewElement.GridView.Template.DataSource = value;
                } catch (Exception ex) {
                    Debug.WriteLine(ex);
                }
            }
        }

        internal void SetupColumns(Action<MasterGridViewTemplate> setupColumns) {
            controlContainingGridViewElement.GridView.Template.AutoGenerateColumns = false;
            setupColumns(controlContainingGridViewElement.GridView.Template);
        }



    }

    public class ControlContainingGridViewElement : RadElement {

        private TextPrimitive textPrimitive = null;
        private RadButtonElement addButton = null;
        private RadButtonElement deleteButton = null;
        private RadGridViewElement gridViewElement = null;

        public RadGridViewElement GridView { get { return gridViewElement; } }

        public bool ShowAddButton { get { return addButton.Visibility == ElementVisibility.Visible; } set { addButton.Visibility = value ? ElementVisibility.Visible : ElementVisibility.Collapsed; } }
        public bool ShowDeleteButton { get { return deleteButton.Visibility == ElementVisibility.Visible; } set { deleteButton.Visibility = value ? ElementVisibility.Visible : ElementVisibility.Collapsed; } }

        public string Text { get { return textPrimitive.Text; } set { textPrimitive.Text = value; } }

        protected override void CreateChildElements() {
            DockLayoutPanel dlp = new DockLayoutPanel();
            dlp.StretchHorizontally = true;
            dlp.StretchHorizontally = true;
            dlp.LastChildFill = true;

            DockLayoutPanel dlpBar = new DockLayoutPanel();
            dlpBar.StretchHorizontally = true;
            DockLayoutPanel.SetDock(dlpBar, Dock.Top);


            var imagePrimitive = new ImagePrimitive();
            DockLayoutPanel.SetDock(imagePrimitive, Dock.Left);

            textPrimitive = new TextPrimitive();
            DockLayoutPanel.SetDock(textPrimitive, Dock.Left);

            var slp = new StackLayoutPanel();
            DockLayoutPanel.SetDock(slp, Dock.Right);

            var addButton = new RadButtonElement {
                Text = "Add",
                MaxSize = new Size() { Height = 20 }
            };
            var deleteButton = new RadButtonElement {
                Text = "Del",
                MaxSize = new Size() { Height = 20 }
            };

            slp.Children.Add(addButton);
            slp.Children.Add(deleteButton);


            dlpBar.Children.Add(slp);
            dlpBar.Children.Add(imagePrimitive);
            dlpBar.Children.Add(textPrimitive);



            gridViewElement = new RadGridViewElement {
                StretchHorizontally = true,
                StretchVertically = true
            };
            gridViewElement.Template.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;
            gridViewElement.Template.AllowAddNewRow = false;
            gridViewElement.Template.AllowDeleteRow = false;
            gridViewElement.Template.AllowDragToGroup = false;
            gridViewElement.ShowGroupPanel = false;
            gridViewElement.ShowGroupPanelScrollbars = false;

            dlp.Children.Add(dlpBar);
            dlp.Children.Add(gridViewElement);



            this.Children.Add(dlp);
            base.CreateChildElements();
        }

    }

 

During Form load, I programmatically add columns and provide a binding source

 

private List<SampleModel> sampleModels = new List<SampleModel>();
        private BindingSource sampleModelsBinding = new BindingSource();

        private void RadForm1_Load(object sender, EventArgs e) {

            sampleModels.Add(new SampleModel() {
                When = DateTime.Parse("1980-04-23"),
                SomeText = "Purple Bananas",
                IsTrue = true
            });
            sampleModels.Add(new SampleModel() {
                When = DateTime.Parse("2002-07-20"),
                SomeText = "Ball & Chain",
                IsTrue = false
            });
            sampleModelsBinding.DataSource = sampleModels;

            controlContainingGridView.SetupColumns((grid) => {
                grid.AddDateTimeColumn(nameof(SampleModel.When), "When");
                grid.AddTextBoxColumn(nameof(SampleModel.SomeText), "Some Text");
                grid.AddCheckBoxColumn(nameof(SampleModel.IsTrue), "Is True");
            });

            controlContainingGridView.DataSource = sampleModelsBinding;

        }

 

Inclusion of the CheckBox column results in the following error:

Exception thrown: 'System.NullReferenceException' in Telerik.WinControls.GridView.dll

System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.WinControls.UI.GridCheckBoxHeaderCellElement.Attach(GridViewColumn data, Object context)
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.InsertElement(Int32 position, IVirtualizedElement`1 element, T data)
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.UpdateElement(Int32 position, T data)
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.MeasureElements()
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
   at Telerik.WinControls.RadElement.Measure(SizeF availableSize)
   at Telerik.WinControls.UI.GridVirtualizedRowElement.MeasureElements(SizeF availableSize, SizeF clientSize, Padding borderThickness)
   at Telerik.WinControls.UI.LightVisualElement.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.UI.GridRowElement.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
   at Telerik.WinControls.RadElement.Measure(SizeF availableSize)
   at Telerik.WinControls.UI.VirtualizedStackContainer`1.MeasureElementCore(RadElement element, SizeF availableSize)
   at Telerik.WinControls.UI.ScrollableRowsContainerElement.MeasureElementCore(RadElement element, SizeF availableSize)
   at Telerik.WinControls.UI.VirtualizedStackContainer`1.MeasureElement(IVirtualizedElement`1 element)
   at Telerik.WinControls.UI.PinnedRowsContainerElement.MeasureElement(IVirtualizedElement`1 element)
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.MeasureElements()
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.UI.ScrollableRowsContainerElement.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
   at Telerik.WinControls.RadElement.Measure(SizeF availableSize)
   at Telerik.WinControls.UI.RowsContainerElement.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
   at Telerik.WinControls.RadElement.Measure(SizeF availableSize)
   at Telerik.WinControls.UI.ScrollViewElement`1.MeasureViewElement(SizeF availableSize)
   at Telerik.WinControls.UI.ScrollViewElement`1.MeasureView(SizeF availableSize)
   at Telerik.WinControls.UI.ScrollViewElement`1.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.UI.GridTableElement.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
   at Telerik.WinControls.RadElement.Measure(SizeF availableSize)
   at Telerik.WinControls.Layouts.DockLayoutPanel.MeasureOverride(SizeF constraint)
   at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
   at Telerik.WinControls.RadElement.Measure(SizeF availableSize)
   at Telerik.WinControls.Layouts.ContextLayoutManager.UpdateLayout()
   at Telerik.WinControls.UI.GridVisibilityHelper.EnsureRowVisible(GridViewRowInfo rowInfo)
   at Telerik.WinControls.UI.GridTableElement.EnsureRowVisible(GridViewRowInfo rowInfo)
   at Telerik.WinControls.UI.GridTableElement.EnsureCellVisible(GridViewRowInfo rowInfo, GridViewColumn column)
   at Telerik.WinControls.UI.GridTableElement.UpdateViewCore(Object sender, DataViewChangedEventArgs args)
   at Telerik.WinControls.UI.GridTableElement.UpdateView(Object sender, DataViewChangedEventArgs args)
   at Telerik.WinControls.UI.GridTableElement.ProcessTemplateEvent(GridViewEvent eventData)
   at Telerik.WinControls.UI.GridTableElement.Telerik.WinControls.UI.IGridViewEventListener.ProcessEvent(GridViewEvent eventData)
   at Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessCollection(GridViewEvent gridEvent, PriorityWeakReferenceList list, GridEventProcessMode processMode)
   at Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessEvent(GridViewEvent gridEvent)
   at Telerik.WinControls.UI.GridViewSynchronizationService.NotifyListeners(GridViewEvent gridEvent)
   at Telerik.WinControls.UI.GridViewSynchronizationService.FlushEvents()
   at Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewEvent gridEvent)
   at Telerik.WinControls.UI.GridViewSynchronizationService.RaiseCurrentChanged(GridViewTemplate template, GridViewRowInfo row, GridViewColumn column, Boolean user)
   at Telerik.WinControls.UI.GridViewTemplate.CollectionView_CurrentChanged(Object sender, EventArgs e)
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at Telerik.WinControls.Data.RadCollectionView`1.OnCurrentChanged(EventArgs args)
   at Telerik.WinControls.Data.RadCollectionView`1.SetCurrentPositionCore(Int32 newPosition, Boolean forceNotify, CurrentChangeReason reason)
   at Telerik.WinControls.Data.RadListSource`1.InitializeCurrentItem()
   at Telerik.WinControls.Data.RadListSource`1.Initialize()
   at Telerik.WinControls.Data.RadListSource`1.Bind(Object dataSource, String dataMember)
   at Telerik.WinControls.Data.RadListSource`1.set_DataSource(Object value)
   at Telerik.WinControls.UI.GridViewTemplate.set_DataSource(Object value)
   at BugReproduction.ControlContainingGridView.set_DataSource(Object value) in ...\BugReproduction\BugReproduction\ControlContainingGridView.cs:line 42

Under Review
Last Updated: 27 Jun 2019 09:40 by ADMIN

Please refer to the attached gif file. You will notice that for the GridViewMaskBoxColumn  with numeric mask the filtering doesn't work. For the other columns each key stroke filters the grid rows.

Workaround: either use a GridViewDecimalColumn or change the default editor for the GridViewMaskBoxColumn :


            this.radGridView1.EditorRequired += radGridView1_EditorRequired; 

        private void radGridView1_EditorRequired(object sender, EditorRequiredEventArgs e)
        {
            if (this.radGridView1.CurrentColumn.HeaderText == "MaskBoxColumn")
            {
                GridSpinEditor spinEditor = new GridSpinEditor();
                RadSpinEditorElement element = spinEditor.EditorElement as RadSpinEditorElement;
                element.ShowUpDownButtons = false;
                e.Editor = spinEditor;
            }
        }

 

 

Under Review
Last Updated: 11 Sep 2018 12:05 by ADMIN
ADMIN
Created by: Telerik Admin
Comments: 5
Category: GridView
Type: Bug Report
1
Hi,

Following to the workaroud (flag IsSearchAsync) provided (https://feedback.telerik.com/Project/154/Feedback/Details/245938-fix-radgridview-having-groups-filters-sort-descriptors-and-search-query-in-t), we discovered two issues :

1) the behavior of the grid is changed while using IsSearchAsync as true or false (see 2018-08-01_1849_DragDrop_behavior_with_IsSearchAsync.swf video attached). When set to true, the line found by the searchbox is automatically reselected. When the flag is set to false, it's not the case.

2) while playing with drag&drop, after some time the grid became unstable (see 2018-08-01_1847_-_dragdrop_issue_with_IsAsyncSearch.swf video attached). You can see that at the beginning, the D&D works fine. At 0:20 I can't select any line, and when I try to D&D, it drops always the same customer. At 0:40 you can see that even the SearchBox is broken and the progressbar is looping forever
Under Review
Last Updated: 11 Sep 2018 12:01 by ADMIN
Use attached to reproduce.

Workaround:
Set the TableHeaderHeight again after loading the layout.