Completed
Last Updated: 22 Aug 2019 13:22 by ADMIN
ADMIN
Dess | Tech Support Engineer, Sr.
Created on: 12 Dec 2017 07:35
Category: GridView
Type: Bug Report
1
FIX. RadGridView - NullReferenceException when GridViewCheckBoxColumn.EnableHeaderCheckBox is true for the child template and the master level is self-reference
To reproduce: run the attached project and toggle the checkbox in the header cell of the child template. 

Workaround: use a custom GridCheckBoxHeaderCellElement


    public partial class RadForm1 : Telerik.WinControls.UI.RadForm
    {
        public RadForm1()
        {
            InitializeComponent();

            this.radGridView1.CreateCell += radGridView1_CreateCell;

            DataTable dt = new DataTable();
            dt.Columns.Add("CategoryId", typeof(int));
            dt.Columns.Add("CategoryName", typeof(string));
            dt.Columns.Add("ParentCategoryId", typeof(int));

            dt.Rows.Add(1, "Category1", 0);
            dt.Rows.Add(2, "Category2", 0);
            dt.Rows.Add(3, "Category3", 0);

            Random rand = new Random();
            for (int i = 4; i < 20; i++)
            {
                dt.Rows.Add(i, "Category" + i, rand.Next(1, 4));
            }
            this.radGridView1.Relations.AddSelfReference(this.radGridView1.MasterTemplate, "CategoryId", "ParentCategoryId");
            this.radGridView1.DataSource = dt;
            this.radGridView1.AutoSizeColumnsMode = Telerik.WinControls.UI.GridViewAutoSizeColumnsMode.Fill;

            GridViewTemplate childTemplate = CreateChildTemplate();
            GridViewRelation relation = new GridViewRelation(
                this.radGridView1.MasterTemplate,
                childTemplate);
            relation.ChildColumnNames.Add("CategoryId");
            relation.ParentColumnNames.Add("CategoryId");
            this.radGridView1.Relations.Add(relation);
        }

        private void radGridView1_CreateCell(object sender, GridViewCreateCellEventArgs e)
        {
            if (e.CellType == typeof(GridCheckBoxHeaderCellElement))
            {
                e.CellElement = new CustomGridCheckBoxHeaderCellElement(e.Column, e.Row);
            }
        }

        private GridViewTemplate CreateChildTemplate()
        {
            GridViewTemplate childTemplate = new GridViewTemplate();
            childTemplate.AutoGenerateColumns = false;
            this.radGridView1.Templates.Add(childTemplate);

            GridViewDecimalColumn decColumn = new GridViewDecimalColumn
            {
                Name = "CategoryId",
                HeaderText = "CategoryId Id",
                FieldName = "CategoryId",
                IsVisible = false,
                MinWidth = 100
            };
            childTemplate.Columns.Add(decColumn);

            GridViewTextBoxColumn tbxColumn = new GridViewTextBoxColumn
            {
                Name = "RightName",
                HeaderText = "Right Name",
                FieldName = "RGT_NAME",
                ReadOnly = true,
                MinWidth = 100
            };
            childTemplate.Columns.Add(tbxColumn);

            GridViewCheckBoxColumn chkxColumn = new GridViewCheckBoxColumn
            {
                Name = "Checkbox",
                EnableHeaderCheckBox = true,
                FieldName = "HasAccess",
            };
            childTemplate.Columns.Add(chkxColumn);
            childTemplate.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;
            return childTemplate;
        }

        public class CustomGridCheckBoxHeaderCellElement : GridCheckBoxHeaderCellElement
        {
            public CustomGridCheckBoxHeaderCellElement(GridViewColumn column, GridRowElement row) : base(column, row)
            {
            }

            public bool SuspendProcessingToggleStateChanged
            {
                get
                {
                    FieldInfo fi = typeof(GridCheckBoxHeaderCellElement).GetField("suspendProcessingToggleStateChanged", BindingFlags.NonPublic | BindingFlags.Instance);
                    return (bool)fi.GetValue(this);
                }
                set
                {
                    FieldInfo fi = typeof(GridCheckBoxHeaderCellElement).GetField("suspendProcessingToggleStateChanged", BindingFlags.NonPublic | BindingFlags.Instance);
                    fi.SetValue(this, value);
                }
            }

            public bool ShouldCheckDataRows
            {
                get
                {
                    FieldInfo fi = typeof(GridCheckBoxHeaderCellElement).GetField("shouldCheckDataRows", BindingFlags.NonPublic | BindingFlags.Instance);
                    return (bool)fi.GetValue(this);
                }
                set
                {
                    FieldInfo fi = typeof(GridCheckBoxHeaderCellElement).GetField("shouldCheckDataRows", BindingFlags.NonPublic | BindingFlags.Instance);
                    fi.SetValue(this, value);
                }
            }

            protected override void checkbox_ToggleStateChanged(object sender, StateChangedEventArgs args)
            {
                if (SuspendProcessingToggleStateChanged)
                {
                    return;
                }

                if (this.ViewTemplate != null && !this.ViewTemplate.IsSelfReference && !this.MasterTemplate.IsSelfReference)
                {
                    this.MasterTemplate.BeginUpdate();
                }
                else
                {
                    this.TableElement.BeginUpdate();
                }

                object valueState = DBNull.Value;

                if (args.ToggleState == ToggleState.On)
                {
                    valueState = true;
                }
                else if (args.ToggleState == ToggleState.Off)
                {
                    valueState = false;
                }
                else if (args.ToggleState == ToggleState.Indeterminate)
                {
                    valueState = null;
                }

                RaiseToggleStateEvent();

                if (!ShouldCheckDataRows)
                {
                    if (this.ViewTemplate != null && !this.ViewTemplate.IsSelfReference && !this.MasterTemplate.IsSelfReference)
                    {
                        this.MasterTemplate.EndUpdate(true, new DataViewChangedEventArgs(ViewChangedAction.DataChanged));
                    }

                    return;
                }

                this.GridViewElement.EditorManager.EndEdit();

                this.TableElement.BeginUpdate();
                this.MasterTemplate.MasterViewInfo.TableSearchRow.SuspendSearch();
                List<GridViewRowInfo> list = GetRowsToIterateOver();
                foreach (GridViewRowInfo rowInfo in list)
                {
                    GridViewGroupRowInfo groupRow = rowInfo as GridViewGroupRowInfo;

                    if (groupRow != null)
                    {
                        this.CheckAllCheckBoxInChildRows(groupRow, valueState);
                    }
                    else
                    {
                        rowInfo.Cells[this.ColumnIndex].Value = valueState;
                    }
                }
                this.MasterTemplate.MasterViewInfo.TableSearchRow.ResumeSearch();
                this.TableElement.EndUpdate(false);

                if (this.ViewTemplate != null && !this.ViewTemplate.IsSelfReference && !this.MasterTemplate.IsSelfReference)
                {
                    this.MasterTemplate.EndUpdate(true, new DataViewChangedEventArgs(ViewChangedAction.DataChanged));
                }
                else
                {
                    this.TableElement.EndUpdate(false);
                }

                this.TableElement.Update(GridUINotifyAction.DataChanged);
            }

            private void CheckAllCheckBoxInChildRows(GridViewGroupRowInfo row, object state)
            {
                List<GridViewRowInfo> list = new List<GridViewRowInfo>();

                foreach (GridViewRowInfo rowInfo in row.ChildRows)
                {
                    list.Add(rowInfo);
                }

                foreach (GridViewRowInfo rowInfo in list)
                {
                    GridViewGroupRowInfo groupInfo = rowInfo as GridViewGroupRowInfo;
                    if (groupInfo != null)
                    {
                        this.CheckAllCheckBoxInChildRows(groupInfo, state);
                    }
                    else
                    {
                        rowInfo.Cells[this.ColumnIndex].Value = state;
                    }
                }
            }

            private List<GridViewRowInfo> GetRowsToIterateOver()
            {
                if (this.ViewTemplate != null && this.ViewTemplate.IsSelfReference)
                {
                    PrintGridTraverser traverser = new PrintGridTraverser(this.ViewInfo);
                    List<GridViewRowInfo> result = new List<GridViewRowInfo>();

                    while (traverser.MoveNext())
                    {
                        if (traverser.Current is GridViewDataRowInfo)
                        {
                            result.Add(traverser.Current);
                        }
                    }

                    return result;
                }

                return new List<GridViewRowInfo>(this.ViewInfo.Rows);
            }
        }
    }
2 comments
ADMIN
Dess | Tech Support Engineer, Sr.
Posted on: 22 Aug 2019 13:22
Hello, Ariel,  

The fix was introduced in R2 2018 SP1 (version 2018.2.621). Please refer to the release notes for a full list with all addressed issues: https://www.telerik.com/support/whats-new/winforms/release-history/ui-for-winforms-r2-2018-sp1-(version-2018-2-619)

However, if you are still experiencing any undesired behavior, I would kindly ask you to submit a support ticket from your account. Thus, you can provide detailed information about the precise case. A sample project demonstrating the problem would be also greatly appreciated. Then, we can further investigate your scenario and determine whether it is an issue in RadGridView or not. Thank you in advance for your cooperation.

I am looking forward to your reply.

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik
Get quickly onboarded and successful with your Telerik and/or Kendo UI products with the Virtual Classroom free technical training, available to all active customers. Learn More.
Ariel
Posted on: 21 Aug 2019 15:30
I'm getting an error that maybe related to this. Was this addressed in any of the later releases?