Workaround: create custom GanttViewTimelineItemElement with special layout arranging the elements in depending on their parent`s final size. The attached project features a possible implementation.

To reproduce: click (mouse down) on a task but then release the mouse button off the task. It then stays selected even when I click on other tasks. You can repeat this over and over and end up with every task as "selected" as shown in the video.

Workaround:

 AddHandler Me.RadGanttView1.GraphicalViewItemFormatting, AddressOf GraphicalViewItemFormatting

Private Sub GraphicalViewItemFormatting(sender As Object, e As GanttViewGraphicalViewItemFormattingEventArgs)
    Dim taskItem As GanttViewTaskItemElement = TryCast(e.ItemElement, GanttViewTaskItemElement)
    If taskItem IsNot Nothing AndAlso taskItem.TaskElement.VisualState.Contains(".MouseDown") AndAlso Not taskItem.Selected Then
        taskItem.TaskElement.IsMouseDown = False
    End If
End Sub

Add new timeline view which shows Time/Hours

This event should be fired when a task is modified either by the graphical view or by the columns on the left side. In the arguments you should have access to the changed property.

To reproduce:
1) Open the Demo application >> Settings example.
2) Select a task and activate the editor for it.
3) Delete the task by clicking the button above.

It may be necessary to repeat the steps several times. The error is not reproduced immediately. 

To reproduce:
- Set the range to lest than one day.
- Set the TimelineRange to DayHalfHours

Workaround: 
Make sure that the range is at least one day. 

To reproduce: run the sample project and try to move a task.

Workaround:

 Timer timer = new Timer();

        private void DragDropService_Stopped(object sender, EventArgs e)
        {
            timer = new Timer();
            timer.Interval = 300;
            timer.Tick += timer_Tick;
            
        }

        private void timer_Tick(object sender, EventArgs e)
        {
            timer.Stop();
            data.Tables["Tasks"].Clear();
        }

Workaround 2:

        private void radGanttView1_ItemElementCreating(object sender, Telerik.WinControls.UI.GanttViewItemElementCreatingEventArgs e)
        {
            if (e.Item.Items.Count == 0 && e.ViewElement is GanttViewGraphicalViewElement)
            {
                e.ItemElement = new MyGanttViewTaskItemElement(e.ViewElement as GanttViewGraphicalViewElement); 
            }
        }

        public class MyGanttViewTaskItemElement : GanttViewTaskItemElement
        {
            public MyGanttViewTaskItemElement(GanttViewGraphicalViewElement ganttViewBaseViewElement) : base(ganttViewBaseViewElement)
            {
            }
            
            protected override Type ThemeEffectiveType
            {
                get
                {
                    return typeof(GanttViewTaskItemElement);
                }
            }

            public override void Detach()
            {
                var obj = this.Data;
                this.Data.SuspendPropertyNotifications();
                base.Detach();
                obj.ResumePropertyNotifications(); 
            }

            public override void Synchronize()
            {
                DataSet ds = this.Data.GanttViewElement.DataSource as DataSet;
                if (ds != null && this.Data != null)
                {
                    DataRowView rowView = this.Data.DataBoundItem as DataRowView;
                    if (rowView != null && !RowExists(rowView.Row))//!ds.Tables[0].Rows.Contains(rowView.Row))
                    {
                        return;
                    }
                }
                base.Synchronize();
            }

            private bool RowExists(DataRow dataRow)
            {
                DataSet ds = this.Data.GanttViewElement.DataSource as DataSet;
                bool res = false;
                foreach (DataRow r in ds.Tables[0].Rows)
                {
                    if (r.Equals(dataRow))
                    {
                        return true;
                    }
                }
                return res;
            }
        }

When you edit a link, e.g. change its end item, there is no appropriate event to handle this situation. The Links.CollectionChanged event is not fired. It would be nice to have a LinkChanged event which will be fired when a link is modified similar to the ItemChanged event for the tasks.

Workaround:
            foreach (GanttViewLinkDataItem link in this.radGanttView1.Links)
            {
                link.PropertyChanged += link_PropertyChanged;
            }

        private void link_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (e.PropertyName == "EndItem")
            {
            }
            
        }

Hey,

We have a problem with the GanttViewTimeLineContainer as you see in the screeshot  : gantt_print2.png

When we are in TimeLineRange = TimeRange.Year and we print the gantt, we have a problem with the appearence of GanttViewTimeLineContainer, we can see the first line with the year (it's ok) but after, the second line we can see a reperition of all month : jfmamjjasond jfmamjjasond jfmamjjasond jfmamjjasond etc etc etc

Can we change the appearence ? Do you have an explanation for this visualization ? 

Thank you,

Regards,

Valériane E.

If one applies a TypeConverter with standard values to a property, this type converter is not used to convert these standard values to and from string when they are displayed in a drop down list editor.

To reproduce:

Open QSF, go to GanttView, open the Settings example, go to the very last task and change the view mode to month. You will notice that the positions of the tasks are not being updated

To reproduce:
Add Tasks which appear far after the start of the timeline. You will notice that some of them are not displayed at the right position.

To reproduce: add a RadGanttView and populate it with data. Use the  GraphicalViewItemFormatting event in order to change the e.ItemElement.TaskElement.Text. However, the changes are not applied.

Workaround:
 private void radGanttView1_GraphicalViewItemFormatting(object sender, GanttViewGraphicalViewItemFormattingEventArgs e)
 {
     e.ItemElement.Tag = "Custom text";
 }

 public class CustomRadGanttView : RadGanttView
 {
     protected override RadGanttViewElement CreateGanttViewElement()
     {
         return new CustomRadGanttViewElement();
     }

     public override string ThemeClassName  
     { 
         get 
         { 
             return typeof(RadGanttView).FullName;  
         }
     }
 }

 public class CustomRadGanttViewElement : RadGanttViewElement
 {
     public CustomRadGanttViewElement()
     {
     }

     protected override Type ThemeEffectiveType     
     { 
         get    
         { 
             return typeof(RadGanttViewElement);     
         }
     }
     
     protected override GanttViewGraphicalViewElement CreateGraphicalViewElement(RadGanttViewElement ganttView)
     {
         return new CustomGanttViewGraphicalViewElement(ganttView);
     }
 }

 public class CustomGanttViewGraphicalViewElement : GanttViewGraphicalViewElement
 {
     public CustomGanttViewGraphicalViewElement(RadGanttViewElement ganttView) : base(ganttView)
     {
     }

     protected override Type ThemeEffectiveType     
     { 
         get    
         { 
             return typeof(GanttViewGraphicalViewElement);     
         }
     }
     
     protected override IVirtualizedElementProvider<GanttViewDataItem> CreateElementProvider()
     {
         return new CustomGanttViewVirtualizedElementProvider(this);
     }
 }

 public class CustomGanttViewVirtualizedElementProvider : GanttViewVirtualizedElementProvider
 {
     public CustomGanttViewVirtualizedElementProvider(GanttViewBaseViewElement owner) : base(owner)
     {
     }

     public override IVirtualizedElement<GanttViewDataItem> CreateElement(GanttViewDataItem data, object context)
     {
         IVirtualizedElement<GanttViewDataItem> taskElement = base.CreateElement(data, context) ;
         if (taskElement is GanttViewTaskItemElement)
         {
             FieldInfo fi = typeof(GanttViewVirtualizedElementProvider).GetField("owner", BindingFlags.NonPublic | BindingFlags.Instance);
             GanttViewBaseViewElement owner = fi.GetValue(this) as GanttViewBaseViewElement ;
               
             return new CustomGanttViewTaskItemElement(owner as GanttViewGraphicalViewElement);
         }

         return taskElement;
     }
 }

 public class CustomGanttViewTaskItemElement:GanttViewTaskItemElement
 {
     public CustomGanttViewTaskItemElement(GanttViewGraphicalViewElement owner) : base(owner)
     {
     }

     public override void Synchronize()
     {
         base.Synchronize();
         
         if (this.Tag != null)
         {
             this.TaskElement.Text = this.Tag.ToString();
         }
     }
 }

To reproduce:
public RadForm1()
{
    InitializeComponent();
    DataTable tasks = new DataTable("Tasks");
    tasks.Columns.Add("Id", typeof(int));
    tasks.Columns.Add("ParentId", typeof(int));
    tasks.Columns.Add("Title", typeof(string));
    tasks.Columns.Add("Start", typeof(DateTime));
    tasks.Columns.Add("End", typeof(DateTime));
    tasks.Columns.Add("Progress", typeof(decimal));

    DataTable links = new DataTable("Links");
    links.Columns.Add("StartId", typeof(int));
    links.Columns.Add("EndId", typeof(int));
    links.Columns.Add("LinkType", typeof(int));

    tasks.Rows.Add(1, 0, "Summary task title", new DateTime(2010, 10, 8), new DateTime(2010, 10, 18), 30m);
    tasks.Rows.Add(2, 1, "First child task title", new DateTime(2010, 10, 10), new DateTime(2010, 10, 12), 10);
    tasks.Rows.Add(3, 1, "Second child task title", new DateTime(2010, 10, 12), new DateTime(2010, 10, 15), 20m);
    tasks.Rows.Add(4, 1, "Milestone", new DateTime(2010, 10, 15), new DateTime(2010, 10, 15), 0m);

    links.Rows.Add(2, 3, 1);
    links.Rows.Add(3, 4, 1);

    DataSet data = new DataSet();
    data.Tables.Add(tasks.Copy());
    data.Tables.Add(links);

    this.radGridView1.DataSource = tasks;
    radGridView1.BestFitColumns();

    this.radGanttView1.CreateDataItem += radGanttView1_CreateDataItem;
    this.radGanttView1.AllowSummaryEditing = true;
    this.radGanttView1.GanttViewElement.TaskDataMember = "Tasks";
    this.radGanttView1.GanttViewElement.ChildMember = "Id";
    this.radGanttView1.GanttViewElement.ParentMember = "ParentId";
    this.radGanttView1.GanttViewElement.TitleMember = "Title";
    this.radGanttView1.GanttViewElement.StartMember = "Start";
    this.radGanttView1.GanttViewElement.EndMember = "End";
    this.radGanttView1.GanttViewElement.ProgressMember = "Progress";
    this.radGanttView1.GanttViewElement.LinkDataMember = "Links";
    this.radGanttView1.GanttViewElement.LinkStartMember = "StartId";
    this.radGanttView1.GanttViewElement.LinkEndMember = "EndId";
    this.radGanttView1.GanttViewElement.LinkTypeMember = "LinkType";

    this.radGanttView1.GanttViewElement.DataSource = data;

    this.radGanttView1.Columns.Add("Start");
    this.radGanttView1.Columns.Add("End");
    this.radGanttView1.Columns.Add("Progress");

    this.radGanttView1.GanttViewElement.GraphicalViewElement.TimelineStart = new DateTime(2010, 10, 7);
    this.radGanttView1.GanttViewElement.GraphicalViewElement.TimelineEnd = new DateTime(2010, 12, 10);
}
You will notice that the start and end of the summary task are changed in the gantt view.

Workaround:
void radGanttView1_CreateDataItem(object sender, CreateGanttDataItemEventArgs e)
{
    e.Item = new MyGanttViewDataItem();
}

public class MyGanttViewDataItem : GanttViewDataItem
{
    protected override void OnChildAdded(GanttViewDataItem child)
    {
        if (this.Parent != null && !this.GanttViewElement.AllowSummaryEditing)
        {
            base.OnChildAdded(child);
        }
    }

    protected override void OnChildRemoved(GanttViewDataItem child)
    {
        if (this.Parent != null && !this.GanttViewElement.AllowSummaryEditing)
        {
            base.OnChildRemoved(child);
        }
    }
}

Dim data As New DataSet()
Dim tasks As New DataTable("Tasks")
Dim links As New DataTable("Links")
Sub New()
    InitializeComponent()

    tasks.Columns.Add("Id", GetType(Integer))
    tasks.Columns.Add("ParentId", GetType(Integer))
    tasks.Columns.Add("Title", GetType(String))
    tasks.Columns.Add("Start", GetType(DateTime))
    tasks.Columns.Add("End", GetType(DateTime))
    tasks.Columns.Add("Progress", GetType(Decimal))

    links.Columns.Add("StartId", GetType(Integer))
    links.Columns.Add("EndId", GetType(Integer))
    links.Columns.Add("LinkType", GetType(Integer))

    data.Tables.Add(tasks)
    data.Tables.Add(links)
    tasks.Rows.Add(1, 0, "1. Summary task title", New DateTime(2010, 10, 10), New DateTime(2010, 10, 15), 30D)
    tasks.Rows.Add(2, 1, "1.1 Task", New DateTime(2010, 10, 10), New DateTime(2010, 10, 12), 10)
    tasks.Rows.Add(3, 1, "1.2 Task", New DateTime(2010, 10, 12), New DateTime(2010, 10, 15), 20D)
    tasks.Rows.Add(4, 1, "1.3 Task", New DateTime(2010, 10, 10), New DateTime(2010, 10, 11), 20D)
    tasks.Rows.Add(5, 1, "Milestone", New DateTime(2010, 10, 15), New DateTime(2010, 10, 15), 0D)
    tasks.Rows.Add(6, 0, "2. Summary task title", New DateTime(2010, 10, 10), New DateTime(2010, 10, 13), 30D)
    tasks.Rows.Add(7, 6, "2.1 Task", New DateTime(2010, 10, 10), New DateTime(2010, 10, 11), 10)
    links.Rows.Add(2, 3, 1)
    links.Rows.Add(3, 5, 1)

    Bind()
    Me.RadGanttView1.Columns.Add("Start")
    Me.RadGanttView1.Columns.Add("End")
    Me.RadGanttView1.Columns.Add("Id")
    Me.RadGanttView1.Columns.Add("ParentId")

    Me.RadGanttView1.GanttViewElement.GraphicalViewElement.TimelineStart = New DateTime(2010, 10, 9)
End Sub

Private Sub Bind()
    Me.RadGanttView1.GanttViewElement.DataSource = Nothing
    Me.RadGanttView1.GanttViewElement.TaskDataMember = "Tasks"
    Me.RadGanttView1.GanttViewElement.ChildMember = "Id"
    Me.RadGanttView1.GanttViewElement.ParentMember = "ParentId"
    Me.RadGanttView1.GanttViewElement.TitleMember = "Title"
    Me.RadGanttView1.GanttViewElement.StartMember = "Start"
    Me.RadGanttView1.GanttViewElement.EndMember = "End"
    Me.RadGanttView1.GanttViewElement.ProgressMember = "Progress"
    Me.RadGanttView1.GanttViewElement.LinkDataMember = "Links"
    Me.RadGanttView1.GanttViewElement.LinkStartMember = "StartId"
    Me.RadGanttView1.GanttViewElement.LinkEndMember = "EndId"
    Me.RadGanttView1.GanttViewElement.LinkTypeMember = "LinkType"
    Me.RadGanttView1.GanttViewElement.DataSource = data
End Sub

Private Sub RadButtonClick(sender As Object, e As EventArgs) Handles RadButton2.Click
    tasks(3)("ParentId") = 6
    Bind()
End Sub

Workaround: rebind the ganttview after changing the parent.

Workaround: handle the RadGanttView.GraphicalViewItemFormatting event:

    Private Sub GraphicalViewItemFormatting(sender As Object, e As GanttViewGraphicalViewItemFormattingEventArgs)
        Dim taskItem As GanttViewTaskItemElement = TryCast(e.ItemElement, GanttViewTaskItemElement)
        If taskItem IsNot Nothing Then
            taskItem.LeftLinkHandleElement.Opacity = 0
            taskItem.RightLinkHandleElement.Opacity = 0
        End If 
    End Sub

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

            this.radGanttView1.GanttViewElement.GraphicalViewElement.TimelineStart = new DateTime(2010, 10, 9);
            this.radGanttView1.GanttViewElement.GraphicalViewElement.TimelineEnd = new DateTime(2010, 12, 10);

            //setup data items
            GanttViewDataItem item1 = new GanttViewDataItem();
            item1.Start = new DateTime(2010, 10, 10);
            item1.End = new DateTime(2010, 10, 15);
            item1.Progress = 30m;
            item1.Title = "Summary task.1. title";

            GanttViewDataItem subitem11 = new GanttViewDataItem();
            subitem11.Start = new DateTime(2010, 10, 10);
            subitem11.End = new DateTime(2010, 10, 12);
            subitem11.Progress = 10m;
            subitem11.Title = "Sub-task.1.1 title";

            GanttViewDataItem subitem12 = new GanttViewDataItem();
            subitem12.Start = new DateTime(2010, 10, 12);
            subitem12.End = new DateTime(2010, 10, 15);
            subitem12.Progress = 20m;
            subitem12.Title = "Sub-task.1.2 title";

            //add subitems
            item1.Items.Add(subitem11);
            item1.Items.Add(subitem12);

            this.radGanttView1.Items.Add(item1);

            GanttViewDataItem item2 = new GanttViewDataItem();
            item2.Start = new DateTime(2010, 10, 12);
            item2.End = new DateTime(2010, 10, 18);
            item2.Progress = 40m;
            item2.Title = "Summary task.2. title";

            GanttViewDataItem subitem21 = new GanttViewDataItem();
            subitem21.Start = new DateTime(2010, 10, 12);
            subitem21.End = new DateTime(2010, 10, 13);
            subitem21.Progress = 10m;
            subitem21.Title = "Sub-task.2.1 title";

            GanttViewDataItem subitem22 = new GanttViewDataItem();
            subitem22.Start = new DateTime(2010, 10, 13);
            subitem22.End = new DateTime(2010, 10, 18);
            subitem22.Progress = 30m;
            subitem22.Title = "Sub-task.2.2 title";

            GanttViewDataItem subitem23 = new GanttViewDataItem();
            subitem23.Start = new DateTime(2010, 10, 18);
            subitem23.End = new DateTime(2010, 10, 18);
            subitem23.Title = "Sub-task.2.3 title";

            //add subitems
            item2.Items.Add(subitem21);
            item2.Items.Add(subitem22);
            item2.Items.Add(subitem23);

            this.radGanttView1.Items.Add(item2);

            //add links between items
            GanttViewLinkDataItem link1 = new GanttViewLinkDataItem();
            link1.StartItem = subitem11;
            link1.EndItem = subitem12;
            link1.LinkType = TasksLinkType.FinishToStart;
            this.radGanttView1.Links.Add(link1);

            GanttViewLinkDataItem link2 = new GanttViewLinkDataItem();
            link2.StartItem = subitem21;
            link2.EndItem = subitem22;
            link2.LinkType = TasksLinkType.StartToStart;
            this.radGanttView1.Links.Add(link2);

            GanttViewLinkDataItem link3 = new GanttViewLinkDataItem();
            link3.StartItem = subitem22;
            link3.EndItem = subitem23;
            link3.LinkType = TasksLinkType.FinishToStart;
            this.radGanttView1.Links.Add(link3);

            GanttViewTextViewColumn titleColumn = new GanttViewTextViewColumn("Title");
            GanttViewTextViewColumn startColumn = new GanttViewTextViewColumn("Start");
            GanttViewTextViewColumn endColumn = new GanttViewTextViewColumn("End");

            this.radGanttView1.GanttViewElement.Columns.Add(titleColumn);
            this.radGanttView1.GanttViewElement.Columns.Add(startColumn);
            this.radGanttView1.GanttViewElement.Columns.Add(endColumn);

            this.radGanttView1.GanttViewElement.GraphicalViewElement.TimelineStart = new DateTime(2010, 10, 13);
        }

        private void radButton1_Click(object sender, EventArgs e)
        {
            RadPrintDocument doc = new RadPrintDocument();
            doc.Landscape = true;
            RadPrintPreviewDialog dialog = new RadPrintPreviewDialog();
            doc.AssociatedObject = this.radGanttView1;
            dialog.Document = doc;
            dialog.ShowDialog();
        }
    }

Workaround: create a custom RadGanttView
public class MyRadGanttView : RadGanttView
{
    public override string ThemeClassName
    {
        get
        {
            return typeof(RadGanttView).FullName;
        }
    }

    protected override PointF[] GetElementShape(GanttViewPrintElementContext context, RectangleF rect)
    {
        if (shouldPaintStartCap)
        {
            return base.GetElementShape(context, rect);
        }

        switch (context)
        {
            case GanttViewPrintElementContext.SummaryTaskElement:
                PointF[] summaryPoints = new PointF[5];
                summaryPoints[0] = rect.Location;
                summaryPoints[1] = new PointF(rect.X, rect.Y + rect.Height / 4f);
                summaryPoints[2] = new PointF(rect.Right - 3, rect.Y + rect.Height / 4f);
                summaryPoints[3] = new PointF(rect.Right, rect.Y + rect.Height / 2f);
                summaryPoints[4] = new PointF(rect.Right, rect.Y);
                
                return summaryPoints;
            case GanttViewPrintElementContext.MilestoneElement:
                PointF[] milestonePoints = new PointF[4];
                milestonePoints[0] = new PointF(rect.X, rect.Y);
                milestonePoints[1] = new PointF(rect.X + rect.Height / 2f, rect.Y + rect.Height / 2f);
                milestonePoints[2] = new PointF(rect.X, rect.Y + rect.Height);
                milestonePoints[3] = new PointF(rect.X - rect.Height / 2f, rect.Y + rect.Height / 2f);

                return milestonePoints;
            default:
                return null;
        }
    }

    private bool shouldPaintStartCap;
    protected override RectangleF GetPrintRectangle(GanttViewDataItem item, int index)
    {
        if (index < 0)
        {
            return RectangleF.Empty;
        }
        
        float x = (float)((item.Start - this.GanttViewElement.GraphicalViewElement.TimelineBehavior.AdjustedTimelineStart).TotalSeconds / this.GanttViewElement.GraphicalViewElement.OnePixelTime.TotalSeconds);
        this.shouldPaintStartCap = x > 0 ? true : false;
        x = Math.Max(x, 0);

        float y = index * (this.GanttViewElement.ItemHeight + this.GanttViewElement.ItemSpacing) + this.GanttViewElement.HeaderHeight;
        float width = (float)((item.End - item.Start).TotalSeconds / (float)this.GanttViewElement.GraphicalViewElement.OnePixelTime.TotalSeconds);

        return new RectangleF(x, y, width, (this.GanttViewElement.ItemHeight + this.GanttViewElement.ItemSpacing));
    }
}

See attached video to reproduce.

Workaround:

class MyGantt : RadGanttView
{

    protected override RadGanttViewElement CreateGanttViewElement()
    {
        return new MyGanttElement();
    }
}
class MyGanttElement : RadGanttViewElement
{
    
    protected override void InitializeFields()
    {
        base.InitializeFields();
        ThemeRole = "RadGanttViewElement";
    }

    protected override bool EndEditCore(bool commitChanges)
    {
        if (this.ActiveEditor.Value == null)
        {
            GanttViewDataItem item = this.SelectedItem as GanttViewDataItem;
            this.ActiveEditor.Value = item[CurrentColumn];
           
        }
        return base.EndEditCore(commitChanges);
    }
}

Workaround: In the case of DateTime columns one can handle the PrintElementFormating event and change text of the print elements with the required format string
private void RadGanttView1_PrintElementFormatting(object sender, Telerik.WinControls.UI.GanttViewPrintElementFormattingEventArgs e)
{
    if (e.PrintContext == GanttViewPrintElementContext.DataCell)
    {
        DateTime date;
        if (e.PrintElement.DrawText && DateTime.TryParse(e.PrintElement.Text, out date))
        {
            e.PrintElement.Text = string.Format("{0:D}", date);
        }
    }
}