The exception is thrown for the RotationAngle property.

The issue can be observed also in the opposite direction - the diagram is serialized on a machine with some culture (for example Portugal Porguese - pt-PT) and then restored on a machine with an English culture.

The issue reproduces only when saving and loading between cultures which numeric separators are different. For example, with Bulgarian culture, the number 4.5 is represented as 4,5 (with a comma). With English culture the number will be represented as 4.5 (with a period).

To work this around, create a custom RadDiagramShape and override its Deserialize() method. Then parse the RotationAngle manually, and set it to the RotationAngle property of the shape. After this, set the RotationAngle of the SerializationInfo to null, in order to prevent the default restoring of the property.

To reproduce this use the following code snippet:

Steps to reproduce:

1. Start a new connection from Shape 1, by dragging one of its connectors.
2. Drag the connection over Shape 2. 

Expected: The connector closest to the mouse should get highlighted and when you drop the connection it should get attached to the shape.
Actual: The closest connector is not highlighted. Also, when you drop the connection over the target shape it doesn't get attached.

When executing the DiagramCommands.Nudge command with a provided number as a parameter, the movement of the selected shape is incorrect. 

The undo and redo actions don't work for the "Move Items" event. This means that nothing will happen when you select a Bezier connection (ConnectionType=Bezier) and drag/drop it to a new position, then press Ctrl+Z.

RadDiagramShape has NULL content but has DataContext and ContentTemplate.

In the ContentTemplate there are UIElements defined. Their automation peers are not added in the automation tree.

This can be observed in UIVerify tools.

When you select the Size tab and than select another shape where the Size should not be available, its content is shown whether is enabled or not. The SettingsPane should fallback to an enabled tab when one is disabled.

To work this around you can create a custom RadTabControl and implement custom fallback selection logic there. Then replace the RadTabConrol from the ControlTemplate of the SettingsPaneView with the custom tab control. Check the attached project.

RadDiagram with virtualization turned off.

Randomly positioned 5000 shapes are added in Diagram.

For the test, Shapes are with simplified template consisting pretty much of a single Border and nothing else.

On maximized WPF window, Diagram Load for about 3-3.5 seconds.

On normal WPF window, DIagram loads for about 15 seconds.

As a workaround, you can create a custom class which derives from RadDiagramConnector and override the Serialize() method.

public class CustomConnector : RadDiagramConnector
    {
        static CustomConnector()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomConnector), new FrameworkPropertyMetadata(typeof(CustomConnector)));
        }
    
    public override SerializationInfo Serialize()
        {
            var info = new Telerik.Windows.Diagrams.Core.SerializationInfo(this.GetType());

            if (this.Name != null) info[Telerik.Windows.Diagrams.Core.SerializationConstants.ConnectorName] = this.Name;

            info[Telerik.Windows.Diagrams.Core.SerializationConstants.Offset] = this.Offset.ToInvariant();

            if (Telerik.Windows.Controls.DependencyObjectExtensions.IsLocalValueSet(this, RadDiagramConnector.WidthProperty)) info[Telerik.Windows.Diagrams.Core.SerializationConstants.Width] = this.Width.ToInvariant();
            if (Telerik.Windows.Controls.DependencyObjectExtensions.IsLocalValueSet(this, RadDiagramConnector.HeightProperty)) info[Telerik.Windows.Diagrams.Core.SerializationConstants.Height] = this.Height.ToInvariant();
            this.SerializePrimitives(info);

            return info;
        }
    }
}

This is reproducible only if you set the RotationOrigin property to a value different than (0.5,0.5). Also, the rotation angle is wrong only on the first call of the Rotate() method of the service. 

To work this around you can create a custom RotationService and override its CalculateRotationAngle() method where you can calculate custom angle. 

http://docs.telerik.com/devtools/wpf/controls/raddiagram/features/services

https://github.com/telerik/xaml-sdk/tree/master/Diagram/CustomServices

Use TextTool to create shape with no text but with background.

Pressing enter will close the tool. But the shape remains visible, but you cannot neither select it nor delete it with mouse / keyboard.
By design this shape should be removed both from the Shapes collection and from the diagram surface.

As a workaround you can try deleting this shape manually by overriding the Diagram's CommandExecuted event :

 private void diagram_CommandExecuted(object sender, CommandRoutedEventArgs e)
        {
            if (e.Command.Name == "Edit Item")
            {
                foreach (RadDiagramTextShape textShape in this.diagram.ChildrenOfType<RadDiagramTextShape>())
                {
                    if (!this.diagram.Shapes.Contains(textShape))
                    {
                        Canvas parent = textShape.Parent as Telerik.Windows.Controls.Diagrams.DiagramSurface;
                        if (parent != null)
                        {
                            parent.Children.Remove(textShape);
                            this.diagram.ServiceLocator.GetService<Telerik.Windows.Diagrams.Core.ISelectionService<IDiagramItem>>().ClearSelection();
                        }
                    }
                }
            }

Setting diagram.UndoRedoService.UndoBufferSize to 0 after doing some undoable action in diagram does not stop the undo operations.

This is a regression issue. 

Expected: 
UndoBufferSize 0 means no undo possible.  
RedoBufferSize 0 means no redo possible.

Worakround if applicable: Set the UndoBufferSize to 0 after InitializeComponent. (this is if you don't need undo/redo at all).

Using a custom router and gliding connectors may lead to a StackOverflow Exception.

The exception is due to an endless update of the connection Start/End points and the ConnectionPoints.



Resolution: The fix will be included in R2 2017 SP in June 2017.

Generally, avoid using GlidingConnectors and custom Router which calculates intermediate points based on connections' StartPoint/EndPoint. This is а prerequisite of circular dependency between Start/EndPoint and ConnectionPoints. Gliding Connectors essence is to set StartEndPoints and sometimes they are based on the connection points' first and last point.

On the other hand, custom router based on Start/EndPoint makes the opposite- connection points depend on start/end. 

Instead, the client can use the connection.Source.Bounds.Center (Top, Bottom, Left, Right etc) and connection.Target.Bounds.Center(Top, Bottom, Left, Right etc) in a custom router.





Available in LIB version: 2017.2.515

Editing any diagram shape does not take into account the fontsize of the shape.

A possible workaround is to wire to shape's Loaded event as below:
private void RadDiagramTextShape_Loaded(object sender, RoutedEventArgs e)
        {
            RadDiagramTextShape shape = sender as RadDiagramTextShape;
            TextBox tBox = shape.ChildrenOfType<TextBox>().FirstOrDefault();
            tBox.FontSize = shape.FontSize;
        }


Available in LIB version: 2016.3.926

Use Bezier Connection.

Change Start / End Handles with Mouse or with SetBezierHandles method in code.

Rotate/ Drag the connection and notice it is being shifted / its geometry changes unexpectedly.

Possible workaround override the RadDiagramConnection like so:

  public class CustomConnection : RadDiagramConnection
    {
        protected override void OnStartPointChanged(System.Windows.Point newValue, System.Windows.Point oldValue)
        {
            this.ConnectionPoints[0] = new Point(
                    this.ConnectionPoints[0].X - newValue.X + oldValue.X,
                    this.ConnectionPoints[0].Y - newValue.Y + oldValue.Y);         
               
            
            base.OnStartPointChanged(newValue, oldValue);           
        }

        protected override void OnEndPointChanged(Point newValue, Point oldValue)
        {
            this.ConnectionPoints[1] = new Point(
                    this.ConnectionPoints[1].X - newValue.X + oldValue.X,
                    this.ConnectionPoints[1].Y - newValue.Y + oldValue.Y);         
              
            
            base.OnEndPointChanged(newValue, oldValue);           
        }
    }


Available in R3 2016 SP

Available in LIB version: 2016.2.801

Available in R3 2016 Release

-- Add ClearCache method to clear the undo-redo dictionaries used internally

or

-- make the undo-redo dictionaries auto clear when undo-redo stacks are cleared

Available in LIB version: 2016.3.1114
Clear method of Diagram's UndoRedoService now clears the UndoRedo internal cache automatically.  
What's changed ? The public interface IDiagramContainerGeneratorInternal interface now adds ClearCache method:
A) this.Diagram.UndoRedoService.Clear(); will clear the internal undoredo cache which stores model-container relations. Also this will clear the undo/redo command stacks.
B) this.Diagram.ContainerGenerator as GenericContainerGenerator<RadDiagramItem>).ClearCache(); will clear ONLY the undoredo cache.