StyleDefinition normalStyle = this.radRichTextEditor1.Document.StyleRepository[RadDocumentDefaultStyles.NormalWebStyleName];
normalStyle.ParagraphProperties.SpacingAfter = 20;
normalStyle.ParagraphProperties.SpacingBefore = 20;

        public RadForm1()
        {
            InitializeComponent();

                        // This XML contains a simple tree with a root node having 3 children, the first of which is intended to be Bold
            var xml = "<TreeView xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" MultiSelect=\"true\" AllowDragDrop=\"true\" LabelEdit=\"true\" AllowDrop=\"true\">  <Nodes Text=\"New Package\" Expanded=\"true\" ImageKey=\"Package\" Font=\"Microsoft Sans Serif, 8.25pt, style=Bold\">    <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\New Package&lt;/FullName&gt;&lt;ObjectType&gt;Package&lt;/ObjectType&gt;&lt;IsRunnable&gt;False&lt;/IsRunnable&gt;&lt;IsContainer&gt;true&lt;/IsContainer&gt;&lt;/Info&gt;</Tag>    <Nodes Text=\"Query Engine\" ImageKey=\"QueryEngine\" Expanded=\"true\" Font=\"Microsoft Sans Serif, 8.25pt, style=Bold\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Query Engine&lt;/FullName&gt;&lt;ObjectType&gt;QueryEngine&lt;/ObjectType&gt;&lt;IsRunnable&gt;true&lt;/IsRunnable&gt;&lt;IsTableEntity&gt;true&lt;/IsTableEntity&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>    <Nodes Text=\"Connector\" ImageKey=\"Irion.SQLServer\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Connector&lt;/FullName&gt;&lt;ObjectType&gt;DBConnection&lt;/ObjectType&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>    <Nodes Text=\"Connector Link\" ImageKey=\"DatabaseDatalink\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Connector Link&lt;/FullName&gt;&lt;ObjectType&gt;DatabaseDatalink&lt;/ObjectType&gt;&lt;IsRunnable&gt;true&lt;/IsRunnable&gt;&lt;IsTableEntity&gt;true&lt;/IsTableEntity&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>  </Nodes></TreeView>";

            this.radTreeView1.LoadXML(new MemoryStream(System.Text.Encoding.UTF8.GetBytes(xml)));

            //make sure that the following 2 nodes are bold:
            this.radTreeView1.Nodes[0].Nodes[0].Font = new Font("Microsoft Sans Serif", 8.25F, FontStyle.Bold, GraphicsUnit.Point, 0);
            this.radTreeView1.Nodes[0].Nodes[2].Font = new Font("Microsoft Sans Serif", 8.25F, FontStyle.Bold, GraphicsUnit.Point, 0);

            var tvx = this.radTreeView1.TreeViewXml;
        }

var xml = "<TreeView xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" MultiSelect=\"true\" AllowDragDrop=\"true\" LabelEdit=\"true\" AllowDrop=\"true\">  <Nodes Text=\"New Package\" Expanded=\"true\" ImageKey=\"Package\" Font=\"Microsoft Sans Serif; 8,25pt; style=Bold\">    <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\New Package&lt;/FullName&gt;&lt;ObjectType&gt;Package&lt;/ObjectType&gt;&lt;IsRunnable&gt;False&lt;/IsRunnable&gt;&lt;IsContainer&gt;true&lt;/IsContainer&gt;&lt;/Info&gt;</Tag>    <Nodes Text=\"Query Engine\" ImageKey=\"QueryEngine\" Expanded=\"true\" Font=\"Microsoft Sans Serif; 8,25pt; style=Bold\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Query Engine&lt;/FullName&gt;&lt;ObjectType&gt;QueryEngine&lt;/ObjectType&gt;&lt;IsRunnable&gt;true&lt;/IsRunnable&gt;&lt;IsTableEntity&gt;true&lt;/IsTableEntity&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>    <Nodes Text=\"Connector\" ImageKey=\"Irion.SQLServer\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Connector&lt;/FullName&gt;&lt;ObjectType&gt;DBConnection&lt;/ObjectType&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>    <Nodes Text=\"Connector Link\" ImageKey=\"DatabaseDatalink\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Connector Link&lt;/FullName&gt;&lt;ObjectType&gt;DatabaseDatalink&lt;/ObjectType&gt;&lt;IsRunnable&gt;true&lt;/IsRunnable&gt;&lt;IsTableEntity&gt;true&lt;/IsTableEntity&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>  </Nodes></TreeView>";

************** Exception Text **************
System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.WinControls.UI.RadTimePickerElement.set_Value(Object value) in C:\Work\Development\RadControls\RadControlsUI\RadTimePicker\Elements\RadTimePickerElement.cs:line 594
   at Telerik.WinControls.UI.RadTimePickerContentElement.element_Click(Object sender, EventArgs e) in C:\Work\Development\RadControls\RadControlsUI\RadTimePicker\Elements\ContentPart\RadTimePickerContentElement.cs:line 585
   at Telerik.WinControls.RadElement.OnClick(EventArgs e) in C:\Work\Development\RadControls\RadControl\TPF\Element\RadElement.cs:line 5094
   at Telerik.WinControls.RadElement.DoClick(EventArgs e) in C:\Work\Development\RadControls\RadControl\TPF\Element\RadElement.cs:line 5158
   at Telerik.WinControls.RadElement.RaiseBubbleEvent(RadElement sender, RoutedEventArgs args) in C:\Work\Development\RadControls\RadControl\TPF\Element\RadElement.cs:line 4272
   at Telerik.WinControls.RadItem.RaiseBubbleEvent(RadElement sender, RoutedEventArgs args) in C:\Work\Development\RadControls\RadControl\TPF\Element\RadItem.cs:line 779
   at Telerik.WinControls.RadElement.RaiseRoutedEvent(RadElement sender, RoutedEventArgs args) in C:\Work\Development\RadControls\RadControl\TPF\Element\RadElement.cs:line 4179
   at Telerik.WinControls.RadElement.DoMouseUp(MouseEventArgs e) in C:\Work\Development\RadControls\RadControl\TPF\Element\RadElement.cs:line 5271
   at Telerik.WinControls.RadElement.CallDoMouseUp(MouseEventArgs e) in C:\Work\Development\RadControls\RadControl\TPF\Element\RadElement.cs:line 5493
   at Telerik.WinControls.ComponentInputBehavior.OnMouseUp(MouseEventArgs e) in C:\Work\Development\RadControls\RadControl\TPF\Control\ComponentInputBehavior.cs:line 75
   at Telerik.WinControls.RadControl.OnMouseUp(MouseEventArgs e) in C:\Work\Development\RadControls\RadControl\TPF\Control\RadControl.cs:line 1206
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at Telerik.WinControls.RadControl.WndProc(Message& m) in C:\Work\Development\RadControls\RadControl\TPF\Control\RadControl.cs:line 1554
   at Telerik.WinControls.UI.RadPopupControlBase.WndProc(Message& m) in C:\Work\Development\RadControls\RadControlsUI\GenericPopup\RadPopupControlBase.cs:line 795
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

        Timer t = new Timer();

        private void RadTimePicker1_ValueChanged(object sender, EventArgs e)
        {
            if (radTimePicker1.Value == null) return;

            var timeval = ((DateTime)radTimePicker1.Value).TimeOfDay;

            if (timeval == TimeSpan.Zero)
            {
                t = new Timer();
                t.Interval = 500;
                t.Tick += T_Tick; t.Start();
            }
        }

        private void T_Tick(object sender, EventArgs e)
        {
            t.Stop();
            this.radTimePicker1.ValueChanged -= RadTimePicker1_ValueChanged;
            this.radTimePicker1.Value = null;
            this.radTimePicker1.ValueChanged += RadTimePicker1_ValueChanged;
        }

        public RadForm1()
        {
            InitializeComponent();

            DataTable dt = new DataTable();
            dt.Columns.Add("Id");
            dt.Columns.Add("Name");
            for (int i = 0; i < 10; i++)
            {
                dt.Rows.Add(i, "Item" + i); 
            }
            this.radGridView1.DataSource = dt; 
            this.radGridView1.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill; 
             
            this.radGridView1.CellValidating += radGridView1_CellValidating;
        }

        private void radGridView1_CellValidating(object sender, CellValidatingEventArgs e)
        {
            if (e.Column.Index == 0 && e.ActiveEditor != null && e.Value + "" == "1")
            { 
                e.Cancel = true;
                RadMessageBox.Show("IncorrectValue");
            }
        }

        public class CustomGridView : RadGridView
        {
            public override string ThemeClassName  
            { 
                get 
                { 
                    return typeof(RadGridView).FullName;  
                }
            }

            protected override void OnMouseDown(MouseEventArgs e)
            {
             RadScrollBarElement scrollbar=   this.GridViewElement.ElementTree.GetElementAtPoint ( e.Location) as RadScrollBarElement;
             if (scrollbar!=null && this.IsInEditMode)
             {
                    this.EditorManager.CloseEditorWhenValidationFails = false;
                    this.EditorManager.CloseEditor();
                    return;
             }
                base.OnMouseDown(e);
            }
        }