Sample for changing the orientation of column header in wpf treegrid is included.

Author: AmalRajUmapathySelvam

SfTreeGridDemo.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 14
+VisualStudioVersion = 14.0.25420.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SfTreeGridDemo", "SfTreeGridDemo\SfTreeGridDemo.csproj", "{E17FB357-7AC5-4B42-8818-786FD824B536}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+		Release-XML|Any CPU = Release-XML|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{E17FB357-7AC5-4B42-8818-786FD824B536}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E17FB357-7AC5-4B42-8818-786FD824B536}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E17FB357-7AC5-4B42-8818-786FD824B536}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E17FB357-7AC5-4B42-8818-786FD824B536}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E17FB357-7AC5-4B42-8818-786FD824B536}.Release-XML|Any CPU.ActiveCfg = Release|Any CPU
+		{E17FB357-7AC5-4B42-8818-786FD824B536}.Release-XML|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

SfTreeGridDemo/App.config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+    <startup> 
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6"/>
+    </startup>
+</configuration>

SfTreeGridDemo/App.xaml

@@ -0,0 +1,9 @@
+<Application x:Class="SfTreeGridDemo.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:SfTreeGridDemo"
+             StartupUri="MainWindow.xaml">
+    <Application.Resources>
+         
+    </Application.Resources>
+</Application>

SfTreeGridDemo/App.xaml.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Data;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows;
+
+namespace SfTreeGridDemo
+{
+    /// <summary>
+    /// Interaction logic for App.xaml
+    /// </summary>
+    public partial class App : Application
+    {
+    }
+}

SfTreeGridDemo/Behavior.cs

@@ -0,0 +1,22 @@
+using Syncfusion.UI.Xaml.TreeGrid;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Controls;
+using System.Windows.Interactivity;
+using Syncfusion.UI.Xaml.TreeGrid;
+using System.Windows;
+using Syncfusion.Data;
+
+namespace SfTreeGridDemo
+{
+    class Behavior:Behavior<MainWindow>
+    {
+        protected override void OnAttached()
+        {
+            base.OnAttached();
+        }
+    }
+}

SfTreeGridDemo/Converter.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Data;
+
+namespace SfTreeGridDemo
+{
+    public class MultiCommandConverter : IMultiValueConverter
+    {
+        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
+        {
+            return values.ToList();
+        }
+        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
+        {
+            return null;
+        }
+    }
+}

SfTreeGridDemo/Helper.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Controls;
+using System.Windows.Input;
+
+namespace SfTreeGridDemo
+{
+    public class BaseCommand : ICommand
+    {
+        #region Fields
+
+        readonly Action<object> _execute;
+        readonly Predicate<object> _canExecute;
+       
+
+        #endregion // Fields
+
+        #region Constructors
+
+        public BaseCommand(Action<object> execute)
+            : this(execute, null)
+        {
+        }
+
+        public BaseCommand(Action<object> execute, Predicate<object> canExecute)
+        {
+            if (execute == null)
+                throw new ArgumentNullException("execute");
+
+            _execute = execute;
+            _canExecute = canExecute;
+        }
+
+       
+
+        #endregion // Constructors
+
+        #region ICommand Members
+
+        public bool CanExecute(object parameter)
+        {
+            return _canExecute == null ? true : _canExecute(parameter);
+        }
+
+        public event EventHandler CanExecuteChanged
+        {
+            add { CommandManager.RequerySuggested += value; }
+            remove { CommandManager.RequerySuggested -= value; }
+        }
+
+        public void Execute(object parameter)
+        {
+            _execute(parameter);
+        }
+
+        #endregion // ICommand Members    
+    }
+}