Embedding/hosting

SetParent(appWin, this.Handle);

<TabItem Name="tab1" Header="Tab 1" Foreground="White" FontWeight="Bold" FontSize="20">
                   <my:Window_Host_Helper x:Name="host"></my:Window_Host_Helper>
               </TabItem>

public class Window_Host_Helper : System.Windows.Controls.ContentControl
    {
        [DllImport("user32.dll")]
        static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
        [DllImport("user32.dll")]
        static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X,
           int Y, int cx, int cy, uint uFlags);
        [DllImport("user32.dll")]
        static extern int SetWindowLong(IntPtr hWnd, int nIndex, IntPtr dwNewLong);
        [DllImport("user32.dll", SetLastError = true)]
        static extern int GetWindowLong(IntPtr hWnd, int nIndex);
        [DllImport("user32.dll")]
          public static extern int EnumWindows(EnumWindowsProc ewp, int lParam);
        
        const UInt32 SWP_FRAMECHANGED = 0x0020;  
        static readonly int GWL_STYLE = (-16);
        public const uint WS_CAPTION = 0x00C00000;
        public const uint WS_THICKFRAME = 0x00040000;
        public const uint WS_CLIPCHILDREN = 0x02000000;
        public const uint WS_OVERLAPPED = 0x00000000;
        public delegate bool EnumWindowsProc(IntPtr hWnd, int lParam);

        private WindowsFormsHost host = new WindowsFormsHost();
        private System.Windows.Forms.Panel panel = new System.Windows.Forms.Panel();
        private IntPtr windowHandle;

        public System.Diagnostics.Process Process
        {
            set
            {
                try
                {
                    value.Start();
                   
                    if (!value.WaitForInputIdle(3000))
                    {
                        throw new ArgumentException();   
                    }
                    //Important to let the thread sleep for a while
                    System.Threading.Thread.Sleep(1000);
                    this.windowHandle = value.MainWindowHandle;
                    int dwStyle = GetWindowLong(this.windowHandle, GWL_STYLE);
                    SetWindowLong(this.windowHandle, GWL_STYLE, new IntPtr(dwStyle &
                    ~WS_CAPTION & ~WS_THICKFRAME));
                    SetWindowPos(this.windowHandle, IntPtr.Zero, 0, 0, Convert.ToInt32(Math.Floor(this.ActualWidth)), Convert.ToInt32(Math.Floor(this.ActualHeight)), SWP_FRAMECHANGED);
                    SetParent(this.windowHandle, panel.Handle);
                    
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message.ToString());
                }
            }
        }

        public Window_Host_Helper()
        {
            this.Content = host;
            this.panel.CreateControl();
            host.Child = this.panel;
        }

        protected override void OnPropertyChanged(System.Windows.DependencyPropertyChangedEventArgs e)
        {
            base.OnPropertyChanged(e);
        }
        protected override System.Windows.Size ArrangeOverride(System.Windows.Size arrangeBounds)
        {
            base.ArrangeOverride(arrangeBounds);
            SetWindowPos(this.windowHandle, IntPtr.Zero, 0, 0, Convert.ToInt32(Math.Floor(arrangeBounds.Width)), Convert.ToInt32(Math.Floor(arrangeBounds.Height)), 0);
            return arrangeBounds;
        }
        protected override void OnContentChanged(object oldContent, object newContent)
        {
            this.Content = this.host;
            
        }

        
    }

Process p = new Process();
           p.StartInfo = new ProcessStartInfo("C:\\Program Files (x86)\\VideoLAN\\VLC\\vlc.exe");
           host.Process = p;