WPF页面嵌入exe文件，怎样控制嵌入文件窗体的缩放比例？

[DllImport("user32.dll")]   

        private static extern int SetParent(IntPtr hWndChild, IntPtr hWndParent);   

        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]   

        private static extern uint SetWindowLong(IntPtr hwnd, int nIndex, uint newLong);   

        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]   

        private static extern uint GetWindowLong(IntPtr hwnd, int nIndex);   

       

        [DllImport("user32.dll")]   

        private static extern int EnumWindows(CallBackPtr callPtr, ref WindowInfo WndInfoRef);   

        [DllImport("User32.dll")]   

        static extern int GetWindowText(IntPtr handle, StringBuilder text, int MaxLen);   

        [DllImport("user32.dll")]   

        public static extern int GetWindowRect(IntPtr hwnd, ref RECT rc);   

        internal const int  

            GWL_WNDPROC = (-4),   

            GWL_HINSTANCE = (-6),   

            GWL_HWNDPARENT = (-8),   

            GWL_STYLE = (-16),   

            GWL_EXSTYLE = (-20),   

            GWL_USERDATA = (-21),   

            GWL_ID = (-12);   

        internal const uint  

              WS_CHILD = 0x40000000,   

              WS_VISIBLE = 0x10000000,   

              LBS_NOTIFY = 0x00000001,   

              HOST_ID = 0x00000002,   

              LISTBOX_ID = 0x00000001,   

              WS_VSCROLL = 0x00200000,   

              WS_BORDER = 0x00800000,   

              WS_POPUP = 0x80000000;   

        private const int HWND_TOP = 0x0;   

        private const int WM_COMMAND = 0x0112;   

        private const int WM_QT_PAINT = 0xC2DC;   

        private const int WM_PAINT = 0x000F;   

        private const int WM_SIZE = 0x0005;   

        private const int SWP_FRAMECHANGED = 0x0020;   

        private Border WndHoster;   

        private double screenW, screenH;   

        private System.Diagnostics.Process appProc;   

        private uint oldStyle;   

        private IntPtr hwndHost;   

        private String appPath;   

        public EmbeddedApp(Border b, double sW, double sH, String p, String f)   

        {   

            WndHoster = b;   

            screenH = sH;   

            screenW = sW;   

            appPath = p;   

            WinInfo = new WindowInfo();   

            WinInfo.winTitle = f;   

        }

        protected override HandleRef BuildWindowCore( HandleRef hwndParent )

        {

            hwndHost = FindTheWindow( );

            //if (hwndHost == null)   

            //{   

            appProc = new System.Diagnostics.Process( );

            appProc.StartInfo.FileName = appPath;

            appProc.Start( );

            Thread.Sleep( 1000 );

            hwndHost = FindTheWindow( );

            //}   

            // 嵌入在HwnHost中的窗口必须要 设置为WS_CHILD风格    

            oldStyle = GetWindowLong( hwndHost , GWL_STYLE );

            uint newStyle = oldStyle;

            //WS_CHILD和WS_POPUP不能同时存在。有些Win32窗口，比如QQ的窗口，有WS_POPUP属性，这样嵌入的时候会导致程序错误   

            newStyle |= WS_CHILD;

            newStyle &= ~WS_POPUP;

            newStyle &= ~WS_BORDER;

            SetWindowLong( hwndHost , GWL_STYLE , newStyle );

            //将窗口居中，实际上是将窗口的容器居中   

            RePosWindow( WndHoster , WndHoster.Width , WndHoster.Height );

            

            //将netterm的父窗口设置为HwndHost    

            SetParent( hwndHost , hwndParent.Handle );

            return new HandleRef( this , hwndHost );

        }

        protected override void DestroyWindowCore(System.Runtime.InteropServices.HandleRef hwnd)   

        {   

            SetWindowLong(hwndHost, GWL_STYLE, oldStyle);   

            SetParent(hwndHost, (IntPtr)0);   

        }   

  

        [StructLayout(LayoutKind.Sequential)]   

        public struct RECT   

        {   

            public int left;   

            public int top;   

            public int right;   

            public int bottom;   

        }   

        [StructLayout(LayoutKind.Sequential)]   

        public struct WindowInfo   

        {   

            public String winTitle;   

            public RECT r;   

            public IntPtr hwnd;   

        }   

        public delegate bool CallBackPtr(IntPtr hwnd, ref WindowInfo WndInfoRef);   

        private static CallBackPtr callBackPtr;   

        private WindowInfo WinInfo;   

        public static bool CallBackProc(IntPtr hwnd, ref WindowInfo WndInfoRef)   

        {   

            StringBuilder str = new StringBuilder(512);   

            GetWindowText(hwnd, str, str.Capacity);   

            if (str.ToString().IndexOf(WndInfoRef.winTitle, 0) >= 0)   

            {   

                WndInfoRef.hwnd = hwnd;   

                GetWindowRect(hwnd, ref (WndInfoRef.r));   

            }   

               

            return true;   

        }   

        public IntPtr FindTheWindow()   

        {   

            callBackPtr = new CallBackPtr(CallBackProc);   

            EnumWindows(callBackPtr, ref WinInfo);   

            return WinInfo.hwnd;   

        }   

        public void RePosWindow(Border b, double screenW, double screenH)   

        {

            double width = WinInfo.r.right - WinInfo.r.left;

            double height = WinInfo.r.bottom - WinInfo.r.top;

            

            double left = ( screenW - width ) / 2;

            double right = ( screenW - width ) / 2;

            double top = ( screenH - height ) / 2;

            double bottom = ( screenH - height ) / 2;   



            //double width = 300;

            //double height = 300;

            //double left = 50;

            //double right = 50;

            //double top = 50;

            //double bottom = 50; 



            b.Margin = new Thickness(left, top, right, bottom);  

        }   







            //加载.exe文件

            String path=Environment.CurrentDirectory + @"\QQ.exe";

            EmbeddedApp ea = new EmbeddedApp( WndHost , 100 , 100 , path , "photomain" );

            WndHost.Child = ea;



            System.Threading.Thread.Sleep( 10000 );