add function codes

src/Shared/HandyControl_Shared/Data/HwndWrapper.cs

@@ -0,0 +1,102 @@
+using System;
+using System.Runtime.InteropServices;
+using HandyControl.Tools.Interop;
+
+namespace HandyControl.Data
+{
+    public abstract class HwndWrapper : DisposableObject
+    {
+        private IntPtr _handle;
+        
+        private bool _isHandleCreationAllowed = true;
+        
+        private ushort _wndClassAtom;
+        
+        private Delegate _wndProc;
+
+        protected ushort WindowClassAtom
+        {
+            get
+            {
+                if (_wndClassAtom == 0) _wndClassAtom = CreateWindowClassCore();
+                return _wndClassAtom;
+            }
+        }
+
+        public IntPtr Handle
+        {
+            get
+            {
+                EnsureHandle();
+                return _handle;
+            }
+        }
+
+        protected virtual bool IsWindowSubclassed => false;
+
+        protected virtual ushort CreateWindowClassCore() => RegisterClass(Guid.NewGuid().ToString());
+
+        protected virtual void DestroyWindowClassCore()
+        {
+            if (_wndClassAtom != 0)
+            {
+                var moduleHandle = InteropMethods.GetModuleHandle(null);
+                InteropMethods.UnregisterClass(new IntPtr(_wndClassAtom), moduleHandle);
+                _wndClassAtom = 0;
+            }
+        }
+
+        protected ushort RegisterClass(string className)
+        {
+            var wndClass = default(InteropValues.WNDCLASS);
+            wndClass.cbClsExtra = 0;
+            wndClass.cbWndExtra = 0;
+            wndClass.hbrBackground = IntPtr.Zero;
+            wndClass.hCursor = IntPtr.Zero;
+            wndClass.hIcon = IntPtr.Zero;
+            wndClass.lpfnWndProc = _wndProc = new InteropValues.WndProc(WndProc);
+            wndClass.lpszClassName = className;
+            wndClass.lpszMenuName = null;
+            wndClass.style = 0u;
+            return InteropMethods.RegisterClass(ref wndClass);
+        }
+
+        private void SubclassWndProc()
+        {
+            _wndProc = new InteropValues.WndProc(WndProc);
+            InteropMethods.SetWindowLong(_handle, -4, Marshal.GetFunctionPointerForDelegate(_wndProc));
+        }
+
+        protected abstract IntPtr CreateWindowCore();
+
+        protected virtual void DestroyWindowCore()
+        {
+            if (_handle != IntPtr.Zero)
+            {
+                InteropMethods.DestroyWindow(_handle);
+                _handle = IntPtr.Zero;
+            }
+        }
+
+        protected virtual IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam) =>
+            InteropMethods.DefWindowProc(hwnd, msg, wParam, lParam);
+
+        public void EnsureHandle()
+        {
+            if (_handle == IntPtr.Zero)
+            {
+                if (!_isHandleCreationAllowed) return;
+                _isHandleCreationAllowed = false;
+                _handle = CreateWindowCore();
+                if (IsWindowSubclassed) SubclassWndProc();
+            }
+        }
+
+        protected override void DisposeNativeResources()
+        {
+            _isHandleCreationAllowed = false;
+            DestroyWindowCore();
+            DestroyWindowClassCore();
+        }
+    }
+}