Add GetLParam<T> and GetLParamRef<T>

src/Common/src/NativeMethods.cs

@@ -4044,7 +4044,7 @@ public struct WINDOWPOS {
         }
 
         [StructLayout(LayoutKind.Sequential)]
-        public unsafe struct HDLAYOUT {
+        public struct HDLAYOUT {
             public IntPtr       prc;        // pointer to a RECT
             public IntPtr       pwpos;      // pointer to a WINDOWPOS
         }
@@ -4374,7 +4374,7 @@ public struct LVITEM {
             public int      cColumns; // tile view columns
             public IntPtr   puColumns;
 
-            public unsafe void Reset() {
+            public void Reset() {
                 pszText = null;
                 mask = 0;
                 iItem = 0;

src/System.Windows.Forms/src/System/Windows/Forms/Control.cs

@@ -12842,15 +12842,15 @@ private void WmMove(ref Message m) {
         ///     Handles the WM_NOTIFY message
         /// </devdoc>
         /// <internalonly/>
-        private unsafe void WmNotify(ref Message m) {
-            NativeMethods.NMHDR* nmhdr = (NativeMethods.NMHDR*)m.LParam;
-            if (!ReflectMessage(nmhdr->hwndFrom,ref m)) {
-                if(nmhdr->code == NativeMethods.TTN_SHOW) {
-                    m.Result = UnsafeNativeMethods.SendMessage(new HandleRef(null, nmhdr->hwndFrom), Interop.WindowMessages.WM_REFLECT + m.Msg, m.WParam, m.LParam);
+        private void WmNotify(ref Message m) {
+            ref readonly NativeMethods.NMHDR nmhdr = ref m.GetLParamRef<NativeMethods.NMHDR>();
+            if (!ReflectMessage(nmhdr.hwndFrom,ref m)) {
+                if(nmhdr.code == NativeMethods.TTN_SHOW) {
+                    m.Result = UnsafeNativeMethods.SendMessage(new HandleRef(null, nmhdr.hwndFrom), Interop.WindowMessages.WM_REFLECT + m.Msg, m.WParam, m.LParam);
                     return;
                 }
-                if(nmhdr->code == NativeMethods.TTN_POP) {
-                    UnsafeNativeMethods.SendMessage(new HandleRef(null, nmhdr->hwndFrom), Interop.WindowMessages.WM_REFLECT + m.Msg, m.WParam, m.LParam);
+                if(nmhdr.code == NativeMethods.TTN_POP) {
+                    UnsafeNativeMethods.SendMessage(new HandleRef(null, nmhdr.hwndFrom), Interop.WindowMessages.WM_REFLECT + m.Msg, m.WParam, m.LParam);
                 }
 
                 DefWndProc(ref m);
@@ -13089,27 +13089,27 @@ private void WmSetCursor(ref Message m) {
         ///     Handles the WM_WINDOWPOSCHANGING message
         /// </devdoc>
         /// <internalonly/>
-        private unsafe void WmWindowPosChanging(ref Message m) {
+        private void WmWindowPosChanging(ref Message m) {
 
             // We let this fall through to defwndproc unless we are being surfaced as
             // an ActiveX control.  In that case, we must let the ActiveX side of things
             // manipulate our bounds here.
             //
             if (IsActiveX) {
-                NativeMethods.WINDOWPOS* wp = (NativeMethods.WINDOWPOS *)m.LParam;
+                ref NativeMethods.WINDOWPOS wp = ref m.GetLParamRef<NativeMethods.WINDOWPOS>();
                 // Only call UpdateBounds if the new bounds are different.
                 //
                 bool different = false;
 
-                if ((wp->flags & NativeMethods.SWP_NOMOVE) == 0 && (wp->x != Left || wp->y != Top)) {
+                if ((wp.flags & NativeMethods.SWP_NOMOVE) == 0 && (wp.x != Left || wp.y != Top)) {
                     different = true;
                 }
-                if ((wp->flags & NativeMethods.SWP_NOSIZE) == 0 && (wp->cx != Width || wp->cy != Height)) {
+                if ((wp.flags & NativeMethods.SWP_NOSIZE) == 0 && (wp.cx != Width || wp.cy != Height)) {
                     different = true;
                 }
 
                 if (different) {
-                    ActiveXUpdateBounds(ref wp->x, ref wp->y, ref wp->cx, ref wp->cy, wp->flags);
+                    ActiveXUpdateBounds(ref wp.x, ref wp.y, ref wp.cx, ref wp.cy, wp.flags);
                 }
             }
 
@@ -13323,15 +13323,15 @@ private void WmUpdateUIState(ref Message m) {
         ///     Handles the WM_WINDOWPOSCHANGED message
         /// </devdoc>
         /// <internalonly/>
-        private unsafe void WmWindowPosChanged(ref Message m) {
+        private void WmWindowPosChanged(ref Message m) {
             DefWndProc(ref m);
             // Update new size / position
             UpdateBounds();
             if (parent != null && UnsafeNativeMethods.GetParent(new HandleRef(window, InternalHandle)) == parent.InternalHandle &&
                 (state & STATE_NOZORDER) == 0) {
 
-                NativeMethods.WINDOWPOS* wp = (NativeMethods.WINDOWPOS *)m.LParam;
-                if ((wp->flags & NativeMethods.SWP_NOZORDER) == 0) {
+                ref readonly NativeMethods.WINDOWPOS wp = ref m.GetLParamRef<NativeMethods.WINDOWPOS>();
+                if ((wp.flags & NativeMethods.SWP_NOZORDER) == 0) {
                     parent.UpdateChildControlIndex(this);
                 }
             }

src/System.Windows.Forms/src/System/Windows/Forms/DataGridViewMethods.cs

@@ -29802,22 +29802,22 @@ private void WmGetDlgCode(ref Message m)
             }
         }
 
-        private unsafe bool WmNotify(ref Message m)
+        private bool WmNotify(ref Message m)
         {
             if (m.LParam == IntPtr.Zero)
             {
                 return false;
             }
 
-            NativeMethods.NMHDR* nmhdr = (NativeMethods.NMHDR *)m.LParam;
-            if (nmhdr->code == NativeMethods.TTN_GETDISPINFO && !DesignMode)
+            ref readonly NativeMethods.NMHDR nmhdr = ref m.GetLParamRef<NativeMethods.NMHDR>();
+            if (nmhdr.code == NativeMethods.TTN_GETDISPINFO && !DesignMode)
             {
                 string toolTip = this.ToolTipPrivate;
 
                 if (!string.IsNullOrEmpty(toolTip))
                 {
                     // MSDN: Setting the max width has the added benefit of enabling multiline tool tips!
-                    UnsafeNativeMethods.SendMessage(new HandleRef(this, nmhdr->hwndFrom), NativeMethods.TTM_SETMAXTIPWIDTH, 0, SystemInformation.MaxWindowTrackSize.Width);
+                    UnsafeNativeMethods.SendMessage(new HandleRef(this, nmhdr.hwndFrom), NativeMethods.TTM_SETMAXTIPWIDTH, 0, SystemInformation.MaxWindowTrackSize.Width);
                     NativeMethods.TOOLTIPTEXT ttt = (NativeMethods.TOOLTIPTEXT) m.GetLParam(typeof(NativeMethods.TOOLTIPTEXT));
 
                     ttt.lpszText = toolTip;

src/System.Windows.Forms/src/System/Windows/Forms/DateTimePicker.cs

@@ -1621,7 +1621,7 @@ protected override void OnSystemColorsChanged(EventArgs e) {
         private void WmReflectCommand(ref Message m) {
             if (m.HWnd == Handle) {
 
-                NativeMethods.NMHDR nmhdr = (NativeMethods.NMHDR)m.GetLParam(typeof(NativeMethods.NMHDR));
+                ref readonly NativeMethods.NMHDR nmhdr = ref m.GetLParamRef<NativeMethods.NMHDR>();
                 switch (nmhdr.code) {
                     case NativeMethods.DTN_CLOSEUP:
                         WmCloseUp(ref m);

src/System.Windows.Forms/src/System/Windows/Forms/Design/ComponentEditorForm.cs

@@ -840,7 +840,7 @@ private void FillRectDither(IntPtr dc, NativeMethods.RECT rc) {
 
             protected override void WndProc(ref Message m) {
                 if (m.Msg == Interop.WindowMessages.WM_REFLECT + Interop.WindowMessages.WM_NOTIFY) {
-                    NativeMethods.NMHDR nmh = (NativeMethods.NMHDR)m.GetLParam(typeof(NativeMethods.NMHDR));
+                    ref readonly NativeMethods.NMHDR nmh = ref m.GetLParamRef<NativeMethods.NMHDR>();
                     if (nmh.code == NativeMethods.NM_CUSTOMDRAW) {
                         OnCustomDraw(ref m);
                         return;

src/System.Windows.Forms/src/System/Windows/Forms/DpiChangedEventArgs.cs

@@ -5,7 +5,6 @@
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Drawing;
-using System.Runtime.InteropServices;
 
 namespace System.Windows.Forms
 {
@@ -22,7 +21,7 @@ internal DpiChangedEventArgs(int old, Message m)
             DeviceDpiOld = old;
             DeviceDpiNew = NativeMethods.Util.SignedLOWORD(m.WParam);
             Debug.Assert(NativeMethods.Util.SignedHIWORD(m.WParam) == DeviceDpiNew, "Non-square pixels!");
-            NativeMethods.RECT suggestedRect = Marshal.PtrToStructure<NativeMethods.RECT>(m.LParam);
+            ref readonly NativeMethods.RECT suggestedRect = ref m.GetLParamRef<NativeMethods.RECT>();
             SuggestedRectangle = Rectangle.FromLTRB(suggestedRect.left, suggestedRect.top, suggestedRect.right, suggestedRect.bottom);
         }
 

src/System.Windows.Forms/src/System/Windows/Forms/ErrorProvider.cs

@@ -1254,7 +1254,7 @@ public void Update(bool timerCaused) {
             protected override void WndProc(ref Message m) {
                 switch (m.Msg) {
                     case Interop.WindowMessages.WM_NOTIFY:
-                        NativeMethods.NMHDR nmhdr = (NativeMethods.NMHDR)m.GetLParam(typeof(NativeMethods.NMHDR));
+                        ref readonly NativeMethods.NMHDR nmhdr = ref m.GetLParamRef<NativeMethods.NMHDR>();
                         if (nmhdr.code == NativeMethods.TTN_SHOW || nmhdr.code == NativeMethods.TTN_POP)
                         {
                             OnToolTipVisibilityChanging(nmhdr.idFrom, nmhdr.code == NativeMethods.TTN_SHOW);

src/System.Windows.Forms/src/System/Windows/Forms/ImageList.cs

@@ -627,21 +627,19 @@ private void CopyBitmapData(BitmapData sourceData, BitmapData targetData) {
             // do the actual copy
             int offsetSrc = 0;
             int offsetDest = 0;
-            unsafe {
-                for (int i = 0; i < targetData.Height; i++)
-                {
-                    IntPtr srcPtr, destPtr;
-                    if (IntPtr.Size == 4) {
-                        srcPtr = new IntPtr(sourceData.Scan0.ToInt32() + offsetSrc);
-                        destPtr = new IntPtr(targetData.Scan0.ToInt32() + offsetDest);
-                    } else {
-                        srcPtr = new IntPtr(sourceData.Scan0.ToInt64() + offsetSrc);
-                        destPtr = new IntPtr(targetData.Scan0.ToInt64() + offsetDest);
-                    }
-                    UnsafeNativeMethods.CopyMemory(new HandleRef(this, destPtr), new HandleRef(this, srcPtr), Math.Abs(targetData.Stride)); 
-                    offsetSrc += sourceData.Stride;
-                    offsetDest += targetData.Stride;
+            for (int i = 0; i < targetData.Height; i++)
+            {
+                IntPtr srcPtr, destPtr;
+                if (IntPtr.Size == 4) {
+                    srcPtr = new IntPtr(sourceData.Scan0.ToInt32() + offsetSrc);
+                    destPtr = new IntPtr(targetData.Scan0.ToInt32() + offsetDest);
+                } else {
+                    srcPtr = new IntPtr(sourceData.Scan0.ToInt64() + offsetSrc);
+                    destPtr = new IntPtr(targetData.Scan0.ToInt64() + offsetDest);
                 }
+                UnsafeNativeMethods.CopyMemory(new HandleRef(this, destPtr), new HandleRef(this, srcPtr), Math.Abs(targetData.Stride)); 
+                offsetSrc += sourceData.Stride;
+                offsetDest += targetData.Stride;
             }
         }