Merge pull request #1123 from cuiliang/master

Fix #1122

src/Shared/HandyControl_Shared/Tools/Interop/InteropMethods.cs

@@ -306,7 +306,7 @@ namespace HandyControl.Tools.Interop
 
         internal static InteropValues.WINDOWPLACEMENT GetWindowPlacement(IntPtr hwnd)
         {
-            InteropValues.WINDOWPLACEMENT wINDOWPLACEMENT = new InteropValues.WINDOWPLACEMENT();
+            InteropValues.WINDOWPLACEMENT wINDOWPLACEMENT = InteropValues.WINDOWPLACEMENT.Default;
             if (GetWindowPlacement(hwnd, wINDOWPLACEMENT))
             {
                 return wINDOWPLACEMENT;

src/Shared/HandyControl_Shared/Tools/Interop/InteropValues.cs

@@ -364,12 +364,25 @@ namespace HandyControl.Tools.Interop
         [StructLayout(LayoutKind.Sequential)]
         internal struct WINDOWPLACEMENT
         {
-            public int length = Marshal.SizeOf(typeof(WINDOWPLACEMENT));
+            public int length;
             public int flags;
             public SW showCmd;
             public POINT ptMinPosition;
             public POINT ptMaxPosition;
             public RECT rcNormalPosition;
+
+            /// <summary>
+            /// Gets the default (empty) value.
+            /// </summary>
+            public static WINDOWPLACEMENT Default
+            {
+                get
+                {
+                    WINDOWPLACEMENT result = new WINDOWPLACEMENT();
+                    result.length = Marshal.SizeOf(result);
+                    return result;
+                }
+            }
         }
 
         [StructLayout(LayoutKind.Sequential, Pack = 4)]