Merge pull request #2355 from mcooley/recthelper-sizehelper-fixes

Corrections to RectHelper and SizeHelper's definition of "empty"

Author: jwmsft

windows.ui.xaml/recthelper_empty.md

@@ -11,13 +11,13 @@ public Windows.Foundation.Rect Empty { get; }
 
 ## -description
 
-Gets a static [Rect](../windows.foundation/rect.md) value where the [Rect](../windows.foundation/rect.md) has no size or position (all values 0). C# and Microsoft Visual Basic code should use [Rect.Empty](/dotnet/api/windows.foundation.rect.empty?view=dotnet-uwp-10.0&preserve-view=true) instead.
+Gets a static [Rect](../windows.foundation/rect.md) value where the [Rect](../windows.foundation/rect.md) has no size or position. C# and Microsoft Visual Basic code should use [Rect.Empty](/dotnet/api/windows.foundation.rect.empty?view=dotnet-uwp-10.0&preserve-view=true) instead.
 
 
 
 ## -property-value
 
-A [Rect](../windows.foundation/rect.md) with all values as 0.
+A [Rect](../windows.foundation/rect.md) with X and Y set to positive infinity, and Width and Height set to negative infinity.
 
 ## -remarks
 

windows.ui.xaml/recthelper_getbottom_1066401735.md

@@ -11,7 +11,7 @@ public float GetBottom(Windows.Foundation.Rect target)
 
 ## -description
 
-Gets a "Bottom" value for the specified [Rect](../windows.foundation/rect.md). So long as **Height** is positive, "Bottom" is evaluated as **Y** + **Height**. C# and Microsoft Visual Basic code should use [Rect.Bottom](/dotnet/api/windows.foundation.rect.bottom?view=dotnet-uwp-10.0&preserve-view=true) instead.
+Gets a "Bottom" value for the specified [Rect](../windows.foundation/rect.md). So long as the Rect is not the [Empty](recthelper_empty.md) Rect, "Bottom" is evaluated as **Y** + **Height**. C# and Microsoft Visual Basic code should use [Rect.Bottom](/dotnet/api/windows.foundation.rect.bottom?view=dotnet-uwp-10.0&preserve-view=true) instead.
 
 
 

windows.ui.xaml/recthelper_getisempty_1110221055.md

@@ -27,6 +27,8 @@ The [Rect](../windows.foundation/rect.md) to evaluate.
 
 ## -remarks
 
+Do not use this method to test for zero area; a rectangle with zero area is not necessarily the [Empty](recthelper_empty.md) rectangle. For more information, see the [Empty](recthelper_empty.md) property.
+
 ## -examples
 
 ## -see-also

windows.ui.xaml/recthelper_getleft_1023490401.md

@@ -11,7 +11,7 @@ public float GetLeft(Windows.Foundation.Rect target)
 
 ## -description
 
-Gets a "Left" value for the specified [Rect](../windows.foundation/rect.md). So long as **Width** is positive, "Left" is evaluated as **X**. C# and Microsoft Visual Basic code should use [Rect.Left](/dotnet/api/windows.foundation.rect.left?view=dotnet-uwp-10.0&preserve-view=true) instead.
+Gets a "Left" value for the specified [Rect](../windows.foundation/rect.md). So long as the Rect is not the [Empty](recthelper_empty.md) Rect, "Left" is evaluated as **X**. C# and Microsoft Visual Basic code should use [Rect.Left](/dotnet/api/windows.foundation.rect.left?view=dotnet-uwp-10.0&preserve-view=true) instead.
 
 
 

windows.ui.xaml/recthelper_getright_1384154527.md

@@ -11,7 +11,7 @@ public float GetRight(Windows.Foundation.Rect target)
 
 ## -description
 
-Gets a "Right" value for the specified [Rect](../windows.foundation/rect.md). So long as **Width** is positive, "Right" is evaluated as **X** + **Width**. C# and Microsoft Visual Basic code should use [Rect.Right](/dotnet/api/windows.foundation.rect.right?view=dotnet-uwp-10.0&preserve-view=true) instead.
+Gets a "Right" value for the specified [Rect](../windows.foundation/rect.md). So long as the Rect is not the [Empty](recthelper_empty.md) Rect, "Right" is evaluated as **X** + **Width**. C# and Microsoft Visual Basic code should use [Rect.Right](/dotnet/api/windows.foundation.rect.right?view=dotnet-uwp-10.0&preserve-view=true) instead.
 
 
 

windows.ui.xaml/recthelper_gettop_1602274045.md

@@ -11,7 +11,7 @@ public float GetTop(Windows.Foundation.Rect target)
 
 ## -description
 
-Gets a "Top" value for the specified [Rect](../windows.foundation/rect.md). So long as **Height** is positive, "Top" is evaluated as **Y**. C# and Microsoft Visual Basic code should use [Rect.Top](/dotnet/api/windows.foundation.rect.top?view=dotnet-uwp-10.0&preserve-view=true) instead.
+Gets a "Top" value for the specified [Rect](../windows.foundation/rect.md). So long as the Rect is not the [Empty](recthelper_empty.md) Rect, "Top" is evaluated as **Y**. C# and Microsoft Visual Basic code should use [Rect.Top](/dotnet/api/windows.foundation.rect.top?view=dotnet-uwp-10.0&preserve-view=true) instead.
 
 
 

windows.ui.xaml/sizehelper_empty.md

@@ -11,13 +11,13 @@ public Windows.Foundation.Size Empty { get; }
 
 ## -description
 
-Gets a static [Size](../windows.foundation/size.md) value where the [Size](../windows.foundation/size.md) has no height or width (all values 0). C# and Microsoft Visual Basic code should use [Size.Empty](/dotnet/api/windows.foundation.size.empty?view=dotnet-uwp-10.0&preserve-view=true) instead.
+Gets a static [Size](../windows.foundation/size.md) value where the [Size](../windows.foundation/size.md) has no height or width. C# and Microsoft Visual Basic code should use [Size.Empty](/dotnet/api/windows.foundation.size.empty?view=dotnet-uwp-10.0&preserve-view=true) instead.
 
 
 
 ## -property-value
 
-A [Size](../windows.foundation/size.md) with all values as 0.
+A [Size](../windows.foundation/size.md) with Width and Height set to negative infinity.
 
 ## -remarks
 

windows.ui.xaml/sizehelper_getisempty_1023510010.md

@@ -27,6 +27,8 @@ The [Size](../windows.foundation/size.md) to evaluate.
 
 ## -remarks
 
+Do not use this method to test for zero area; a size with zero area is not necessarily the [Empty](sizehelper_empty.md) size. For more information, see the [Empty](sizehelper_empty.md) property.
+
 ## -examples
 
 ## -see-also