Xamarin Forms: ImageButton border ignored on Android - xaml

Question

I have a StackLayout containing some ImageButtons, the buttons have a BorderWidth of 5.
On UWP, the border appears with the image scaled to fit inside. On Android, the border doesn't appear at all, and the image flows into it space.
UWP (correct):
Android (no border):
My XAML looks like this
<StackLayout
x:Name="titlebar"
Orientation="Horizontal"
BackgroundColor="{x:DynamicResource TitleBarColor}">
...
<ImageButton
x:Name="menu"
HeightRequest="25" WidthRequest="25"
HorizontalOptions="End"
BorderWidth="5"
BackgroundColor="{x:DynamicResource TitleBarColor}"
Source="{local:ImageResource CloudTest.Assets.icons.more_menu_white.png}"
Clicked="OnMenuClicked" />
</StackLayout>

Answer 1

In Android, I've found that it only works if you set both BorderWidth and BorderColor(could not Transparent).
and you also could set the Padding or Marginto the ImageButton to achieve to the effect.
<ImageButton
x:Name="menu"
HeightRequest="25" WidthRequest="25"
HorizontalOptions="End"
Padding ="5" //or Margin ="5"
BackgroundColor="{x:DynamicResource TitleBarColor}"
Source="{local:ImageResource CloudTest.Assets.icons.more_menu_white.png}"
Clicked="OnMenuClicked" />
Update (The yellow area is your ImageButton):
When using Margin,refers to the distance between the control and a sibling control :
Padding ,refers to the internal content of the control, such as the margin of the text/image distance from the control
so when you use the padding,you will see the space inside the image and when you use the margin,the space outside the image .