How can I overlay a Card View or a Framed layout on top of another layout in Xamarin Forms? - xaml

Question

I have a situation where I need to "overlay" a grouped set of information, presented by way of a Card (inplemented as a ContentView) on top of a portion of the page header, which is defined in a Grid inside of a FlexLayout. The output should resemble something like the following where the header is the portion in red:
The code for the header is as follows:
<!-- Header -->
<FlexLayout
HeightRequest="108"
AlignItems="Center"
Direction="Column"
BackgroundColor="#D92732">
<Grid VerticalOptions="Center" Margin="0, 30, 0, 0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20"></ColumnDefinition>
<ColumnDefinition Width="40*"></ColumnDefinition>
<ColumnDefinition Width="80*"></ColumnDefinition>
<ColumnDefinition Width="300*"></ColumnDefinition>
<ColumnDefinition Width="80*"></ColumnDefinition>
<ColumnDefinition Width="40*"></ColumnDefinition>
<ColumnDefinition Width="20"></ColumnDefinition>
</Grid.ColumnDefinitions>
<ImageButton Source="Bell.png" Grid.Column="1" BackgroundColor="Transparent"
WidthRequest="37"
HeightRequest="40"
Aspect="AspectFit">
</ImageButton>
<Label
Grid.Column="3"
Text="Payments"
TextColor="#F9F8FA"
FontSize="20"
HeightRequest="40"
HorizontalOptions="Center"
VerticalOptions="Center" VerticalTextAlignment="End">
</Label>
<ImageButton Source="Bell.png" Grid.Column="5" BackgroundColor="Transparent"
WidthRequest="37"
HeightRequest="40"
Aspect="AspectFit">
</ImageButton>
</Grid>
</FlexLayout>

Answer 1

The method I used to solve the problem of having a visual element overlay a portion of another visual element, in this case a Grid overlay a portion of another Grid, is to set the position of the overlay Grid to a specific row and column of the first Grid and then set the Bottom value of the overlay Grid's Margin to a negative number that represents the desired height of the overlay Grid, as seen in the following code and screenshot. Note that I enclosed the overlaid Grid in a Frame which is where I set the negative Bottom Margin value.
<Frame Grid.Row="2" Grid.ColumnSpan="3" Grid.Column="0"
Margin="16,30,16,-310" WidthRequest="343" HeightRequest="300">
<StackLayout HeightRequest="350">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="44*" />
<RowDefinition Height="38*" />
<RowDefinition Height="40*" />
<RowDefinition Height="20*" />
<RowDefinition Height="96*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Label Grid.Row="0"
FontFamily="{StaticResource HNMedium}"
FontSize="{StaticResource Font20}"
HorizontalOptions="Start"
Text="Verify Account"
TextColor="{StaticResource NGIC_DarkGray}"
VerticalOptions="Start" />
<Label Grid.Row="1"
Text="Enter the verification code sent to ******8998"
FontSize="{StaticResource Font16}"
TextColor="{StaticResource NGIC_DarkGrayishBlue}"
FontFamily="{StaticResource HNRegular}"/>
<Entry Grid.Row="2" TextColor="Black" />
<Label Grid.Row="3"
Text="Send a new code"
TextColor="{StaticResource NGIC_Red}"
FontSize="{StaticResource Font14}"
FontFamily="{StaticResource HNMedium}"/>
<StackLayout Grid.Row="4" >
<Button Text="Next"
TextColor="{StaticResource White}"
BackgroundColor="{StaticResource NGIC_Red}"
CornerRadius="15"
WidthRequest="300"
HeightRequest="40"
VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand"
FontFamily="{StaticResource HNBold}"
FontSize="{StaticResource Font14}"/>
<Button Text="Cancel"
TextColor="{StaticResource NGIC_Red}"
BackgroundColor="{StaticResource White}"
CornerRadius="15"
WidthRequest="300"
HeightRequest="40"
VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand"
FontFamily="{StaticResource HNRegular}"
FontSize="{StaticResource Font14}"
BorderColor="{StaticResource NGIC_Red}"
BorderWidth="1"/>
</StackLayout>
</Grid>
</StackLayout>
</Frame>