Multi Data Trigger In Xamarin Forms - xamarin

Question

I am attempting to allow click on my button ONLY if the two text fields are not null. However, I am getting the compile error of
Type multi-data trigger not found
Below is my syntax, how should I change it so it executes as desired?
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" >
<ContentPage.Content>
<StackLayout Orientation="Vertical" Padding="30" Spacing="40">
<BoxView HeightRequest="10"/>
<Frame BackgroundColor="#BF043055" HasShadow="False">
<StackLayout Orientation="Vertical" Spacing="10">
<Entry x:Name="Email" Text="{Binding Email}" Placeholder="Email"
PlaceholderColor="Red" HeightRequest="50"
Keyboard="Email" TextColor="Black" />
<Entry x:Name="Password" Text="{Binding Password}" Placeholder="Password"
PlaceholderColor="Red" HeightRequest="50"
IsPassword="True" TextColor="Black" />
</StackLayout>
</Frame>
<Button x:Name="loginbutton" Command="{Binding SubmitCommand}" Text="Login" TextColor="White"
FontAttributes="Bold" FontSize="Large" HorizontalOptions="FillAndExpand"
BackgroundColor="#088da5" >
<Button.Style>
<Style TargetType="{x:Type Button}">
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding ElementName=Email, Path=Text.Length, Mode=OneWay}" Value="0"/>
<Condition Binding="{Binding ElementName=Password, Path=Text.Length, Mode=OneWay}" Value="0"/>
</MultiDataTrigger.Conditions>
<Setter Property="IsEnabled" Value="False"/>
</MultiDataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
</StackLayout>
</ContentPage.Content>
</ContentPage>
EDIT
I edited my syntax to the below but I am getting a compile error of:
No property, bindable property, or event found for 'ElementName', or mismatching type between value and property.
<Button x:Name="loginbutton" Command="{Binding SubmitCommand}" Text="Login" TextColor="White"
FontAttributes="Bold" FontSize="Large" HorizontalOptions="FillAndExpand"
BackgroundColor="#088da5" >
<Button.Style>
<Style TargetType="{x:Type Button}">
<Style.Triggers>
<MultiTrigger TargetType="{x:Type Button}">
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding ElementName=Email, Path=Text.Length, Mode=OneWay}" Value="0"/>
<Condition Binding="{Binding ElementName=Password, Path=Text.Length, Mode=OneWay}" Value="0"/>
</MultiDataTrigger.Conditions>
<Setter Property="IsEnabled" Value="False"/>
</MultiTrigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>

Answer 1

MultiDataTrigger is specific to WPF. Xamarin uses MultiTrigger, which essentially does the same thing. Have a look through this blog post to see how to implement Triggers in Xamarin Forms.