I am trying to have two entry that are numbers if they are numbers enable the button. If not enable the button. I created a sample app to test this.

What i tried so far created a class that checks if it is a double and changes the text to green if double or red if not. That works. I tried muititrgger conditions in the button. My thought was to check if the entry text color was red or green to control the button. I am placing my code below.

public class NumericValidationTriggerAction : TriggerAction<Entry>
{
    
    protected override void Invoke (Entry entry)
    {
        double result;
        bool isValid = Double.TryParse(entry.Text, out result);
        entry.TextColor = isValid ? Colors.Black : Colors.Red;
       
    }
}

<StackLayout>
    <Label FontSize="20"
           Text="EventTrigger Example"/>

    <Label Text="Text must be a valid double or it will turn red"/>
    <Entry x:Name="email" 
        Placeholder="Enter a System.Double"
           >
        <Entry.Triggers>
            <EventTrigger Event="TextChanged">
                <local:NumericValidationTriggerAction/>
            </EventTrigger>
        </Entry.Triggers>
    </Entry>

    <Button
        Text="Save"
        IsEnabled="False">
        <Button.Triggers>
            <MultiTrigger TargetType="Button">
                <MultiTrigger.Conditions>
                    <BindingCondition Binding="{Binding Source={x:Reference email}, Path=Double.TryParse.email}" Value="Green"/>
                </MultiTrigger.Conditions>
            </MultiTrigger>
        </Button.Triggers>
    </Button>
</StackLayout>