How to call function from Binding Command in xamarin forms

Question

I am wondering how I can call a function from a command in xamarin forms. I am currently using https://github.com/robinmanuelthiel/swipecards to set up a stack of swipe-able cards. I am able to see that in the meta file there are two bindable properties to handle left and right swipes.

Snip from the Meta file:

public static BindableProperty SwipedRightCommandProperty;
public static BindableProperty SwipedLeftCommandProperty;

public Action<object> SwipedRight;
public Action<object> SwipedLeft;

public ICommand SwipedRightCommand { get; set; }
public ICommand SwipedLeftCommand { get; set; }

I am able to bind the ItemSource in my XAML content page but I can't seem to bind to the swipe left and swipe right commands.

XAML:

<swipecards:CardStackView
            x:Name="CardStackView"
            ItemsSource="{Binding MyList}"
            SwipedLeftCommand="{Binding SwipedLeft}"
            SwipedRightCommand="{Binding SwipedRight}"
            CardMoveDistance="60"
            Grid.Column="0" Grid.ColumnSpan="3"
            Grid.Row="0">

C# (in my view model)

public void SwipedLeft(object obj)
{
    System.Diagnostics.Debug.WriteLine("Something Happened");
}

public void SwipedRight(object obj)
{
    System.Diagnostics.Debug.WriteLine("Something Happened");
}

anyone know how to properly bind to the commands so my function is properly triggered?

Answer 1

Binding Command to classic Xamarin Button control looks like this:

XAML:

<Button Command="{Binding SwipeLeftCommand}" CommandParameter="{Binding SwipeLeftCommandParam}" />

ViewModel:

public ICommand SwipedRightCommand { get; } //getter is sufficient


public YourViewModel()
{
    //plain code (often comes with bad maintainability)
    SwipeLeftCommand = new Command(() => { /* code */ });

    //simple method attachment (with command parameter)
    SwipeLeftCommand = new Command((commandParameter) => SwipedLeft(commandParameter));

    //simple method + async/await call
    SwipeLeftCommand = new Command(async (commandParameter) => await SwipedLeft(commandParameter));
}