I cant refresh my listview with new data in my UI when I change something. I'm using MVVM

SpontonLuciano

I got a TabbedPage, this contain two pages (Products - ShoppingCart). To both of them I shared in their constructor the same instant of my viewmodel. In my fisrt page a want to search some products and add it to my second page (my shopping cart) every time I chose a product from the first page I add it on a "list" and I want that the second page could read that list and refresh the UI with the items of the list and if I add the same product I will check on the list and if it exist I'll change the count and all of that I need to reflect it in the second page when that process finish.

matrixlukan

Define your **CartItem **class as follows.
public class CartItem
{
public Product Item {get;set;}
public int ItemCount {get;set;} = 1;
}

Now change AddItemToCart() as follows:
public void AddItemToCart(Product newProduct)
{
var cartItems = Cart.ToList();
if(cartItems.Exists(x=>x.Id == newProduct.Id))
{
cartItems.FirstOrDefault(x=>x.Id == newProduct.Id).ItemCount ++;
}
else
{
cartItems.Add(newItem);
}

Cart = new ObservableCollection<CartItems>(cartItems);
OnPropertyChanged(Cart);

}

If this solves your issue then hit a like.

matrixlukan

    public ObservableCollection<CartItems> Cart {get; set; } = new  ObservableCollection<CartItems>();
    ....
    ....

    public void AddItemToCart(CartItem newItem)
    {
        var cartItems = Cart.ToList();
        cartItems.Add(newItem);
        Cart = new ObservableCollection<CartItems>(cartItems);
        OnPropertyChanged(Cart);
    }

I hope this solves your problem.

SpontonLuciano

@matrixlukan Thats worked to add an item! How can I change the "count" property of a product which is already on the list and then show it again with the new count on the UI?

ColeX

Make your Product class implement INotifyPropertyChanged , create binding between Count and Label.Text , notify the UI while Count property changes .

 public class Product : INotifyPropertyChanged
 {
    private int count;
    // Declare the event
    public event PropertyChangedEventHandler PropertyChanged;

    public Product()
    {
    }

    public string Count
    {
        get { return count; }
        set
        {
            count = value;
            // Call OnPropertyChanged whenever the property is updated
            OnPropertyChanged("Count");
        }
    }

    // Create the OnPropertyChanged method to raise the event
    protected void OnPropertyChanged(string name)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(name));
        }
    }
}

matrixlukan

Define your **CartItem **class as follows.
public class CartItem
{
public Product Item {get;set;}
public int ItemCount {get;set;} = 1;
}

Now change AddItemToCart() as follows:
public void AddItemToCart(Product newProduct)
{
var cartItems = Cart.ToList();
if(cartItems.Exists(x=>x.Id == newProduct.Id))
{
cartItems.FirstOrDefault(x=>x.Id == newProduct.Id).ItemCount ++;
}
else
{
cartItems.Add(newItem);
}

Cart = new ObservableCollection<CartItems>(cartItems);
OnPropertyChanged(Cart);

}

If this solves your issue then hit a like.

SpontonLuciano

@matrixlukan Thanks!!