Is it possible to write some logic for a viewcell and get a value from this this viewcell field?

Question

Is it possible to create a ListView with ViewCells that will contain two Buttons and Label, first button will be "+", second "-" and a label will be a counter that will show how much "+" button has been tapped.

Then I want to be able to get from my listview an item that is binded to this viewcell and information about how much this item has been selected.

For now I created a StackLayout filled with Views thats "mocks" a Viewcells. This solution is so bad for many items because I have to create lots of Views (it takes few seconds).

So I would like to solve the problem using a ListView but I have no idea how to achive this. Or maybe you have a better solution than using a listview?

Answer 1

this should be trivial. First, create a data structure to hold your data

public class MyData : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;  

    private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")  
    {  
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    } 

  private double _count;
  public double Count 
  { 
    get
    { return _count; }
    set
    { 
      _count = value;
      NotifyPropertyChanged();
    }
}

List<MyData> data { get; set; }

you will need to initialize it with as many rows as your want to display in your list. The create a template with a Label and Buttons that are bound to your Count property

<ListView x:Name="listView" >
  <ListView.ItemTemplate>
    <DataTemplate>
      <ViewCell>
        <StackLayout>
          <Label Text="{Binding Count}" />
          <Button Clicked="Increment" CommandParameter="{Binding .}" Text="+" />
          <Button Clicked="Decrement" CommandParameter="{Binding .}" Text="-" />            
        </StackLayout>
      </ViewCell>
    </DataTemplate>
  </ListView.ItemTemplate>
</ListView>

in your code-behind

protected void Decrement(object sender, EventArgs args) {
  var b = (Button)sender;
  var data = (MyData)b.CommandParameter;
  data.Count--;
}

protected void Increment(object sender, EventArgs args) {
  var b = (Button)sender;
  var data = (MyData)b.CommandParameter;
  data.Count++;
}

finally, use binding or direct assignment to set the List's ItemsSourcee

listView.ItemsSource = data;