Xamarin形式：为什么细胞之间存在间隙

Question

我在右边的项目旁边有一个自定义视图，以黑色突出显示。

由于黑色自定义视图，每个视图单元格都有很大的间隙。此黑色视图是在bindingContextChanged函数中添加的网格。

public partial class ShiftTemplate : ViewCell
{
    public ShiftTemplate()
    {
        InitializeComponent();
    }
}

public class ShiftView : ContentView
{  
    protected override void OnBindingContextChanged()
    {
        base.OnBindingContextChanged();

        var model = BindingContext as StaffShiftViewModel;
        var grid = new Grid(); 

        var shiftCount = 0;
        var index = 0;

        grid.ColumnDefinitions.Add(new ColumnDefinition() { Width = GridLength.Star });
        grid.ColumnDefinitions.Add(new ColumnDefinition() { Width = GridLength.Star });

        foreach (var shift in model.Shifts)
        {
            grid.RowDefinitions.Add(new RowDefinition() { Height = GridLength.Auto });
            grid.RowDefinitions.Add(new RowDefinition() { Height = GridLength.Auto });
            grid.RowDefinitions.Add(new RowDefinition() { Height = GridLength.Auto });

            var timeLabel = new Label
            {
                Text = shift.Time,
                VerticalTextAlignment = TextAlignment.Center,
                HorizontalTextAlignment = TextAlignment.End
            };

            var clockButton = new Button
            {
                Text = shift.ClockStatus,
                VerticalOptions = LayoutOptions.Center,
                HorizontalOptions = LayoutOptions.Start,
                Command = shift.OnClockingPopupCommand                             
            };

            var binding = new Binding();
            binding.Source = shift;
            binding.Path = nameof(shift.ClockStatus);
            binding.Mode = BindingMode.OneWay;

            clockButton.SetBinding(Button.TextProperty, binding);

            var line = new BoxView { HorizontalOptions = LayoutOptions.FillAndExpand, VerticalOptions = LayoutOptions.Center, HeightRequest = 1, BackgroundColor = Color.Gray };

            grid.Children.Add(timeLabel, 0, 1, shiftCount, shiftCount+1);
            grid.Children.Add(clockButton, 1, 2, shiftCount, shiftCount+1);


            index += 1;

            if (index < model.Shifts.Count)
                grid.Children.Add(line, 0, 2, shiftCount + 1, shiftCount + 2);

            shiftCount+=2;
        }

        Content = grid;
        ForceLayout();
    }
}