要将背景颜色应用于列表视图所选项目,请按照下列步骤操作:
制作自定义控件:
using Xamarin.Forms;
namespace xamformsdemo.CustomControls
{
public class ExtendedViewCell : ViewCell
{
public static readonly BindableProperty SelectedBackgroundColorProperty =
BindableProperty.Create("SelectedBackgroundColor",
typeof(Color),
typeof(ExtendedViewCell),
Color.Default);
public Color SelectedBackgroundColor
{
get { return (Color)GetValue(SelectedBackgroundColorProperty); }
set { SetValue(SelectedBackgroundColorProperty, value); }
}
}
}
安卓渲染器:
[assembly: ExportRenderer(typeof(ExtendedViewCell), typeof(ExtendedViewCellRenderer))]
namespace xamformsdemo.Droid.CustomRenderers
{
public class ExtendedViewCellRenderer : ViewCellRenderer
{
private Android.Views.View _cellCore;
private Drawable _unselectedBackground;
private bool _selected;
protected override Android.Views.View GetCellCore(Cell item,
Android.Views.View convertView,
ViewGroup parent,
Context context)
{
_cellCore = base.GetCellCore(item, convertView, parent, context);
_selected = false;
_unselectedBackground = _cellCore.Background;
return _cellCore;
}
protected override void OnCellPropertyChanged(object sender, PropertyChangedEventArgs args)
{
base.OnCellPropertyChanged(sender, args);
if (args.PropertyName == "IsSelected")
{
_selected = !_selected;
if (_selected)
{
var extendedViewCell = sender as ExtendedViewCell;
_cellCore.SetBackgroundColor(extendedViewCell.SelectedBackgroundColor.ToAndroid());
}
else
{
_cellCore.SetBackground(_unselectedBackground);
}
}
}
}
}
iOS 渲染器:
[assembly: ExportRenderer(typeof(ExtendedViewCell), typeof(ExtendedViewCellRenderer))]
namespace xamformsdemo.iOS.CustomRenderers
{
public class ExtendedViewCellRenderer : ViewCellRenderer
{
public override UITableViewCell GetCell(Cell item, UITableViewCell reusableCell, UITableView tv)
{
var cell = base.GetCell(item, reusableCell, tv);
var view = item as ExtendedViewCell;
cell.SelectedBackgroundView = new UIView
{
BackgroundColor = view.SelectedBackgroundColor.ToUIColor(),
};
return cell;
}
}
}
在 XAML 中使用:
<ListView.ItemTemplate>
<DataTemplate>
<customControls:ExtendedViewCell SelectedBackgroundColor="Teal">
<ViewCell.View>
<StackLayout HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand" Orientation="Vertical"
Padding="4" Spacing="8">
<Label TextColor="White" Text="{Binding .ItemName}"/>
<Label TextColor="Yellow" Text="{Binding .LastUpdated, StringFormat='Last seen: {0:HH:mm:ss}'}"/>
</StackLayout>
</ViewCell.View>
</customControls:ExtendedViewCell>
</DataTemplate>
</ListView.ItemTemplate>
您可以参考下面的链接来解决问题:https://blog.wislon.io/posts/2017/04/11/xamforms-listview-selected-colour