maui-linux/Xamarin.Forms.Platform.UAP/ViewToRendererConverter.cs

102 строки
2.8 KiB
C#

using System;
using Windows.Foundation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
namespace Xamarin.Forms.Platform.UWP
{
public class ViewToRendererConverter : Windows.UI.Xaml.Data.IValueConverter
{
public object Convert(object value, Type targetType, object parameter, string language)
{
var view = value as View;
if (view == null)
{
var page = value as Page;
if (page != null)
{
IVisualElementRenderer renderer = page.GetOrCreateRenderer();
return renderer.ContainerElement;
}
}
if (view == null)
return null;
return new WrapperControl(view);
}
public object ConvertBack(object value, Type targetType, object parameter, string language)
{
throw new NotSupportedException();
}
class WrapperControl : Panel
{
readonly View _view;
FrameworkElement FrameworkElement { get; }
public WrapperControl(View view)
{
_view = view;
_view.MeasureInvalidated += (sender, args) => { InvalidateMeasure(); };
IVisualElementRenderer renderer = Platform.CreateRenderer(view);
Platform.SetRenderer(view, renderer);
FrameworkElement = renderer.ContainerElement;
Children.Add(renderer.ContainerElement);
// make sure we re-measure once the template is applied
if (FrameworkElement != null)
{
FrameworkElement.Loaded += (sender, args) =>
{
// If the view is a layout (stacklayout, grid, etc) we need to trigger a layout pass
// with all the controls in a consistent native state (i.e., loaded) so they'll actually
// have Bounds set
(_view as Layout)?.ForceLayout();
InvalidateMeasure();
};
}
}
protected override Windows.Foundation.Size ArrangeOverride(Windows.Foundation.Size finalSize)
{
_view.IsInNativeLayout = true;
Layout.LayoutChildIntoBoundingRegion(_view, new Rectangle(0, 0, finalSize.Width, finalSize.Height));
_view.IsInNativeLayout = false;
FrameworkElement?.Arrange(new Rect(_view.X, _view.Y, _view.Width, _view.Height));
return finalSize;
}
protected override Windows.Foundation.Size MeasureOverride(Windows.Foundation.Size availableSize)
{
Size request = _view.Measure(availableSize.Width, availableSize.Height, MeasureFlags.IncludeMargins).Request;
if (request.Height < 0)
{
request.Height = availableSize.Height;
}
Windows.Foundation.Size result;
if (_view.HorizontalOptions.Alignment == LayoutAlignment.Fill && !double.IsInfinity(availableSize.Width) && availableSize.Width != 0)
{
result = new Windows.Foundation.Size(availableSize.Width, request.Height);
}
else
{
result = new Windows.Foundation.Size(request.Width, request.Height);
}
_view.Layout(new Rectangle(0, 0, result.Width, result.Height));
FrameworkElement?.Measure(availableSize);
return result;
}
}
}
}