зеркало из https://github.com/DeGsoft/maui-linux.git
229 строки
6.5 KiB
C#
229 строки
6.5 KiB
C#
using System;
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using System.Drawing;
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using System.ComponentModel;
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using System.IO;
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using System.Threading;
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using System.Threading.Tasks;
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using Foundation;
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using UIKit;
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using Xamarin.Forms.Internals;
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using RectangleF = CoreGraphics.CGRect;
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using System.Linq;
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namespace Xamarin.Forms.Platform.iOS
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{
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public static class ImageExtensions
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{
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public static UIViewContentMode ToUIViewContentMode(this Aspect aspect)
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{
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switch (aspect)
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{
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case Aspect.AspectFill:
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return UIViewContentMode.ScaleAspectFill;
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case Aspect.Fill:
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return UIViewContentMode.ScaleToFill;
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case Aspect.AspectFit:
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default:
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return UIViewContentMode.ScaleAspectFit;
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}
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}
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}
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public class ImageRenderer : ViewRenderer<Image, UIImageView>, IImageVisualElementRenderer
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{
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bool _isDisposed;
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public ImageRenderer() : base()
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{
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ImageElementManager.Init(this);
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}
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protected override void Dispose(bool disposing)
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{
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if (_isDisposed)
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return;
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if (disposing)
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{
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UIImage oldUIImage;
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if (Control != null && (oldUIImage = Control.Image) != null)
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{
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ImageElementManager.Dispose(this);
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oldUIImage.Dispose();
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}
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}
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_isDisposed = true;
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base.Dispose(disposing);
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}
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protected override async void OnElementChanged(ElementChangedEventArgs<Image> e)
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{
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if (Control == null)
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{
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var imageView = new UIImageView(RectangleF.Empty);
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imageView.ContentMode = UIViewContentMode.ScaleAspectFit;
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imageView.ClipsToBounds = true;
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SetNativeControl(imageView);
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}
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if (e.NewElement != null)
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{
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await TrySetImage(e.OldElement as Image);
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}
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base.OnElementChanged(e);
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}
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protected override async void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
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{
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base.OnElementPropertyChanged(sender, e);
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if (e.PropertyName == Image.SourceProperty.PropertyName)
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await TrySetImage().ConfigureAwait(false);
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}
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protected virtual async Task TrySetImage(Image previous = null)
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{
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// By default we'll just catch and log any exceptions thrown by SetImage so they don't bring down
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// the application; a custom renderer can override this method and handle exceptions from
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// SetImage differently if it wants to
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try
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{
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await SetImage(previous).ConfigureAwait(false);
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}
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catch (Exception ex)
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{
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Log.Warning(nameof(ImageRenderer), "Error loading image: {0}", ex);
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}
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finally
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{
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((IImageController)Element)?.SetIsLoading(false);
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}
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}
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protected async Task SetImage(Image oldElement = null)
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{
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await ImageElementManager.SetImage(this, Element, oldElement).ConfigureAwait(false);
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}
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void IImageVisualElementRenderer.SetImage(UIImage image) => Control.Image = image;
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bool IImageVisualElementRenderer.IsDisposed => _isDisposed;
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UIImageView IImageVisualElementRenderer.GetImage() => Control;
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}
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public interface IImageSourceHandler : IRegisterable
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{
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Task<UIImage> LoadImageAsync(ImageSource imagesource, CancellationToken cancelationToken = default(CancellationToken), float scale = 1);
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}
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public sealed class FileImageSourceHandler : IImageSourceHandler
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{
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public Task<UIImage> LoadImageAsync(ImageSource imagesource, CancellationToken cancelationToken = default(CancellationToken), float scale = 1f)
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{
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UIImage image = null;
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var filesource = imagesource as FileImageSource;
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var file = filesource?.File;
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if (!string.IsNullOrEmpty(file))
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image = File.Exists(file) ? new UIImage(file) : UIImage.FromBundle(file);
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if (image == null)
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{
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Log.Warning(nameof(FileImageSourceHandler), "Could not find image: {0}", imagesource);
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}
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return Task.FromResult(image);
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}
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}
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public sealed class StreamImagesourceHandler : IImageSourceHandler
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{
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public async Task<UIImage> LoadImageAsync(ImageSource imagesource, CancellationToken cancelationToken = default(CancellationToken), float scale = 1f)
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{
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UIImage image = null;
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var streamsource = imagesource as StreamImageSource;
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if (streamsource?.Stream != null)
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{
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using (var streamImage = await ((IStreamImageSource)streamsource).GetStreamAsync(cancelationToken).ConfigureAwait(false))
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{
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if (streamImage != null)
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image = UIImage.LoadFromData(NSData.FromStream(streamImage), scale);
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}
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}
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if (image == null)
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{
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Log.Warning(nameof(StreamImagesourceHandler), "Could not load image: {0}", streamsource);
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}
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return image;
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}
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}
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public sealed class ImageLoaderSourceHandler : IImageSourceHandler
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{
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public async Task<UIImage> LoadImageAsync(ImageSource imagesource, CancellationToken cancelationToken = default(CancellationToken), float scale = 1f)
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{
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UIImage image = null;
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var imageLoader = imagesource as UriImageSource;
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if (imageLoader?.Uri != null)
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{
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using (var streamImage = await imageLoader.GetStreamAsync(cancelationToken).ConfigureAwait(false))
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{
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if (streamImage != null)
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image = UIImage.LoadFromData(NSData.FromStream(streamImage), scale);
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}
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}
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if (image == null)
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{
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Log.Warning(nameof(ImageLoaderSourceHandler), "Could not load image: {0}", imageLoader);
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}
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return image;
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}
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}
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public sealed class FontImageSourceHandler : IImageSourceHandler
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{
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public Task<UIImage> LoadImageAsync(
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ImageSource imagesource,
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CancellationToken cancelationToken = default(CancellationToken),
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float scale = 1f)
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{
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UIImage image = null;
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var fontsource = imagesource as FontImageSource;
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if (fontsource != null)
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{
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var iconcolor = fontsource.Color != Color.Default ? fontsource.Color : Color.White;
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var imagesize = new SizeF((float)fontsource.Size, (float)fontsource.Size);
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var hasFontFamily = fontsource.FontFamily != null && UIFont.FamilyNames.Contains(fontsource.FontFamily);
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var font = hasFontFamily ?
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UIFont.FromName(fontsource.FontFamily, (float)fontsource.Size) :
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UIFont.SystemFontOfSize((float)fontsource.Size);
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UIGraphics.BeginImageContextWithOptions(imagesize, false, 0f);
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var attString = new NSAttributedString(fontsource.Glyph, font: font, foregroundColor: iconcolor.ToUIColor());
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var ctx = new NSStringDrawingContext();
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var boundingRect = attString.GetBoundingRect(imagesize, (NSStringDrawingOptions)0, ctx);
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attString.DrawString(new RectangleF(
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imagesize.Width / 2 - boundingRect.Size.Width / 2,
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imagesize.Height / 2 - boundingRect.Size.Height / 2,
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imagesize.Width,
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imagesize.Height));
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image = UIGraphics.GetImageFromCurrentImageContext();
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UIGraphics.EndImageContext();
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if (iconcolor != Color.Default)
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image = image.ImageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
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}
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return Task.FromResult(image);
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}
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}
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} |