Question

我在互联网上搜索了很多但似乎Google没有答案..

那么如何从我的UWP项目部分访问嵌入式图像（在PCL部分中）？

Answer 1

您可以使用Assembly.GetCallingAssembly()从“本机”平台程序集访问基于PCL的程序集，从而访问其嵌入资源。

实施例

依赖接口：

public interface IResource
{
    bool CheckEmbeddedAccess(string imageName);
}

平台实施：

public bool CheckEmbeddedAccess(string imageName)
{
    var callingAssembly = Assembly.GetCallingAssembly();
    System.IO.Stream file = callingAssembly.GetManifestResourceStream(imageName);
    if (file != null)
    {
        // do something with stream 
        return true;
    }
    return false;
}

PCL的用法：

var exists = DependencyService.Get<IResource>().CheckEmbeddedAccess("ImageResource.Face.png");

注意：确保使用正确的“资源ID”，因为默认情况下，当您将资源添加到项目时，资源会附加程序集名称（点表示法）。要查看所有实际资源ID，请在依赖服务实现中使用它来迭代它们：

foreach (string resourceName in callingAssembly.GetManifestResourceNames())
{
    Console.WriteLine(resourceName);
}

Answer 2

感谢@SushiHangover！

我正在处理嵌入式图片，但由于它是渲染器，因此我将a and not b放入我的对象中。 Si我确实喜欢它并最终有效：）

SourcePath

然后我用这部分

处理它

using ImageCircleProject.CustomControl;
using ImageCircleProject.UWP.CustomRenderer;
using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Windows.ApplicationModel;
using Windows.Storage;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Imaging;
using Windows.UI.Xaml.Shapes;
using Xamarin.Forms;
using Xamarin.Forms.Platform.UWP;

[assembly: ExportRenderer(typeof(CustomImageCircle), typeof(CustomImageCircleRenderer))]
namespace ImageCircleProject.UWP.CustomRenderer
{
public class CustomImageCircleRenderer : ViewRenderer<CustomImageCircle, Ellipse>
{
    private CustomImageCircle customImageCircle;

    protected override void OnElementChanged(ElementChangedEventArgs<CustomImageCircle> e)
    {
        base.OnElementChanged(e);

        if (e.OldElement != null)
        {

        }

        if (e.NewElement != null)
        {
            customImageCircle = e.NewElement as CustomImageCircle;

            Ellipse ellipse = new Ellipse();
            SetNativeControl(ellipse);
        }
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected async override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
    {
        base.OnElementPropertyChanged(sender, e);

        if (Control != null)
        {
            var min = Math.Min(Element.Width, Element.Height) / 2.0f;
            if (min <= 0)
                return;

            double radius;
            if (Element.Width < Element.Height)
            {
                radius = Element.Width;
            }
            else
            {
                radius = Element.Height;
            }

            Control.Width = radius;
            Control.Height = radius;

            // That will be our fallback fill if can't make sense of the ImageSource.
            Control.Fill = new SolidColorBrush(Windows.UI.Color.FromArgb(255, 52, 152, 219));

            BitmapImage bitmapImage = null;

            // Handle file images
            if (Element.Source is FileImageSource)
            {
                FileImageSource fi = Element.Source as FileImageSource;
                string myFile = System.IO.Path.Combine(Package.Current.InstalledLocation.Path, fi.File);
                StorageFolder myFolder = await StorageFolder.GetFolderFromPathAsync(System.IO.Path.GetDirectoryName(myFile));

                using (Stream s = await myFolder.OpenStreamForReadAsync(System.IO.Path.GetFileName(myFile)))
                {
                    var memStream = new MemoryStream();
                    await s.CopyToAsync(memStream);
                    memStream.Position = 0;
                    bitmapImage = new BitmapImage();
                    bitmapImage.SetSource(memStream.AsRandomAccessStream());
                }

            }
            // handle embedded images
            else if (Element.Source is StreamImageSource)
            {
                using (Stream s = await GetStreamFromImageSourceAsync(Element.Source as StreamImageSource))
                {
                    var memStream = new MemoryStream();
                    await s.CopyToAsync(memStream);
                    memStream.Position = 0;
                    bitmapImage = new BitmapImage();
                    bitmapImage.SetSource(memStream.AsRandomAccessStream());
                }
            }
            // Handle uri images
            else if (Element.Source is UriImageSource)
            {
                bitmapImage = new BitmapImage((Element.Source as UriImageSource).Uri);
            }

            if (bitmapImage != null)
                Control.Fill = new ImageBrush() { ImageSource = bitmapImage };
        }
    }

    private static async Task<Stream> GetStreamFromImageSourceAsync(StreamImageSource imageSource, CancellationToken cancellationToken = default(CancellationToken))
    {
        if (imageSource.Stream != null)
        {
            return await imageSource.Stream(cancellationToken);
        }
        return null;
    }
}
}

因为// handle embedded images else if (Element.Source is StreamImageSource) { using (Stream s = await GetStreamFromImageSourceAsync(Element.Source as StreamImageSource)) { var memStream = new MemoryStream(); await s.CopyToAsync(memStream); memStream.Position = 0; bitmapImage = new BitmapImage(); bitmapImage.SetSource(memStream.AsRandomAccessStream()); } }已经存在，我用它来重新创建图像

Xamarin表单 - 从UWP自定义ImageRenderer访问嵌入式映像

2 个答案:

实施例