如何在 MAUI 中将 SVG 转换为 PNG

Question

我正在尝试使用 MAUI 应用程序中的 Aspose.Imaging 包将 svg 图像从 url 转换为 png 格式。

但是我在 SvgImage image = (SvgImage)Image.Load(localPath); 处遇到以下错误

{Aspose.Imaging.CoreExceptions.ImageLoadException: Image loading failed.
 ---> System.TypeInitializationException: The type initializer for 'Aspose.Imaging.ImageExportersRegistry' threw an exception.
 ---> Aspose.Imaging.CoreExceptions.ImageLoadException: Error invocation Aspose.Imaging.InjectExporters.Process
 ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.ArgumentException: Font 'FreeSans' cannot be found
   at System.Drawing.FontFamily.(String , FontCollection )
   at System.Drawing.FontFamily..ctor(String name)
   at System.Drawing.Font.(String , Single , FontStyle , GraphicsUnit , Byte , Boolean )
  

以下是我的代码：

string imageUrl = "https://dev.w3.org/SVG/tools/svgweb/samples/svg-files/dst.svg";
            using var httpResponse = await Client.GetAsync(imageUrl).ConfigureAwait(false);

            if (httpResponse.StatusCode is HttpStatusCode.OK)
            {
                var downloadedImage = await httpResponse.Content.ReadAsByteArrayAsync().ConfigureAwait(false);

                var downloadedImageModel = new DownloadedImageModel
                {
                    ImageUrl = imageUrl,
                    DownloadedImageBlob = downloadedImage
                };
Uri myUri = new Uri(imageUrl, UriKind.Absolute);
                //// Load the image
                string documentsPath = Android.OS.Environment.GetExternalStoragePublicDirectory(Android.OS.Environment.DirectoryPictures).AbsolutePath;
                string localFilename = "dst.svg";
                string localPath = System.IO.Path.Combine(documentsPath, localFilename);
                File.WriteAllBytes(localPath, downloadedImageModel.DownloadedImageBlob);
                try
                {
                    SvgImage image = (SvgImage)Image.Load(localPath);
                    using (image)
                    {
                        // Create an instance of PNG options and Save the results to disk
                        PngOptions pngOptions = new PngOptions();

                        SvgRasterizationOptions svgOptions = new SvgRasterizationOptions();

                        svgOptions.PageWidth = 100;
                        svgOptions.PageHeight = 200;

                        pngOptions.VectorRasterizationOptions = svgOptions;
                        //image.Save(dataDir + "result.png", pngOptions);
                    }
                }
}

如有任何帮助，我们将不胜感激！

Answer 1

在使用Image.Load之前，需要调用FontSettings.SetFontFolders()