我正在解析带有一些图像的HTML.
此图像存储为嵌入资源,而不是文件系统.
据我所知,我需要在HtmlPipelineContext中设置自定义图像提供程序,此提供程序需要检索图像路径或itextsharp图像.
问题是,有人知道我需要实现抽象图像提供程序的哪种方法?如何?
这是我的代码:
var list = new List<string> { text };
byte[] renderedBuffer;
using (var outputMemoryStream = new MemoryStream())
{
using (
var pdfDocument = new Document(PageSize.A4, 30, 30, 30, 30))
{
var pdfWriter = PdfWriter.GetInstance(pdfDocument, outputMemoryStream);
pdfWriter.CloseStream = false;
pdfDocument.Open();
HtmlPipelineContext htmlContext = new HtmlPipelineContext(new CssAppliersImpl());
htmlContext.SetImageProvider(new MyImageProvider());
htmlContext.SetTagFactory(Tags.GetHtmlTagProcessorFactory());
ICSSResolver cssResolver = XMLWorkerHelper.GetInstance().GetDefaultCssResolver(true);
CssResolverPipeline pipeline = new CssResolverPipeline(cssResolver, new HtmlPipeline(htmlContext, new PdfWriterPipeline(pdfDocument, pdfWriter)));
XMLWorker worker = new XMLWorker(pipeline, true);
XMLParser p = new XMLParser(worker);
foreach (var htmlText in list)
{
using (var htmlViewReader = new StringReader(htmlText))
{
p.Parse(htmlViewReader);
}
}
}
renderedBuffer = new byte[outputMemoryStream.Position];
outputMemoryStream.Position = 0;
outputMemoryStream.Read(renderedBuffer, 0, renderedBuffer.Length);
}
提前致谢.
解决方法:
使用自定义图像提供程序似乎不支持它.它唯一真正支持的是改变根路径.
但是,这是问题的一个解决方案:
创建一个名为< resimg src =“{resource name}”/>的新html标记,并为其编写自定义标记处理器.
这是实施:
/// <summary>
/// Our custom HTML Tag to add an IElement.
/// </summary>
public class ResourceImageHtmlTagProcessor : AbstractTagProcessor
{
public override IList<IElement> End(IWorkerContext ctx, Tag tag, IList<IElement> currentContent)
{
var src = tag.Attributes["src"];
var bitmap = (Bitmap)Resources.ResourceManager.GetObject(src);
if (bitmap == null)
throw new RuntimeWorkerException("No resource with the name: " + src);
var converter = new ImageConverter();
var image = Image.GetInstance((byte[])converter.ConvertTo(bitmap, typeof(byte[])));
HtmlPipelineContext htmlPipelineContext = this.GetHtmlPipelineContext(ctx);
return new List<IElement>(1)
{
this.GetCssAppliers().Apply(
new Chunk((Image)this.GetCssAppliers().Apply(image, tag, htmlPipelineContext), 0f, 0f, true),
tag,
htmlPipelineContext)
};
}
}
要配置新处理器,请使用以下命令替换指定TagFactory的行:
var tagProcessorFactory = Tags.GetHtmlTagProcessorFactory();
tagProcessorFactory.AddProcessor(new ResourceImageHtmlTagProcessor(), new[] { "resimg" });
htmlContext.SetTagFactory(tagProcessorFactory);