再谈Images到xps,pdf的转换

转换，实际上是将图片加入到xps,pdf文件中，不是真正意义的格式转换，在这篇blog中已经介绍了如何将图片转换为pdf。下面介绍图片到xps的转换，这里使用了.NET Framework3.0中的新功能，.NET 3.0中有对xps文件支持的类，xps也是OpenXML格式,
首先添加对.NET 3.0中的两个程集的引用ReachFramework，Windowbase,
转换代码代码如下:

protected bool Convert(string sourcePath, string targetPath)

{

Image img = Image.FromFile(sourcePath);

string resFile = sourcePath;

XpsDocument xpsDoc = new XpsDocument(targetPath, FileAccess.ReadWrite);

IXpsFixedDocumentSequenceWriter fds = xpsDoc.AddFixedDocumentSequence();

IXpsFixedDocumentWriter fd = fds.AddFixedDocument();

IXpsFixedPageWriter fp = fd.AddFixedPage();

XpsResource res = null;

XpsResource thumb = null;

res = fp.AddImage(XpsImageType.JpegImageType);

thumb = xpsDoc.AddThumbnail(XpsImageType.JpegImageType);

WriteStream(res.GetStream(), resFile);

WritePageContent(fp.XmlWriter, res, img.Width, img.Height);

res.Commit();

WriteStream(thumb.GetStream(), resFile);

thumb.Commit();

fp.Commit();

fd.Commit();

fds.Commit();

xpsDoc.Close();

return true;

}

private static void WritePageContent(System.Xml.XmlWriter xmlWriter, XpsResource res, int width, int height)

{

xmlWriter.WriteStartElement("FixedPage");

xmlWriter.WriteAttributeString("xmlns", @"http://schemas.microsoft.com/xps/2005/06");

xmlWriter.WriteAttributeString("Width", width.ToString());

xmlWriter.WriteAttributeString("Height", height.ToString());

xmlWriter.WriteAttributeString("xml:lang", "en-US");

xmlWriter.WriteStartElement("Canvas");

if (res is XpsImage)

{

xmlWriter.WriteStartElement("Path");

xmlWriter.WriteAttributeString("Data", "M 20,20 L 770,20 770,770 20,770 z");

xmlWriter.WriteStartElement("Path.Fill");

xmlWriter.WriteStartElement("ImageBrush");

xmlWriter.WriteAttributeString("ImageSource", res.Uri.ToString());

xmlWriter.WriteAttributeString("Viewbox", "0,0,750,750");

xmlWriter.WriteAttributeString("ViewboxUnits", "Absolute");

xmlWriter.WriteAttributeString("Viewport", "20,20,750,750");

xmlWriter.WriteAttributeString("ViewportUnits", "Absolute");

xmlWriter.WriteEndElement();

}

xmlWriter.WriteEndElement();

}

private static void WriteStream(Stream stream, string resFile)

{

using (FileStream sourceStream = new FileStream(resFile, FileMode.Open, FileAccess.Read))

{

byte[] buf = new byte[1024];

int read = 0;

while ((read = sourceStream.Read(buf, 0, buf.Length)) > 0)

{

stream.Write(buf, 0, read);

}

这样同一个图片得到的xps和pdf差异比较大，

当然，我们通过调整代码，也可以得到相近的效果，但需要时间，这里想到个折中的办法，Office 2007可以通过AddIn将文档转换为xps和pdf，通过它得到xps和pdf应该是一样的。所以，这里我们先将图片添加到一个word文档中，再通过office 2007得到xps和pdf，在上篇blog中的代码再添加将图片添加到word文档的代码：

wordDocument = wordApplication.Documents.Add(ref paramMissing, ref paramMissing, ref paramMissing, ref paramMissing);

wordDocument.InlineShapes.AddPicture(sourcePath, ref paramMissing, ref paramMissing, ref paramMissing);

object a = Path.GetTempPath() + Path.GetTempFileName() + ".docx";

object format = Word.WdSaveFormat.wdFormatDocumentDefault;

wordDocument.SaveAs(ref a, ref format,

ref paramMissing, ref paramMissing, ref paramMissing,

ref paramMissing, ref paramMissing);

添加了图片后的word文档先要保存到磁盘，然后，再转换为xps和pdf，否则会打开一个word窗口。这样我得到xps和pdf是一样的