我在使用podofo修改pdf文档时遇到了问题，如果你有时间，请帮我解决！
我在http://podofo.sourceforge.net/download.html上找到了podofo源码，在windows 7 x86上编译，发现podofo的功能非常强大。
但是当我在示例“helloworld.cpp”中更改某些内容时，只需更改一点代码即可修改pdf文档并以其他文件名保存！
当我将本地pdf文档文件（本地pdf文档是从使用office word 2007上的windows COM接口的Word文档中保存的）传入函数时，新文件输出成功，但输出文本垂直翻转，输出文本的Y pos 垂直翻转。
（有些人说nn这种情况你必须处理现有内容可能已经改变了图形状态的事实，例如改变了当前的变换矩阵，也许他是对的，但我找不到改变图形的函数状态并改变了当前的变换矩阵）
这是图片截图，不知道为什么输出的文字是垂直翻转的：
奇怪的是，当我通过示例“helloworld”创建的文档“output.pdf”时它运行良好。
如果您有时间，请帮我解决，非常感谢！
我更改的代码如下所示：
#define MEMDOCUMENT 1 // macro switch
void HelloWorld( const char* pszFilename )
{
/*
* PdfStreamedDocument is the class that can actually write a PDF file.
* PdfStreamedDocument is much faster than PdfDocument, but it is only
* suitable for creating/drawing PDF files and cannot modify existing
* PDF documents.
*
* The document is written directly to pszFilename while being created.
*/
#if MEMDOCUMENT
PdfMemDocument document( pszFilename ); //open local pdf documet
#else
PdfStreamedDocument document( pszFilename ); //create a new pdf documet
#endif
/*
* PdfPainter is the class which is able to draw text and graphics
* directly on a PdfPage object.
*/
PdfPainter painter;
/*
* This pointer will hold the page object later.
* PdfSimpleWriter can write several PdfPage's to a PDF file.
*/
PdfPage* pPage;
/*
* A PdfFont object is required to draw text on a PdfPage using a PdfPainter.
* PoDoFo will find the font using fontconfig on your system and embedd truetype
* fonts automatically in the PDF file.
*/
PdfFont* pFont;
try {
/*
* The PdfDocument object can be used to create new PdfPage objects.
* The PdfPage object is owned by the PdfDocument will also be deleted automatically
* by the PdfDocument object.
*
* You have to pass only one argument, i.e. the page size of the page to create.
* There are predefined enums for some common page sizes.
*/
#if MEMDOCUMENT
pPage = document.GetPage(0); //get the first page and modify it
#else
pPage = document.CreatePage( PdfPage::CreateStandardPageSize( ePdfPageSize_A4 ) );
#endif
/*
* If the page cannot be created because of an error (e.g. ePdfError_OutOfMemory )
* a NULL pointer is returned.
* We check for a NULL pointer here and throw an exception using the RAISE_ERROR macro.
* The raise error macro initializes a PdfError object with a given error code and
* the location in the file in which the error ocurred and throws it as an exception.
*/
if( !pPage )
{
PODOFO_RAISE_ERROR( ePdfError_InvalidHandle );
}
/*
* Set the page as drawing target for the PdfPainter.
* Before the painter can draw, a page has to be set first.
*/
painter.SetPage( pPage );
/*
* Create a PdfFont object using the font "Arial".
* The font is found on the system using fontconfig and embedded into the
* PDF file. If Arial is not available, a default font will be used.
*
* The created PdfFont will be deleted by the PdfDocument.
*/
pFont = document.CreateFont( "Arial" );
/*
* If the PdfFont object cannot be allocated return an error.
*/
if( !pFont )
{
PODOFO_RAISE_ERROR( ePdfError_InvalidHandle );
}
/*
* Set the font size
*/
pFont->SetFontSize( 18.0 );
/*
* Set the font as default font for drawing.
* A font has to be set before you can draw text on
* a PdfPainter.
*/
painter.SetFont( pFont );
/*
* You could set a different color than black to draw
* the text.
*
* SAFE_OP( painter.SetColor( 1.0, 0.0, 0.0 ) );
*/
/*
* Actually draw the line "Hello World!" on to the PdfPage at
* the position 2cm,2cm from the top left corner.
* Please remember that PDF files have their origin at the
* bottom left corner. Therefore we substract the y coordinate
* from the page height.
*
* The position specifies the start of the baseline of the text.
*
* All coordinates in PoDoFo are in PDF units.
* You can also use PdfPainterMM which takes coordinates in 1/1000th mm.
*
*/
painter.SetTransformationMatrix(1,0,0,-1,0,pPage->GetPageSize().GetHeight());
painter.DrawText( 56.69, pPage->GetPageSize().GetHeight() - 56.69, "Hello World!" );
painter.DrawText( 56.69, pPage->GetPageSize().GetHeight() - 96.69, "Hello World!" );
/*
* Tell PoDoFo that the page has been drawn completely.
* This required to optimize drawing operations inside in PoDoFo
* and has to be done whenever you are done with drawing a page.
*/
painter.FinishPage();
/*
* Set some additional information on the PDF file.
*/
document.GetInfo()->SetCreator ( PdfString("examplahelloworld - A PoDoFo test application") );
document.GetInfo()->SetAuthor ( PdfString("Dominik Seichter") );
document.GetInfo()->SetTitle ( PdfString("Hello World") );
document.GetInfo()->SetSubject ( PdfString("Testing the PoDoFo PDF Library") );
document.GetInfo()->SetKeywords( PdfString("Test;PDF;Hello World;") );
/*
* The last step is to close the document.
*/
#if MEMDOCUMENT
document.Write("outputex.pdf"); //save page change
#else
document.Close();
#endif
} catch ( const PdfError & e ) {
/*
* All PoDoFo methods may throw exceptions
* make sure that painter.FinishPage() is called
* or who will get an assert in its destructor
*/
try {
painter.FinishPage();
} catch( ... ) {
/*
* Ignore errors this time
*/
}
throw e;
}
}