在android中打印现有的pdf文件
大家好，所以我试图在android上构建一个小样本打印应用程序，但似乎无法打印现有的pdf.关于使用画布创建自定义文档的文档很多，但是我已经有了该文档.基本上，我只是希望能够读取pdf文档并将其作为文件输出流直接发送到要打印的打印机.感谢您的帮助.
Hey everyone so I am trying to build a small sample printing app on android and can't seem to print an existing pdf. There is plenty of documentation on creating a custom document with the canvas but I already have the document. Basically I just want to be a able to read in a pdf document and send it as a file output stream directly to the printer to be printed. Any help is appreciated.
基本上，我只是希望能够读取pdf文档并将其作为文件输出流直接发送到要打印的打印机.
Basically I just want to be a able to read in a pdf document and send it as a file output stream directly to the printer to be printed.
这是严格不可能的，除非您找到某些提供此类API的Android专用打印机.
That's not strictly possible, unless you find some particular printer that offers such an API for Android.
如果您想使用Android打印框架，则需要创建一个可以处理现有PDF文件的PrintDocumentAdapter. 此示例项目演示了
If you wish to use the Android printing framework, you will need to create a PrintDocumentAdapter that can handle your existing PDF file. This sample project demonstrates one such PrintDocumentAdapter, though it is not general-purpose.