O2S.Components.PDFRender4NET 亲测有效，花了100分试出来的

引用using O2S.Components.PDFRender4NET; private void butPrint_Click(object sender, EventArgs e) { int isOK = 0; PDFFile file = PDFFile.Open(@"d:\XXX.pdf"); PrinterSettings settings = new PrinterSettings(); System.Drawing.Printing.PrintDocument pd = new System.Drawing.Printing.PrintDocument(); settings.PrintToFile = false; //设置纸张大小（可以不设置，取默认设置）3.90 in, 8.65 in //PaperSize ps = new PaperSize("test", 4, 9); PaperSize ps = new PaperSize(); ps.RawKind = 9; //如果是自定义纸张，就要大于118，（A4值为9，详细纸张类型与值的对照请看http://msdn.microsoft.com/zh-tw/library/system.drawing.printing.papersize.rawkind(v=vs.85).aspx） O2S.Components.PDFRender4NET.Printing.PDFPrintSettings pdfPrintSettings = new O2S.Components.PDFRender4NET.Printing.PDFPrintSettings(settings); //共多少页 file.PageCount //file.BeforePrintPage += new EventHandler<PrintPageEventArgs>(file_BeforePrintPage);//打印前做什么事 file.AfterPrintPage += new EventHandler<PrintPageEventArgs>(file_AfterPrint);//每页打印完后做什么事，比如输出还有X页需打印 pdfPrintSettings.PaperSize = ps; pdfPrintSettings.PageScaling = O2S.Components.PDFRender4NET.Printing.PageScaling.FitToPrinterMarginsProportional; pdfPrintSettings.PrinterSettings.Copies = 1; try { //settings.PrinterName = "hp LaserJet 1160 PCL 5e"; 不指定用默认打印机 //打印 file.Print(pdfPrintSettings); } catch (Exception ex) { MessageBox.Show(ex.Message); } finally { file.Dispose(); } MessageBox.Show("OK"); } private void file_AfterPrint(object sender, PrintPageEventArgs e) { //MessageBox.Show("当前打印成功!"); }