printing - JavaFX8 打印 API : how to set correctly the Printable area

Question

在我的 javafx 应用程序中，我使用 JavaFX 8 打印 API 来打印节点，尽管我已经用 A4 纸设置了 pageLayout，但我遇到了打印区域的问题......这是我的代码:

public static  void printNode(final Node node) throws NoSuchMethodException, InstantiationException, IllegalAccessException, InvocationTargetException {
        Printer printer = Printer.getDefaultPrinter();   
        PageLayout pageLayout = printer.createPageLayout(Paper.A4, PageOrientation.PORTRAIT, 0,0,0,0 );      
        PrinterJob job = PrinterJob.createPrinterJob();
        if (job != null  && job.showPrintDialog(node.getScene().getWindow()) ) { 
            boolean success = job.printPage(pageLayout, node);                   
            if (success) {
                job.endJob();
            }
        }

这是我要打印的节点的快照:


这是我打印节点时得到的

Answer 1

在您的方法中，您需要获得硬件能力余量。即使您将边距设置为 0，您的打印机在纸张周围也有不可打印的边距。

如果打印出来，您可以查看页边距:

System.out.println("PageLayout: " + pageLayout.toString());

而且您无法将边距设置为小于零的值。因此，您需要缩放将要打印的节点。该节点将被缩放、打印然后不缩放。

  public static void printNode(final Node node) throws NoSuchMethodException, InstantiationException, IllegalAccessException, InvocationTargetException {
    Printer printer = Printer.getDefaultPrinter();
    PageLayout pageLayout
        = printer.createPageLayout(Paper.A4, PageOrientation.PORTRAIT, Printer.MarginType.HARDWARE_MINIMUM);
    PrinterAttributes attr = printer.getPrinterAttributes();
    PrinterJob job = PrinterJob.createPrinterJob();
    double scaleX
        = pageLayout.getPrintableWidth() / node.getBoundsInParent().getWidth();
    double scaleY
        = pageLayout.getPrintableHeight() / node.getBoundsInParent().getHeight();
    Scale scale = new Scale(scaleX, scaleY);
    node.getTransforms().add(scale);

    if (job != null && job.showPrintDialog(node.getScene().getWindow())) {
      boolean success = job.printPage(pageLayout, node);
      if (success) {
        job.endJob();

      }
    }
    node.getTransforms().remove(scale);
  }

灵感来自此处找到的解决方案: https://carlfx.wordpress.com/2013/07/15/introduction-by-example-javafx-8-printing/