c# - 如何以编程方式打印 PrintDocument 中的特定页面？

Question

有没有办法以编程方式仅打印 System.Drawing.Printing.PrintDocument 中的选定页面(例如第 3-5 页)？

我正在使用这段代码:

myPrintDocument.Print();

但那样我就无法以编程方式跳过页面。我考虑过显示 modified version of the PrintDialog class 的可能性，跳过我不想要的页面，打印文档并以编程方式关闭 PrintDialog 窗口(以便它只闪烁)。但这有点像 hack。

Answer 1

您可以在 PrintDocument.BeginPrint 事件中设置 PrinterSettings。

PrintDocument.PrintPage 事件，您放置打印代码的地方将由打印 Controller 引发，用于每一页，直到 PrinterSettings 中设置的最后一页。例如，如果您有一个 10 页的 PrintDocument 并且您设置了 PrintDocument.PrinterSettings.ToPage = 5，那么打印 Controller 将提升 PrintPage 每个页面的事件，直到它处理第 5 个页面。

如果您正在跳过页面，例如 PrinterSettings.FromPage = 3 到 ToPage = 5，那么打印 Controller 将引发一个 PrintPage事件3次。这是从 3 到 5(含)的每个计数一次 PrintPage 事件。

打印 Controller 不决定 PrintPage 事件打印什么内容。它只会在您范围内的每个计数页面引发一次事件。例如，如果您将 FromPage = 4 指定为 FromPage = 6，打印 Controller 将引发完全相同数量的 PrintPage 事件，但它不会甚至不知道区别!它不知道正在使用 PrintPage 事件打印哪一页。它只知道引发 3 次 PrintPage 事件。

我的观点是，您在 PrintPage 事件中的代码必须处理所有跳过的页面而不绘制任何内容。然后您在同一 PrintPage 事件中的代码必须处理并绘制您要打印的“当前页面”，然后返回以便打印 Controller 可以引发下一个 PrintPage 事件.

伪代码如下:

void Setup_Printing()
{
  myPrintDocument.BeginPrint += On_BeginPrint;
  myPrintDocument.PrintPage += On_PrintPage;
}

// Page Index variable
int indexCuurentPage = 0;

void On_BeginPrint(object sender, PrintEventArgs e)
{
  indexCuurentPage = 0;
  ((PrintDocument)sender).PrinterSettings.PrintRange = PrintRange.SomePages;
  ((PrintDocument)sender).PrinterSettings.FromPage = 3;
  ((PrintDocument)sender).PrinterSettings.ToPage = 5;
}


void On_PrintPage(object sender, PrintPageEventArgs ppea)
{
  // Set up a loop to process pages.
  bool bProcessingPages = true;
  while (bProcessingPages)
  {
    indexCurrentPage++;

    // Set isPageInRange flag to true if this indexCurrentPage is in the selected range of pages
    bool isPageInRange = (theCurrentPage >= ppea.PageSettings.PrinterSettings.FromPage);
    isPageInRange = isPageInRange && (theCurrentPage =< ppea.PageSettings.PrinterSettings.ToPage);

    if (isPageInRange)
    {
      // Process your data and print this page then exit the loop.  
      try
      {
        //// TO DO - Process Data ////
        //// TO DO - Draw Data to ppea.Graphics ////
        // Note:  Do not set the ppea.HasMorePages to true.  Let the Printer Controller do it.
      }
      catch
      {
        // Abort printing more pages if there was an error.
        ppea.HasMorePages = false;
      }
      // Set the loop exit flag.  We could use "return;" instead if we do not want to do more.
      bProcessingPages = false;
    }
    else
    {
      // Process your data and Do Not Draw on the ppea.Graphics.
      try
      {
        //// TO DO - Process Data ////
      }
      catch
      {
        // Abort printing more pages if there was an error.
        ppea.HasMorePages = false;
        // Set the loop exit flag.  We could use "return;" instead if we do not want to do more.
        bProcessingPages = false;
      }
      // Stay in the processing loop until you either need to actually Print a Page
      // or until you run out of data and pages to print.
    }

    // check to see if we ran out of pages to print
    if (indexCurrentPage >= ppea.PageSettings.PrinterSettings.ToPage)
    {
      // Done.  We do not need to set the HasMorePages = false
      bProcessingPages = false;
    }
  } // end while processing pages

  // The print controller will decide to raise the next PrintPage event if it needs to.
  // If You set the ppea.HasMorePages = false, then it will stop any more page events. 
  // If You set the ppea.HasMorePages = true, 
  //    then I'm not sure what the print controller will do if it ran out of pages!
}