如何使用 Microsoft.Office.Interop.Word.Document.PrintOut() 将 docx 打印到特定打印机

这似乎是一个简单的需求，但由于某种原因我找不到如何实现这一点。我有这样的代码：

Microsoft.Office.Interop.Word.Application word = new Microsoft.Office.Interop.Word.Application();
MemoryStream documentStream = getDocStream();
FileInfo wordFile = new FileInfo("c:\\test.docx");
object fileObject = wordFile.FullName;
object oMissing = System.Reflection.Missing.Value;
Microsoft.Office.Interop.Word.Document doc = wordInstance.Documents.Open(ref fileObject, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing);
doc.Activate();
doc.PrintOut(oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing);

我需要一个配置设置驱动器来使用打印机和托盘。搜索后，我发现 Microsoft.Office.Interop.Word.Application.ActivePrinter 这是一个可设置的字符串属性，文档说它采用“活动打印机的名称”，但我不知道这对于打印机来说意味着什么“活动打印机”，尤其是当我有两个时。如何才能做到这一点？

TL;DR您无法打印到特定打印机。您必须将默认打印机更改为您想要使用的打印机。然后正常打印。

自从我们第一次在这个领域开展工作以来，情况可能已经发生了巨大的变化，但我们无法找到任何方法来打印到特定的打印机。因此，我们所做的就是将系统的默认打印机更改为我们想要的，在该计算机上打印我们想要的所有文档，然后将其改回之前的状态。 （实际上，我们不再将其更改回来，因为没有其他任何东西需要任何特定的默认打印机，所以这并不重要）。

简短回答：

Microsoft.Office.Interop.Word._Application _app = [some valid COM instance];
Microsoft.Office.Interop.Word.Document doc = _app.Documents.Open(ref fileName, ...);
doc.Application.ActivePrinter = "name of printer";
doc.PrintOut(/* ref options */);

但是，我们发现这非常不可靠！请阅读以获得更多详情：

如果您还没有这样做，我强烈建议您构建自己的包装类来处理所有平凡的工作_Document and _Application。现在可能没有以前那么糟糕了（dynamic对我们来说不是一个选择），但这仍然是一个好主意。您会注意到，其中缺少某些美味的代码......我试图将重点放在与您所要求的内容相关的代码上。还有，这个DocWrapper类是代码中许多独立部分的合并——请原谅这种混乱。最后，如果您认为异常处理很奇怪（或者只是抛出异常而导致设计不佳），请记住我正在尝试将来自许多地方的部分代码组合在一起（同时也忽略了我们自己的自定义类型）。阅读代码中的注释，它们很重要。

class DocWrapper
{
  private const int _exceptionLimit = 4;

  // should be a singleton instance of wrapper for Word
  // the code below assumes this was set beforehand
  // (e.g. from another helper method)
  private static Microsoft.Office.Interop.Word._Application _app;

  public virtual void PrintToSpecificPrinter(string fileName, string printer)
  {
    // Sometimes Word fails, so needs to be restarted.
    // Sometimes it's not Word's fault.
    // Either way, having this in a retry-loop is more robust.
    for (int retry = 0; retry < _exceptionLimit; retry++)
    {
      if (TryOncePrintToSpecificPrinter(fileName, printer))
        break;

      if (retry == _exceptionLimit - 1) // this was our last chance
      {
        // if it didn't have actual exceptions, but was not able to change the printer, we should notify somebody:
        throw new Exception("Failed to change printer.");
      }
    }
  }

  private bool TryOncePrintToSpecificPrinter(string fileName, string printer)
  {
    Microsoft.Office.Interop.Word.Document doc = null;

    try
    {
      doc = OpenDocument(fileName);

      if (!SetActivePrinter(doc, printer))
        return false;

      Print(doc);

      return true; // we did what we wanted to do here
    }
    catch (Exception e)
    {
      if (retry == _exceptionLimit)
      {
        throw new Exception("Word printing failed.", e);
      }
      // restart Word, remembering to keep an appropriate delay between Quit and Start.
      // this should really be handled by wrapper classes
    }
    finally
    {
      if (doc != null)
      {
        // release your doc (COM) object and do whatever other cleanup you need
      }
    }

    return false;
  }

  private void Print(Microsoft.Office.Interop.Word.Document doc)
  {
    // do the actual printing:
    doc.Activate();
    Thread.Sleep(TimeSpan.FromSeconds(1)); // emperical testing found this to be sufficient for our system
    // (a delay may not be required for you if you are printing only one document at a time)
    doc.PrintOut(/* ref objects */);
  }

  private bool SetActivePrinter(Microsoft.Office.Interop.Word.Document doc, string printer)
  {
    string oldPrinter = GetActivePrinter(doc); // save this if you want to preserve the existing "default"

    if (printer == null)
      return false;

    if (oldPrinter != printer)
    {
      // conditionally change the default printer ...
      // we found it inefficient to change the default printer if we don't have to. YMMV.
      doc.Application.ActivePrinter = printer;
      Thread.Sleep(TimeSpan.FromSeconds(5)); // emperical testing found this to be sufficient for our system
      if (GetActivePrinter(doc) != printer)
      {
        // don't quit-and-restart Word, this one actually isn't Word's fault -- just try again
        return false;
      }

      // successful printer switch! (as near as anyone can tell)
    }

    return true;
  }

  private Microsoft.Office.Interop.Word.Document OpenDocument(string fileName)
  {
    return _app.Documents.Open(ref fileName, /* other refs */);
  }

  private string GetActivePrinter(Microsoft.Office.Interop.Word._Document doc)
  {
    string activePrinter = doc.Application.ActivePrinter;
    int onIndex = activePrinter.LastIndexOf(" on ");
    if (onIndex >= 0)
    {
      activePrinter = activePrinter.Substring(0, onIndex);
    }
    return activePrinter;
  }
}