Question

我有两个程序，一个是Windows服务，另一个是Windows窗体应用程序。它们具有完全相同的代码，用于打印一个A4页面。它们都打印到同一台网络打印机，然后开始在0,0位置绘图。

private void pd_PrintCustomsDocument(object sender, PrintPageEventArgs ev)
{
  Graphics g = ev.Graphics;

  g.PageUnit = GraphicsUnit.Millimeter;
  using (Font courierBig = new Font("Courier", 15))
  {
    g.DrawString("Shipping Invoice", courierBig, Brushes.Black, new Point(0, 0));
    // etc
  }
}

Windows窗体应用程序正确打印文档，使用页边距。但该服务正好在纸张的边缘开始打印。从服务和Windows窗体应用程序打印gdi +之间有区别吗？

实际打印的代码分为基础和子类，用于覆盖默认打印机设置，例如从不同托盘中选择页面：

public class PrintBehaviour : IDisposable
{
    private string mPrinterName;
    private PrintPageEventHandler mHandler;
    private PrintDocument mDocument = new PrintDocument();

    public PrintBehaviour(string name, PrintPageEventHandler handler)
    {
        mPrinterName = name;
        mHandler = handler;
        mDocument.PrintController = new StandardPrintController();
    }

    public virtual void SettingsOverride(PrintDocument doc) {}

    public void Print()
    {
        SettingsOverride(mDocument);
        mDocument.PrinterSettings.PrinterName = mPrinterName;
        mDocument.PrintPage += new PrintPageEventHandler(mHandler);
        mDocument.Print();
    }

    public void Dispose()
    {
        mDocument.Dispose();
    }
}

public sealed class CustomsPrintBehaviour : PrintBehaviour
{
    private string mPaperTray;

    public CustomsPrintBehaviour(string name, PrintPageEventHandler handler, string paperTray)
        : base(name, handler)
    {
        mPaperTray = paperTray;
    }

    public override void SettingsOverride(PrintDocument doc)
    {
        base.SettingsOverride(doc);
        doc.DefaultPageSettings.Landscape = true;

        foreach (PaperSource source in doc.PrinterSettings.PaperSources)
        {
            if (source.SourceName.Trim().ToUpper() == mPaperTray)
            {
                doc.DefaultPageSettings.PaperSource = source;

                PaperSize size = new PaperSize { RawKind = (int)PaperKind.A4 };

                doc.DefaultPageSettings.PaperSize = size;
                break;
            }
        }
    }
}

并且这样调用：

using (var pb = new CustomsPrintBehaviour(_customsPrinter, pd_PrintCustomsDocument, kv["PaperTray"].ToUpper()))
{
  pb.Print();
}

Answer 1

来自MSDN：

GDI +函数和类不支持在a中使用 Windows服务。试图使用这些函数和类 Windows服务可能会产生意外问题，例如减少服务性能和运行时异常或错误。

来自完全相同代码的不同打印结果

1 个答案: