C#中使用PrintDocument打印PDF时如何设置Actual Size（实际尺寸）

我在C#程序中使用Crystal Reports打印提货单，必须先将报表导出为PDF再执行打印。现在需要确保调用PrintDocument打印时，不会自动执行页面适配（fit to page），要实现打印机设置界面中“Actual Size”（实际尺寸）选项的效果，目前查阅资料未找到明确方案。

现有代码 #

PrinterSettings printerSettings = new PrinterSettings();
System.Drawing.Printing.PageSettings pageSettings = new System.Drawing.Printing.PageSettings(printerSettings);

printerSettings.PrinterName = toPrinter;
printerSettings.Duplex = Duplex.Simplex;
//printerSettings.FromPage = 1;
//printerSettings.ToPage = 3;

PaperSource ps = new PaperSource();
ps.RawKind = (int)PaperSourceKind.Middle;
printerSettings.DefaultPageSettings.PaperSource = ps;

PrintDocument printDocument = document.CreatePrintDocument();
printDocument.PrinterSettings = printerSettings;
printDocument.PrintController = new StandardPrintController();
PrintingPermission perm = new PrintingPermission(System.Security.Permissions.PermissionState.Unrestricted);
perm.Level = PrintingPermissionLevel.AllPrinting;
// Something here to set "Actual Size"

// The Big MOMENT!!!

printDocument.Print();

解决方案 #

要实现“Actual Size”的效果，需要从页面设置和缩放控制两方面入手：

• 禁用页面自动适配：设置PageSettings.FitToPage为false，阻止打印机自动将内容适配到打印区域。
• 强制100%缩放比例：将PageSettings.Zoom设为100，确保内容按原始尺寸打印。
• 匹配纸张尺寸：确保打印使用的纸张尺寸与Crystal Reports设计时的尺寸完全一致，避免打印机自动调整。

修改后的代码 #

PrinterSettings printerSettings = new PrinterSettings();
System.Drawing.Printing.PageSettings pageSettings = new System.Drawing.Printing.PageSettings(printerSettings);

printerSettings.PrinterName = toPrinter;
printerSettings.Duplex = Duplex.Simplex;
//printerSettings.FromPage = 1;
//printerSettings.ToPage = 3;

PaperSource ps = new PaperSource();
ps.RawKind = (int)PaperSourceKind.Middle;
printerSettings.DefaultPageSettings.PaperSource = ps;

// 关键设置：启用实际尺寸打印
pageSettings.FitToPage = false;
pageSettings.Zoom = 100; // 强制100%缩放
// 可选：如果知道报表的纸张尺寸，直接指定避免自动适配
// pageSettings.PaperSize = new PaperSize(PaperName.Custom, reportWidth, reportHeight);

PrintDocument printDocument = document.CreatePrintDocument();
printDocument.PrinterSettings = printerSettings;
printDocument.DefaultPageSettings = pageSettings; // 应用修改后的页面设置
printDocument.PrintController = new StandardPrintController();
PrintingPermission perm = new PrintingPermission(System.Security.Permissions.PermissionState.Unrestricted);
perm.Level = PrintingPermissionLevel.AllPrinting;

printDocument.Print();

补充说明 #

如果上述设置仍未生效，可能是PDF导出过程中已经引入了缩放适配，需要检查Crystal Reports的导出设置：

• 在导出PDF时，确保勾选“无缩放”或“实际尺寸”选项
• 确认报表设计的页面边距与打印机的可打印区域匹配，避免打印机因边距问题自动调整

内容的提问来源于stack exchange，提问作者j.hull