AutoCAD按坐标打印图纸

前几天公司要求按坐标打印DWG文件，中间走了不少弯路，好在已经搞定了，整理一下分享给大家，希望后来人少走弯路。

1. 设计需求：

公司的图纸用AutoCAD2010做成，通常一个项目的所有图纸都存放在一个DWG文件内，根据具体的子项不同，放在不同的块引用里，我要做的是找到每一个块引用，并把他打印到bmp文件里。

2.实现思路：

利用AutoCAD的.net API，找到符合条件的快引用，得到块引用左下角和右上角的点的坐标，把两点坐标框选的矩形区域发给打印机打印

3.遇到的问题

有的图纸打印没有问题，有的图纸打印出一张空白图。

4.解决问题（在这里向业界大牛Kean同志表示强烈的感谢，感谢他无私的帮助）

之所以有些图纸打印出白图是因为坐标体系的问题，AutoCAD中有很多种坐标体系，例如UCS世界坐标，DCS显示设备坐标，UCS用户坐标等等，除了UCS坐标其他各坐标体系都是UCS坐标推衍而来，UCS坐标是永远不变的。.net API取出的块引用坐标是UCS，而要向打印机输出坐标打印命令需要用DCS坐标。也就是说不把UCS转换为DCS，图纸就会打印出白图，碰巧打印出来的是因为UCS和DCS重合。

很遗憾，AutoCAD .net ＡＰＩ并没有转换坐标的函数，幸运的是ObjectARX 中有acedTrans（）函数，于是先要把此函数引入我们自己的工程，加入如下代码

public partial class BlockSelectForm : Form
    {
        [DllImport("acad.exe",
               CallingConvention = CallingConvention.Cdecl,
               EntryPoint = "acedTrans")
        ]
        static extern int acedTrans(
          double[] point,
          IntPtr fromRb,
          IntPtr toRb,
          int disp,
          double[] result
        );
．．．．

private Extents2d Ucs2Dcs(Point3d objStart,Point3d objEnd)
        {
            ResultBuffer rbFrom =
                new ResultBuffer(new TypedValue(5003, 1)),
                rbTo =
                new ResultBuffer(new TypedValue(5003, 2));
 
            double[] firres = new double[] { 0, 0, 0 };
            double[] secres = new double[] { 0, 0, 0 };

            acedTrans(
                objStart.ToArray(),
                rbFrom.UnmanagedObject,
                rbTo.UnmanagedObject,
                0,
                firres
            );
 
            acedTrans(
                objEnd.ToArray(),
                rbFrom.UnmanagedObject,
                rbTo.UnmanagedObject,
                0,
                secres
            );
 
            Extents2d window =
              new Extents2d(
                firres[0],
                firres[1],
                secres[0],
                secres[1]
              );
            return window;
        }

下面是打印函数代码

private string PrintBMP(Point3d objStart, Point3d objEnd, string strPrintName, string strPaperName, string strStyleName,
            string strRotation)
        {
            // 打开文档数据库
            Document acDoc =Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument;
            Database acCurDb = acDoc.Database;
            Extents2d objPoint = Ucs2Dcs(objStart, objEnd);
            string strFileName = string.Empty;
 
            using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
            {
                BlockTableRecord btr =
                          (BlockTableRecord)acTrans.GetObject(
                            acCurDb.CurrentSpaceId,
                            OpenMode.ForRead
                          );
 
                Layout acLayout =
                    (Layout)acTrans.GetObject(
                        btr.LayoutId,
                    OpenMode.ForRead
                    );
 
                // Get the PlotInfo from the layout
                PlotInfo acPlInfo = new PlotInfo();
                acPlInfo.Layout = btr.LayoutId;
 
                // Get a copy of the PlotSettings from the layout
                PlotSettings acPlSet = new PlotSettings(acLayout.ModelType);
                acPlSet.CopyFrom(acLayout);
 
                // Update the PlotSettings object
                PlotSettingsValidator acPlSetVdr = PlotSettingsValidator.Current;
 
                acPlSetVdr.SetPlotWindowArea(acPlSet, objPoint);
                // Set the plot type
                acPlSetVdr.SetPlotType(acPlSet,
                                       Autodesk.AutoCAD.DatabaseServices.PlotType.Window);
 
                // Set the plot scale
                acPlSetVdr.SetUseStandardScale(acPlSet, true);
                acPlSetVdr.SetStdScaleType(acPlSet, StdScaleType.ScaleToFit);
 
                // Center the plot
                acPlSetVdr.SetPlotCentered(acPlSet, true);
 
                // Set the plot device to use
                acPlSetVdr.SetPlotConfigurationName(acPlSet, strPrintName,
                                                    strPaperName);
 
                acPlSetVdr.RefreshLists(acPlSet);
                acPlSetVdr.SetCurrentStyleSheet(acPlSet, strStyleName);
 
                switch (strRotation)
                {
                    case "0":
                         acPlSetVdr.SetPlotRotation(acPlSet,PlotRotation.Degrees000);
                        break;
                    case "90":
                        acPlSetVdr.SetPlotRotation(acPlSet, PlotRotation.Degrees090);
                        break;
                    case "180":
                        acPlSetVdr.SetPlotRotation(acPlSet, PlotRotation.Degrees180);
                        break;
                    case "270":
                        acPlSetVdr.SetPlotRotation(acPlSet, PlotRotation.Degrees270);
                        break;
                }
 
                // Set the plot info as an override since it will
                // not be saved back to the layout
                acPlInfo.OverrideSettings = acPlSet;
 
                // Validate the plot info
                PlotInfoValidator acPlInfoVdr = new PlotInfoValidator();
                acPlInfoVdr.MediaMatchingPolicy = MatchingPolicy.MatchEnabled;
                acPlInfoVdr.Validate(acPlInfo);
 
                // Check to see if a plot is already in progress
                if (PlotFactory.ProcessPlotState == ProcessPlotState.NotPlotting)
                {
                    using (PlotEngine acPlEng = PlotFactory.CreatePublishEngine())
                    {
                        // Track the plot progress with a Progress dialog
                        PlotProgressDialog acPlProgDlg = new PlotProgressDialog(false,
                                                                                1,
                                                                                false);
 
                        using (acPlProgDlg)
                        {
                            // Define the status messages to display when plotting starts
                            acPlProgDlg.set_PlotMsgString(PlotMessageIndex.DialogTitle,
                                                          "我们公司名，隐去了");
 
                            acPlProgDlg.set_PlotMsgString(PlotMessageIndex.CancelJobButtonMessage,
                                                          "Cancel Job");
 
                            acPlProgDlg.set_PlotMsgString(PlotMessageIndex.CancelSheetButtonMessage,
                                                          "Cancel Sheet");
 
                            acPlProgDlg.set_PlotMsgString(PlotMessageIndex.SheetSetProgressCaption,
                                                          "Sheet Set Progress");
 
                            acPlProgDlg.set_PlotMsgString(PlotMessageIndex.SheetProgressCaption,
                                                          "正在生成" + acDoc.Name);
 
                            // Set the plot progress range
                            acPlProgDlg.LowerPlotProgressRange = 0;
                            acPlProgDlg.UpperPlotProgressRange = 100;
                            acPlProgDlg.PlotProgressPos = 0;
 
                            // Display the Progress dialog
                            acPlProgDlg.OnBeginPlot();
                            acPlProgDlg.IsVisible = true;
 
                            // Start to plot the layout
                            acPlEng.BeginPlot(acPlProgDlg, null);
 
                            string strTempPath = System.IO.Path.GetTempPath();
                            strFileName = Path.Combine(strTempPath,
                                acDoc.Name.Substring(acDoc.Name.LastIndexOf("\\")+1).Replace("dwg","")
                                + DateTime.Now.ToString("yyyyMMddhhmmssfff") + "Compare" + ".bmp");
 
                            // Define the plot output
                            acPlEng.BeginDocument(acPlInfo,
                                                  acDoc.Name,
                                                  null,
                                                  1,
                                                  true,
                                                  strFileName);
 
                            // Display information about the current plot
                            acPlProgDlg.set_PlotMsgString(PlotMessageIndex.Status,
                                                          "Plotting: " + acDoc.Name + " - " +
                                                          acLayout.LayoutName);
 
                            // Set the sheet progress range
                            acPlProgDlg.OnBeginSheet();
                            acPlProgDlg.LowerSheetProgressRange = 0;
                            acPlProgDlg.UpperSheetProgressRange = 100;
                            acPlProgDlg.SheetProgressPos = 0;
 
                            // Plot the first sheet/layout
                            PlotPageInfo acPlPageInfo = new PlotPageInfo();
                            acPlEng.BeginPage(acPlPageInfo,
                                              acPlInfo,
                                              true,
                                              null);
 
                            acPlEng.BeginGenerateGraphics(null);
                            acPlEng.EndGenerateGraphics(null);
 
                            // Finish plotting the sheet/layout
                            acPlEng.EndPage(null);
                            acPlProgDlg.SheetProgressPos = 100;
                            acPlProgDlg.OnEndSheet();
 
                            // Finish plotting the document
                            acPlEng.EndDocument(null);
 
                            // Finish the plot
                            acPlProgDlg.PlotProgressPos = 100;
                            acPlProgDlg.OnEndPlot();
                            acPlEng.EndPlot(null);
                        }
                    }
                }
            }
            return strFileName;
        }

先写这么多了，欢迎交流吐槽，