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，