附加和缩放光栅图像 （.NET）

图像可以附着和放置在图形文件中，但它们实际上不是文件的一部分。图像通过路径名或数据管理文档 ID 链接到图形文件。链接的图像路径可以随时更改或删除。要附加图像，首先创建一个对象，其中包含有关存储在被引用磁盘上的图像文件的定义信息，然后创建一个对象。RasterImageDefRasterImage

创建对象后，将其分配给对象。对象表示您在绘图窗口中与之交互的对象，并允许您控制图像的插入点、比例、方向和外观以及其他属性。单个对象可用于多次附加图像。每个附件都有自己的剪辑边界以及自己的亮度、对比度、淡入淡出和透明度设置。RasterImageDefRasterImageRasterImageRasterImageDef

创建对象后，可以使用“缩放”特性为光栅图像设置比例因子，以便图像的几何比例与在 AutoCAD 图形中创建的几何的比例相匹配。附着图像时，将以 1 个图像度量单位到 1 个 AutoCAD 测量单位的比例因子插入图像。要设置图像比例因子，您需要知道图像上几何图形的比例，并且需要知道要用于定义 1 个 AutoCAD 单位的度量单位（英寸、英尺等）。图像文件必须包含定义 DPI 的分辨率信息、每英寸点数和图像中的像素数。RasterImage

如果图像具有分辨率信息，AutoCAD 会将其与您提供的比例因子和 AutoCAD 度量单位相结合，以在图形中缩放图像。例如，如果光栅图像是扫描的蓝图，其比例为 1 英寸等于 50 英尺或 1：600，并且 AutoCAD 图形设置为以 1 个单位表示 1 英寸，则将图像的比例因子设置为 600。AutoCAD 会缩放图像，以便使图像中的几何图形与图形中的矢量几何图形对齐。

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry

<CommandMethod("AttachRasterImage")> _
Public Sub AttachRasterImage()
    ' Get the current database and start a transaction
    Dim acCurDb As Autodesk.AutoCAD.DatabaseServices.Database
    acCurDb = Application.DocumentManager.MdiActiveDocument.Database

    Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()

        ' Define the name and image to use
        Dim strImgName As String = "WorldMap"
        Dim strFileName As String = "C:\AutoCAD\Sample\VBA\WorldMap.TIF"

        Dim acRasterDef As RasterImageDef
        Dim bRasterDefCreated As Boolean = False
        Dim acImgDefId As ObjectId

        ' Get the image dictionary
        Dim acImgDctID As ObjectId = RasterImageDef.GetImageDictionary(acCurDb)

        ' Check to see if the dictionary does not exist, it not then create it
        If acImgDctID.IsNull Then
            acImgDctID = RasterImageDef.CreateImageDictionary(acCurDb)
        End If

        ' Open the image dictionary
        Dim acImgDict As DBDictionary = acTrans.GetObject(acImgDctID, OpenMode.ForRead)

        ' Check to see if the image definition already exists
        If acImgDict.Contains(strImgName) Then
            acImgDefId = acImgDict.GetAt(strImgName)

            acRasterDef = acTrans.GetObject(acImgDefId, OpenMode.ForWrite)
        Else
            ' Create a raster image definition
            Dim acRasterDefNew As New RasterImageDef

            ' Set the source for the image file
            acRasterDefNew.SourceFileName = strFileName

            ' Load the image into memory
            acRasterDefNew.Load()

            ' Add the image definition to the dictionary
            acTrans.GetObject(acImgDctID, OpenMode.ForWrite)
            acImgDefId = acImgDict.SetAt(strImgName, acRasterDefNew)

            acTrans.AddNewlyCreatedDBObject(acRasterDefNew, True)

            acRasterDef = acRasterDefNew

            bRasterDefCreated = True
        End If

        ' Open the Block table for read
        Dim acBlkTbl As BlockTable
        acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead)

        ' Open the Block table record Model space for write
        Dim acBlkTblRec As BlockTableRecord
        acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), _
                                        OpenMode.ForWrite)

        ' Create the new image and assign it the image definition
        Using acRaster As New RasterImage
            acRaster.ImageDefId = acImgDefId

            ' Use ImageWidth and ImageHeight to get the size of the image in pixels (1024 x 768).
            ' Use ResolutionMMPerPixel to determine the number of millimeters in a pixel so you 
            ' can convert the size of the drawing into other units or millimeters based on the 
            ' drawing units used in the current drawing.

            ' Define the width and height of the image
            Dim width As Vector3d
            Dim height As Vector3d

            ' Check to see if the measurement is set to English (Imperial) or Metric units
            If acCurDb.Measurement = MeasurementValue.English Then
                width = New Vector3d((acRasterDef.ResolutionMMPerPixel.X * acRaster.ImageWidth) / 25.4, 0, 0)
                height = New Vector3d(0, (acRasterDef.ResolutionMMPerPixel.Y * acRaster.ImageHeight) / 25.4, 0)
            Else
                width = New Vector3d(acRasterDef.ResolutionMMPerPixel.X * acRaster.ImageWidth, 0, 0)
                height = New Vector3d(0, acRasterDef.ResolutionMMPerPixel.Y * acRaster.ImageHeight, 0)
            End If

            ' Define the position for the image 
            Dim insPt As New Point3d(5.0, 5.0, 0.0)

            ' Define and assign a coordinate system for the image's orientation
            Dim coordinateSystem As New CoordinateSystem3d(insPt, width * 2, height * 2)
            acRaster.Orientation = coordinateSystem

            ' Set the rotation angle for the image
            acRaster.Rotation = 0

            ' Add the new object to the block table record and the transaction
            acBlkTblRec.AppendEntity(acRaster)
            acTrans.AddNewlyCreatedDBObject(acRaster, True)

            ' Connect the raster definition and image together so the definition
            ' does not appear as "unreferenced" in the External References palette.
            RasterImage.EnableReactors(True)
            acRaster.AssociateRasterDef(acRasterDef)

            If bRasterDefCreated Then
                acRasterDef.Dispose()
            End If
        End Using

        ' Save the new object to the database
        acTrans.Commit()

        ' Dispose of the transaction
    End Using
End Sub

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;

[CommandMethod("AttachRasterImage")]
public void AttachRasterImage()
{
    // Get the current database and start a transaction
    Database acCurDb;
    acCurDb = Application.DocumentManager.MdiActiveDocument.Database;

    using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
    {
        // Define the name and image to use
        string strImgName = "WorldMap";
        string strFileName = "C:\\AutoCAD\\Sample\\VBA\\WorldMap.TIF";

        RasterImageDef acRasterDef;
        bool bRasterDefCreated = false;
        ObjectId acImgDefId;

        // Get the image dictionary
        ObjectId acImgDctID = RasterImageDef.GetImageDictionary(acCurDb);

        // Check to see if the dictionary does not exist, it not then create it
        if (acImgDctID.IsNull)
        {
            acImgDctID = RasterImageDef.CreateImageDictionary(acCurDb);
        }

        // Open the image dictionary
        DBDictionary acImgDict = acTrans.GetObject(acImgDctID, OpenMode.ForRead) as DBDictionary;

        // Check to see if the image definition already exists
        if (acImgDict.Contains(strImgName))
        {
            acImgDefId = acImgDict.GetAt(strImgName);

            acRasterDef = acTrans.GetObject(acImgDefId, OpenMode.ForWrite) as RasterImageDef;
        }
        else
        {
            // Create a raster image definition
            RasterImageDef acRasterDefNew = new RasterImageDef();

            // Set the source for the image file
            acRasterDefNew.SourceFileName = strFileName;

            // Load the image into memory
            acRasterDefNew.Load();

            // Add the image definition to the dictionary
            acTrans.GetObject(acImgDctID, OpenMode.ForWrite);
            acImgDefId = acImgDict.SetAt(strImgName, acRasterDefNew);

            acTrans.AddNewlyCreatedDBObject(acRasterDefNew, true);

            acRasterDef = acRasterDefNew;

            bRasterDefCreated = true;
        }

        // Open the Block table for read
        BlockTable acBlkTbl;
        acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead) as BlockTable;

        // Open the Block table record Model space for write
        BlockTableRecord acBlkTblRec;
        acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],
                                        OpenMode.ForWrite) as BlockTableRecord;

        // Create the new image and assign it the image definition
        using (RasterImage acRaster = new RasterImage())
        {
            acRaster.ImageDefId = acImgDefId;

            // Use ImageWidth and ImageHeight to get the size of the image in pixels (1024 x 768).
            // Use ResolutionMMPerPixel to determine the number of millimeters in a pixel so you 
            // can convert the size of the drawing into other units or millimeters based on the 
            // drawing units used in the current drawing.

            // Define the width and height of the image
            Vector3d width;
            Vector3d height;

            // Check to see if the measurement is set to English (Imperial) or Metric units
            if (acCurDb.Measurement == MeasurementValue.English)
            {
                width = new Vector3d((acRasterDef.ResolutionMMPerPixel.X * acRaster.ImageWidth) / 25.4, 0, 0);
                height = new Vector3d(0, (acRasterDef.ResolutionMMPerPixel.Y * acRaster.ImageHeight) / 25.4, 0);
            }
            else
            {
                width = new Vector3d(acRasterDef.ResolutionMMPerPixel.X * acRaster.ImageWidth, 0, 0);
                height = new Vector3d(0, acRasterDef.ResolutionMMPerPixel.Y * acRaster.ImageHeight, 0);
            }

            // Define the position for the image 
            Point3d insPt = new Point3d(5.0, 5.0, 0.0);

            // Define and assign a coordinate system for the image's orientation
            CoordinateSystem3d coordinateSystem = new CoordinateSystem3d(insPt, width * 2, height * 2);
            acRaster.Orientation = coordinateSystem;

            // Set the rotation angle for the image
            acRaster.Rotation = 0;

            // Add the new object to the block table record and the transaction
            acBlkTblRec.AppendEntity(acRaster);
            acTrans.AddNewlyCreatedDBObject(acRaster, true);

            // Connect the raster definition and image together so the definition
            // does not appear as "unreferenced" in the External References palette.
            RasterImage.EnableReactors(true);
            acRaster.AssociateRasterDef(acRasterDef);

            if (bRasterDefCreated)
            {
                acRasterDef.Dispose();
            }
        }

        // Save the new object to the database
        acTrans.Commit();

        // Dispose of the transaction
    }
}

Sub AttachRasterImage()
    Dim insertionPoint(0 To 2) As Double
    Dim scalefactor As Double
    Dim rotationAngle As Double
    Dim imageName As String
    Dim rasterObj As AcadRasterImage
    imageName = "C:/AutoCAD/sample/VBA/WorldMap.TIF"
    insertionPoint(0) = 5
    insertionPoint(1) = 5
    insertionPoint(2) = 0
    scalefactor = 2
    rotationAngle = 0

    On Error GoTo ERRORHANDLER
    ' Attach the raster image in model space
    Set rasterObj = ThisDrawing.ModelSpace.AddRaster(imageName, insertionPoint, _
                                                     scalefactor, rotationAngle)
    ZoomAll
 Exit Sub

ERRORHANDLER:
    MsgBox Err.Description
End Sub