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The RxDisplay Object

Component name: RxViewCOM.dll

RxDisplay Methods​

Draw​

Displays the active page of the given document on the specified device context. Use parameters such as scale and rotation to control how the document is drawn.

Syntax​

Draw(long DC, LPDISPATCH Doc, double Rotation, long DspL, long DspT, long DspW, long DspH, double FileL, double FileT, double XScale, double YScale)

Parameters​

  • DC: Device context handle.
  • Doc: Document (IRxDoc) pointer.
  • Rotation: Rotation factor in degrees.
  • DspL: Left start position of the drawn document (device coordinates).
  • DspT: Top start position of the drawn document (device coordinates).
  • DspW: Width of the displayed area (device coordinates).
  • DspH: Height of the displayed area (device coordinates).
  • FileL: X-coordinate of the point in the document corresponding to the display start position.
  • FileT: Y-coordinate of the point in the document corresponding to the display start position.
  • XScale: X-scaling factor.
  • YScale: Y-scaling factor.

Returns​

  • HRESULT: S_OK on success, E_FAIL on failure.

DrawFit​

Displays the given document on the specified device context, scaling it to fit the given display area.

Syntax​

DrawFit(long DC, LPDISPATCH Doc, long DspL, long DspT, long DspW, long DspH)

Parameters​

  • DC: Device context handle.
  • Doc: Document (IRxDoc) pointer.
  • DspL: Left start position of the drawn document (device coordinates).
  • DspT: Top start position of the drawn document (device coordinates).
  • DspW: Width of the display area (device coordinates).
  • DspH: Height of the display area (device coordinates).

Returns​

  • HRESULT: S_OK on success, E_FAIL on failure.

DrawPreview​

Displays the given preview handle on the specified device context. Previews are available only for certain formats (e.g., AutoCAD DWG).

Syntax​

DrawPreview(long DC, long Preview, long Left, long Top, long Width, long Height, long Aspect)

Parameters​

  • DC: Device context handle where the preview will be drawn.
  • Preview: Preview handle, obtainable using the IRxDoc Check method.
  • Left: Left start position of the drawn preview (device coordinates).
  • Top: Top start position of the drawn preview (device coordinates).
  • Width: Width of the display area (device coordinates).
  • Height: Height of the display area (device coordinates).
  • Aspect: Set to 1 to maintain aspect ratio (forces equal scaling in X and Y).

Returns​

  • HRESULT: S_OK on success, E_FAIL on failure.

SetPDFConfig​

Customizes the PDF renderer using this method.

Syntax​

SetPDFConfig(enumPDFConfig ID, VARIANT Param)

Parameters​

  • ID: One of the following configuration IDs:
    • 0: Disable anti-aliasing (typically used for printing PDFs where grayscale can produce faint results). Param is a boolean.
    • 1: Set the DPI value for PDF comparison (overlays images; higher DPI improves results, default is 200). Param is an integer.
  • Param: Value to set for the given configuration ID (type depends on ID; see above).

Returns​

  • HRESULT: S_OK on success, E_FAIL on failure.

RxDisplay Properties​

PropertyTypeAccessDescription
ApplyPenTableToTextlongRead/WriteIf true, the pen table is applied to text elements drawn using line geometry.
BackgroundColorlongRead/WriteBackground color used for drawing.
CompareModelongRead/WriteIf true, documents are drawn in compare mode.
DeviceDPIlongRead/WriteSets the DPI for display, overriding the device handle (hDC) DPI. Useful for rasterizing to bitmaps.
ExtentsColorlongRead/WriteColor used for drawing extents (requires ShowExtents to be enabled).
FillPolygonslongRead/WriteIf true, polygons are drawn filled; if false, they are drawn outlined.
HalfTonelongRead/WriteIf true, color images are drawn using halftone (a form of anti-aliasing).
HiddenLineRemovallongRead/WriteIf true, hidden lines are removed when a 3D model is shown in wireframe mode.
KeepDrawColorslongRead/WriteIf true, document colors are always used; otherwise, colors close to the background may be inverted.
LineWeightslongRead/WriteIf true, line weights are displayed (if defined in the drawing).
MonoColorlongRead/WriteColor used for monochrome drawing (requires MonoDisplay to be enabled).
MonoDisplaylongRead/WriteIf true, files are drawn using a single color (MonoColor).
PDFCacheImageDPIlongRead/WriteSets the DPI for the cached raster image when UsePDFCacheImage is enabled (higher DPI increases quality but memory usage).
PenTableScaledoubleRead/WriteScale factor for pen table widths when drawing (default is 1.0).
RasterDrawMethodlongRead/WriteControls raster document drawing: 0 (normal), 1 (anti-aliasing, scale-to-gray for monochrome), 2 (preserve black pixels).
RasterMergeComparelongRead/WriteIf true, common drawing info is shown in black; if false, identical info is shown in green.
ShowExtentslongRead/WriteIf true, document extents are drawn by the draw methods.
ShowGridlongRead/WriteIf true, spreadsheet grid lines are shown.
UseExtPenlongRead/WriteIf true, lines are drawn with higher quality (slower); disable for faster drawing.
UseGDIPluslongRead/WriteIf true, uses GDI+ for rendering (improves quality with anti-aliasing but slower than GDI).
UsePDFCacheImagelongRead/WriteIf true, uses a raster image for PDF display instead of rendering each redraw (improves performance for raster-converted PDFs).
UsePenTablelongRead/WriteIf true, the pen table is used when drawing the document.
UsePlotLayerSettingslongRead/WriteIf true, layers with plottable set to false are not drawn.
VersionBSTRRead/WriteReturns the RxViewCOM version as a string (Product Version, Main Revision, Sub Revision, Build Number).
WireFramelongRead/WriteIf true, 3D models are drawn in wireframe mode (no shading).