对比度属性 （ActiveX）

签名

工 务 局：

object.Contrast

对象

类型：DgnUnderlay，DwfUnderlay，GeomapImage，PdfUnderlay，RasterImage，Wipeout

此属性适用的对象。

属性值

只读：不

类型：整数

有效范围为 0 到 100（含 0 和 100）。默认值为 50。

言论

您可以调整图像亮度、对比度和淡入淡出以显示图像以及打印输出，而不会影响原始光栅图像或参考底图文件。调整亮度以使图像变暗或变亮。调整对比度以使质量较差的图像更易于阅读。调整淡入淡出以使矢量更易于在图像上看到，并在打印的输出中创建水印效果。

例子

工 务 局：

Sub Example_Contrast()
    ' This example inserts a raster image and finds the current
    ' Contrast of the image. It then changes the Contrast
    ' of the image.
    
    ' This example uses the "2d Projected Polylines.jpg" found in the Sample
    ' directory. If you do not have the image, or if it is located
    ' in a different directory, insert a valid path and name for the
    ' imageName variable below.
    Dim insertionPoint(0 To 2) As Double
    Dim scalefactor As Double
    Dim rotAngleInDegree As Double
    Dim rotAngle As Double
    Dim imageName As String
    Dim raster As AcadRasterImage
    imageName = "C:\AutoCAD\sample\2d Projected Polylines.jpg"
    insertionPoint(0) = 2#: insertionPoint(1) = 2#: insertionPoint(2) = 0#
    scalefactor = 1#
    rotAngleInDegree = 0#
    rotAngle = rotAngleInDegree * 3.141592 / 180#
    
    On Error Resume Next
    
    ' Creates a raster image in model space
    Set raster = ThisDrawing.modelSpace.AddRaster(imageName, insertionPoint, scalefactor, rotAngle)
    If Err.Description = "File error" Then
        MsgBox imageName & " could not be found."
        Exit Sub
    End If

    ' Find the current Contrast
    ThisDrawing.Regen True
    MsgBox "The Contrast is currently set to: " & raster.Contrast, vbInformation
    
    ' Change the Contrast to 5
    raster.Contrast = 5
    ThisDrawing.Regen True
    MsgBox "The Contrast is now set to: " & raster.Contrast, vbInformation
End Sub

Visual LISP：

(vl-load-com)
(defun c:Example_Contrast()
    ;; This example inserts a raster image and finds the current
    ;; Contrast of the image. It then changes the Contrast
    ;; of the image.
    (setq acadObj (vlax-get-acad-object))
    (setq doc (vla-get-ActiveDocument acadObj))

    ;; This example uses the "2d Projected Polylines.jpg" found in the Sample
    ;; directory. If you do not have the image, or if it is located
    ;; in a different directory, insert a valid path and name for the
    ;; imageName variable below.
    (setq insertionPoint (vlax-3d-point 2 2 0)
          imageName ".\\Sample\\VBA\\2d Projected Polylines.jpg"
          scalefactor 1
          rotAngleInDegree 0
          rotAngle (/ (* rotAngleInDegree 3.141592) 180))

    (if (/= (findfile ".\\Sample\\VBA\\2d Projected Polylines.jpg") nil)
        (progn
            ;; Creates a raster image in model space
            (setq modelSpace (vla-get-ModelSpace doc))
            (setq raster (vla-AddRaster modelSpace (findfile ".\\Sample\\VBA\\2d Projected Polylines.jpg") insertionPoint scalefactor rotAngle))
            (vla-ZoomExtents acadObj)

            ;; Find the current contrast
            (vla-Regen doc :vlax-true)
            (alert (strcat "The Contrast is currently set to: " (rtos (vla-get-Contrast raster) 2)))
    
            ;; Change the contrast to 5
            (vla-put-Contrast raster 5)
            (vla-Regen doc :vlax-true)
            (alert (strcat "The Contrast is now set to: " (rtos (vla-get-Contrast raster) 2)))	  
	)
        (alert (strcat imageName " could not be found."))
    )
)