为什么用JIG类预览块的时候很不清晰

lihezhou · 发表于 2015-1-21 19:45:00

为什么用JIG类预览块的时候很不清晰。代码如下:
'旋转预览--镜像预览
Public Class False_Rotation
Inherits DrawJig
Public BasePt As Point3d
Public EntCopy() As Entity '复制出来预览的对象
Private BAngle As Single
Private AngleScale As Integer = 1
' WorldDraw函数用于刷新屏幕上显示的图形.
Protected Overrides Function WorldDraw(ByVal draw As WorldDraw) As Boolean
      On Error Resume Next
      For i = 0 To EntCopy.Length - 1
         draw.Geometry.Draw(EntCopy(i))
      Next
      Return True
End Function
Protected Overrides Function Sampler(ByVal prompts As JigPrompts) As SamplerStatus
      On Error Resume Next
      ' 定义一个角度拖动交互类.
      Sampler = Nothing
      Dim optJigAngle1 As New JigPromptAngleOptions(vbCrLf & "请指定旋转角度")
      ' 设置拖拽的光标类型.
      optJigAngle1.Cursor = CursorType.RubberBand
      ' 设置拖动光标基点.
      optJigAngle1.BasePoint = BasePt
      optJigAngle1.UseBasePoint = True
      ' 用AcquireAngle函数得到用户输入的角度值.
      Dim resJigAngle1 As PromptDoubleResult = prompts.AcquireAngle(optJigAngle1)
      If BAngle  resJigAngle1.Value Then
         ' 保存当前角度值.
         For i = 0 To EntCopy.Length - 1
            EntCopy(i).TransformBy(Matrix3d.Rotation((resJigAngle1.Value - BAngle) * AngleScale, Vector3d.ZAxis, BasePt))
         Next
         BAngle = resJigAngle1.Value
         Return SamplerStatus.OK
      Else
         Return SamplerStatus.NoChange
      End If
End Function
End Class
调用
         Dim Ent(0) As Entity
         Ent(0) = InserBlock
         Dim QJI As New False_Move
         QJI.EntCopy = Ent
         QJI.BasePt = New Point3d()
         QJI.CurrPt = New Point3d()
         Dim jigRes As PromptResult = AcDocEd.Drag(QJI)‘移动预览没有问题
         If jigRes.Status = PromptStatus.OK Then
            Dim RJI As New False_Rotation'旋转预览就很闪烁。预览的对象不全
            RJI.BasePt = QJI.CurrPt
            RJI.EntCopy = Ent
            QJI = Nothing
            jigRes = AcDocEd.Drag(RJI)
            If jigRes.Status = PromptStatus.OK Then
                  ModelSpace.AppendEntity(Ent(0))
            End If
         End If