访问对象层次结构
访问对象层次结构
访问 Application 对象
用户可以直接或通过自己定义的变量来引用对象。要直接引用对象，请将对象包含在调用层次结构中。例如，下列语句在模型空间中添加一条直线。请注意，层次结构从 ThisDrawing 开始，再转到 ModelSpace 对象，然后调用 AddLine 方法：
Dim startPoint(0 To 2) As Double, endPoint(0 To 2) As Double
Dim LineObj as AcadLine
startPoint(0) = 0: startPoint(1) = 0: startPoint(2) = 0
endPoint(0) = 30: endPoint(1) = 20: endPoint(2) = 0
Set LineObj = ThisDrawing.ModelSpace.AddLine(startPoint,endPoint)
要通过用户定义的变量引用对象，请首先将变量定义为所需类型，然后设置为相应的对象。例如，以下代码定义类型为 AcadModelSpace 的变量 (moSpace) 并将其设置为等于当前的模型空间：
Dim moSpace As AcadModelSpace
Set moSpace = ThisDrawing.ModelSpace
Dim startPoint(0 To 2) As Double, endPoint(0 To 2) As Double
Dim LineObj as AcadLine
startPoint(0) = 0: startPoint(1) = 0: startPoint(2) = 0
endPoint(0) = 30: endPoint(1) = 20: endPoint(2) = 0
Set LineObj = moSpace.AddLine(startPoint,endPoint)
本例返回模型空间中的第一个图元对象，类似的代码还可以用来检索图纸空间中的第一个图元。注意：可以将所有的图形对象定义为 AcadEntity 对象：
Sub Ch2_FindFirstEntity()
' 本例返回模型空间中的第一个图元
On Error Resume Next
Dim entity As AcadEntity
If ThisDrawing.ModelSpace.count <> 0 Then
Set entity = ThisDrawing.ModelSpace.Item(0)
MsgBox entity.ObjectName + _
" is the first entity in model space."
否则
MsgBox "There are no objects in model space."
End If
End Sub