检查 VBA 中的当前错误处理

Question

在 VBA 中，错误处理由 on error 语句完成。

我想暂时更改错误处理，然后再回到以前的行为。如何检查当前的错误处理并将其存储在变量中（我在引用中找不到任何内容）？

'set the error handling to s.th. "on error... "
'some code with the regular error handling

'change the error handling to "on error ..." (regardless of what it was before)
'some code with the new error handling

'change back to the previous error handling
'some code with the regular error handling

背景：我需要对 Variant 数组进行is nothing 检查以排除使用空对象索引，但将is nothing 应用于包含值的数组索引会引发异常，所以我暂时想更改对on error resume next 的错误处理。最终使用不同的方法解决了这个问题，但我仍然想知道我是否可以在运行时以某种方式确定当前的错误处理Here's the question and answer to my original problem。

编辑：我知道我可以手动检查我以前的代码以找出使用了哪种类型的错误处理。但是我想避免这种情况（以节省时间）。

我想作为一种解决方法，我可以设置一个带有状态的附加变量，然后我可以检查当前状态，尽管这会导致相当多的开销。像这样的：

Dim errorHandling as String

errorHandling = "resumeNext"
on error resume next
'some code

'changing the error handling temp.
'some other code

'changing the error handling to it's previous state
if errorhandling = "resumeNext" then
   On Error Resume Next
elseif errorhandling = "GoToErrorhandler" then
   On Error GoTo errorhandler
End If

'Rest of the code

Answer 1

读取/写入数组

Option Explicit

Sub ReadWriteArrayExample()

    Dim myArray() As Variant: ReDim myArray(1 To 10)
    
    Dim i As Long
    Dim n As Long
    
    ' Fill the array.
    For i = 1 To 10
        n = Application.RandBetween(0, 1)
        If n = 1 Then ' write a random number between 1 and 10 inclusive
            myArray(i) = Application.RandBetween(1, 10)
        'Else ' "n = 0"; leave the element as-is i.e. 'Empty';do nothing
        End If
    Next i
    
    ' Debug.Print the result.
    Debug.Print "Position", "Value"
    For i = 1 To 10
        If Not IsEmpty(myArray(i)) Then ' write the index and the value
            Debug.Print i, myArray(i)
        'Else ' is empty; do nothing
        End If
    Next i

End Sub

错误处理

Sub ErrorHandling()

    Const ProcName As String = "ErrorHandling"
    On Error GoTo ClearError ' enable error trapping

    ' Some code

    On Error Resume Next ' defer error trapping
        ' Some tricky code
    On Error GoTo ClearError ' re-enable error trapping

    ' Some Code

ProcExit:
    Exit Sub
ClearError:
    Debug.Print "'" & ProcName & "' Run-time error '" _
        & Err.Number & "':" & vbLf & "    " & Err.Description
    Resume ProcExit
    
End Sub