Visual Basic/错误处理

Visual Basic 中的错误处理，概述

• On Error Goto <Label>
• On Error Goto 0
• On Error Resume Next
• If Err.Number = 0
• If Err.Number <> 0
• Resume
• Resume <Label>
• Resume Next
• Err.Description
• Err.Raise <Number>

禁止错误并使用非零错误号检测错误：

Set MyCollection = New Collection
MyCollection.Add "Item", "Item"
On Error Resume Next
MyCollection.Add "Item", "Item" 'This result in an error
MyErrNumber = Err.Number
On Error Goto 0 'Restore the absence of error handling
If MyErrNumber <> 0 Then
  'Error occurred
  MsgBox "Item already present in the collection."
End If

创建错误处理程序：

Sub Test()
  On Error Goto ErrorHandler
  ...
  Exit Sub

ErrorHandler:
  ...
End Sub

创建区分每个错误号的错误处理程序：

Sub Test()
  On Error Goto ErrorHandler
  ...
  Exit Sub

ErrorHandler:
  Select Case Err.Number
  Case 0
    'No error
  Case 5
    '...
  Case Else
    '...
  End Select
End Sub

另请参阅 Visual Basic/Effective Programming#Errors_and_Exceptions 和 Visual Basic/Coding_Standards#Error_Handling。