VBA OnError异常处理不起作用

Question

我在我的VBA中有以下示例代码。每当我面对系统相关的错误，我想显示我自己的错误消息。但下面的代码不起作用。

VBA告诉

类型不匹配

我想

你好你的日期是无效的

我的代码

Sub good() 

Dim date_ As Date 
date_ = "hello" 

On Error GoTo Err1: 

Err1: 
    MsgBox "Hello your date is invalid" 
    ' more code 

End Sub 

Answer 1

您需要在之前将On Error语句发生错误，通常在过程的最初阶段。将On Error语句看作一条指示，告诉VBA如何处理稍后在过程中遇到的任何错误。

Sub good() 

On Error GoTo Err1 

Dim date_ As Date 
date_ = "hello" 

Exit Sub 'Make sure you include this so successful executions 
     'don't continue into the error block. 

Err1: 
    Select Case Err.Number 
     Case 101 'Not the actual error number! 
     MsgBox "Hello your date is invalid" 
     Case 102 'Not the actual error number! 
     MsgBox "Something else bad happened!" 
     Case Else 
     MsgBox "I don't know what happened - unexpected error!" 
    End Select 
    ' more code 

End Sub 

Answer 2

您需要将On Error声明放在错误之前！

另外，不要在最后忘记了Exit Sub，否则你的程序将始终运行错误代码：

Sub good() 
    Dim date_ As Date 

    On Error GoTo Err1: 
    date_ = "hello" 

    On Error Goto 0 'goes back to default, i.e. show debugger 
    Exit Sub 

Err1: 
    MsgBox "Hello your date is invalid" 
    ' more code 

End Sub 

或者，您也可以做到这一点

Sub good() 
    Dim date_ As Date 

    On Error Resume Next 
    date_ = "hello" 
    If Err.Number <> 0 Then 
     MsgBox "Wrong type" 
     Err.Clear 
     Exit Sub 
    End If 

    On Error Goto 0 

    ' more code 

End Sub 

这种方法可以重复捕捉个人错误...