Question

我正在使用一个TRY Catch Block而且我得到的错误并期望在这里落地：

       Throw New System.Exception("Copy of FileZilla file failed: " & ex.Message)

我得到的输出按以下顺序：

创建FileZilla文件夹失败：创建FileZilla文件失败： FileZilla文件的副本失败：拒绝访问路径“C：\ Program Files（x86）\ FileZilla Server”。

为什么它会击中另外2并显示它们？

        Dim sourceFile As FileInfo = New FileInfo(strSourcePathAndFile)

        Try
            ' Create the folder if it does not exist.
            If Not Directory.Exists(strDestinationFolder) Then
                Directory.CreateDirectory(strDestinationFolder)
            End If

            Try
                ' Create the file if it does not exist.
                If Not File.Exists(strDestinationPathAndFile) Then
                    File.Create(strDestinationPathAndFile)
                End If
                Try
                    ' Copy the source file to the destination file and overwrite it.
                    sourceFile.CopyTo(strDestinationPathAndFile, True)
                Catch ioex As IOException
                    Throw New System.Exception("Copy of FileZilla file I/O failed: " & ioex.Message)
                Catch ex As Exception
                    Throw New System.Exception("Copy of FileZilla file failed: " & ex.Message)
                End Try
            Catch ex As Exception
                Throw New System.Exception("Create of FileZilla file failed: " & ex.Message)
            End Try
        Catch ex As Exception
            Throw New System.Exception("Create of FileZilla folder failed: " & ex.Message)
        End Try
    End Sub

...问候

Answer 1

因为你抛出新的异常，它被另一个Catch块捕获，冲洗和放大重复。

你的外部处理程序处理通用的异常类型，也许这就是你要求的。将其更改为处理其他类型的异常。或者只需要一个Try ... Catch block。

Answer 2

你正在捕捉三个抛出异常，因为你有三个级别的Try ... Catch。

你还有什么期待？

最内部的Catch引发了一个新的异常。这自然被中间Catch捕获，然后抛出一个新的异常，它被最外层的捕获所捕获。

Answer 3

那是因为您正在使用嵌套的try..catch块。错误在几个级别为catch。您可以尝试以下方法：

Dim sourceFile As FileInfo = New FileInfo(strSourcePathAndFile)
Dim error as String

    Try
        ' Create the folder if it does not exist.
        If Not Directory.Exists(strDestinationFolder) Then
            Directory.CreateDirectory(strDestinationFolder)
        End If

        Try
            ' Create the file if it does not exist.
            If Not File.Exists(strDestinationPathAndFile) Then
                File.Create(strDestinationPathAndFile)
            End If
            Try
                ' Copy the source file to the destination file and overwrite it.
                sourceFile.CopyTo(strDestinationPathAndFile, True)

            Catch ioex As IOException

                If String.IsNullOrEmpty(error) then _
                error = string.concat("Copy of FileZilla file I/O failed: ", ioex.Message)
            Catch ex As Exception

                If String.IsNullOrEmpty(error) then _
                error = string.concat("Copy of FileZilla file failed: ", ex.Message)
            End Try

        Catch ex As Exception

            If String.IsNullOrEmpty(error) then _
            error = string.concat("Create of FileZilla file failed: ", ex.Message)
        End Try

    Catch ex As Exception
        Throw New System.Exception(string.concat(error, ex.Message)
    End Try

End Sub

尝试Catch显示超出我的预期

3 个答案: