Question

我想通过询问MsgBoxStyle.YesNo删除指定目录中的文件，如果这些文件不存在，则显示msgbox。

我尝试了以下代码，但只打开了MsgBoxStyle.YesNo，没有其他事情发生。

    Dim di As IO.DirectoryInfo = New IO.DirectoryInfo(Application.StartupPath & "\..\..\1.txt")
    Dim di1 As IO.DirectoryInfo = New IO.DirectoryInfo(Application.StartupPath & "\..\..\2.txt")
    Dim di2 As IO.DirectoryInfo = New IO.DirectoryInfo(Application.StartupPath & "\..\..\3.txt")

    If MsgBox("Are you sure?", MsgBoxStyle.Exclamation + MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then
    ElseIf di.Exists And di1.Exists And di2.Exists Then
        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\1.txt")
        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\2.txt")
        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\3.txt")
        MsgBox("Done!", MsgBoxStyle.Exclamation)
    Else
        MsgBox("No file found!", MsgBoxStyle.Exclamation)
    End If

我也试过以下代码。但是这次如果文件不存在，应用程序崩溃。

Dim di As IO.DirectoryInfo = New IO.DirectoryInfo(Application.StartupPath & "\..\..\1.txt")
Dim di1 As IO.DirectoryInfo = New IO.DirectoryInfo(Application.StartupPath & "\..\..\2.txt")
Dim di2 As IO.DirectoryInfo = New IO.DirectoryInfo(Application.StartupPath & "\..\..\3.txt")

If di.Exists And di1.Exists And di2.Exists Then
ElseIf MsgBox("Are you sure?", MsgBoxStyle.Exclamation + MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then

    My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\1.txt")
    My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\2.txt")
    My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\3.txt")
    MsgBox("Done!", MsgBoxStyle.Exclamation)
Else
    MsgBox("No file found!", MsgBoxStyle.Exclamation)
End If

我做错了什么？

Answer 1

在这两个解决方案中，你错误地使用了'ElseIf'.corrct方式来做到这一点：

解决方案1：

If MsgBox("Are you sure?", MsgBoxStyle.Exclamation + MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then
    If di.Exists And di1.Exists And di2.Exists Then
        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\1.txt")
        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\2.txt")
        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\3.txt")
        MsgBox("Done!", MsgBoxStyle.Exclamation)
    Else
        MsgBox("No file found!", MsgBoxStyle.Exclamation)
    End If
End If

解决方案2：

  If di.Exists And di1.Exists And di2.Exists Then
    If MsgBox("Are you sure?", MsgBoxStyle.Exclamation + MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then

        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\1.txt")
        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\2.txt")
        My.Computer.FileSystem.DeleteFile(Application.StartupPath & "\..\..\3.txt")
        MsgBox("Done!", MsgBoxStyle.Exclamation)
    Else
        MsgBox("No file found!", MsgBoxStyle.Exclamation)
End If

删除指定的路径文件，如果没有文件则显示msgbox

1 个答案: