Msgbox YesNo误差

Question

我得到以下错误消息:表达式是一个值，因此不能成为分配的目标。

对于此代码

MsgBox("Do you really wish to delete " & txtLayerDelete.Text & "?", MsgBoxStyle.YesNo) = MsgBoxResult.Yes

txtLayerDelete在UserControl上。

Answer 1

您已经尝试分配MsgBox，并且没有使用该方法的返回值。

MsgBox("Do you really wish to delete " & txtLayerDelete.Text & "?", MsgBoxStyle.YesNo)

如果要向用户显示消息框，此方法将返回您应该使用的MsgBoxResult对象，如下所示。

Dim delete =  MsgBox("Do you really wish to delete " & txtLayerDelete.Text & "?", MsgBoxStyle.YesNo)

If delete = MsgBoxResult.Yes Then
  'Your logic
End If 

您只需添加一个If语句就可以了：

If MsgBox("Do you really wish to delete?", MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then

End If

另外需要注意的是，MsgBox函数似乎已经过时，您应该尝试使用MessageBox.Show。

Dim delete = MessageBox.Show("Should this item be deleted", "Form Title", MessageBoxButtons.YesNo)

If delete = DialogResult.Yes Then

End If

Answer 2

这边试试。注意，MsgBox和MessageBox返回的结果是枚举值。MsgBox被MessageBox取代

    Dim result As DialogResult = MessageBox.Show("Do you really wish to delete " & txtLayerDelete.Text & "?", , MessageBoxButtons.YesNo)
    If result = Windows.Forms.DialogResult.Yes Then

    End If

Answer 3

你没有使用返回值的方法，我的朋友。

它应该是：

`Dim dialogDel = MsgBox("Do you really wish to delete " & txtLayerDelete.Text & "?", MsgBoxStyle.YesNo)`

If dialogDel = DialogResult.Yes Then
 'Yes code.
Else
 'No code
End If

欢迎:)