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Question

以下是我正在尝试的代码：

If txtMonths >= 1 And txtMonths <= 6 Then
    additionalDiscount = 0

Answer 1

intMonths是TextBox，而非int，因此您无法将其用作int。您必须提取其文本值并首先将其转换为int：

Dim intMonthsVal As Integer = Integer.Parse(txtMonths.Text)
If intMonthsVal >= 1 AndAlso intMonthsVal <= 6 Then
    additionalDiscount = 0
End If