30天后获取datetimepicker值

Question

我有记录用户付款的程序，用户可以获得30天的手机信用，我需要做的是在datetimepiker选择1-1-2015我希望在这一天之后获得30天所以价值将是1 -2-2015。 我怎么能这样做？

      Dim Day = DateTimePicker1.Value.Day
    Dim Month = DateTimePicker1.Value.Month
    Dim Year = DateTimePicker1.Value.Year

    Dim d As Integer = Day + 30
    Dim m As Integer
    Dim dd As Integer
    Dim mm As Integer

    If d > 30 Then
        dd = d - 30
        m = Month + 1
    End If
    If m > 12 Then
        mm = Month - 12
        Year = Year + 1

        TextBox1.Text = dd & "-" & mm & "-" & Year
    Else
        TextBox1.Text = dd & "-" & m & "-" & Year
    End If

Answer 1

不应使用Integers进行计算，而应使用DateTime.AddDays：

Dim dt As Date = DateTimePicker1.Value
Dim thirtyDaysAfter As Date = dt.AddDays(30)
TextBox1.Text = thirtyDaysAfter.ToString("dd-MM-yyyy") 

如果你想要下个月，你可以使用dt.AddMonths(1)。