主题：这个代码如果是1月份 找上月的 怎么修改?

Dim y As Integer = Date.Today.Year

Dim m As Integer = Date.Today.Month

Dim dt1 As New Date(y, m-1, 1)

Dim dt2 As New Date(y, m, Date.DaysInMonth(y, m)) '获取本月的最后一天

Dim Filter As String

Filter = "日期 >= #" & dt1 & "# And 日期 <= #" & dt2 & "#"

Output.Show(Filter)