主题：上月的最后一天 ,及上一个月的第一天 表达式该怎么写呢?

Dim d As Date = e.DataRow("日期")
        Dim y As Integer = d.Year
        Dim m As Integer = d.Month
        Dim Days As Integer = Date.DaysInMonth(y,m)
        Dim fd As Date = New Date(y,m,1) '获得该月的第一天
        Dim ld As Date = New Date(y,m,Days)

参考下