Dim lst As new List(of Date)
Dim d As Date = Date.Today.AddMonths(-1)
Dim nd As Date = d
Do While d < Date.Today
lst.Add(d)
d = d.AddDays(1)
Loop
For Each s As String In DataTables("表A").GetValues("日期","日期 >= #" & nd & "#")
lst.Remove(cDate(s))
Next
Dim lst2 As new List(of String)
For Each d In lst
lst2.Add(Format(d,"yyyy-MM-dd"))
Next
Dim cmb As WinForm.ComboBox
cmb = Forms("窗口1").Controls("ComboBox1")
cmb.ComboList = String.Join("|",lst2.ToArray)