Dim cmb As WinForm.ComboBox
cmb = Forms("窗口1").Controls("ComboBox1")
cmb.ComboList = DataTables("表a").GetComboListString("a列") 绑定组合框A
然后再组合框A的SelectedIndexChanged事件写下面代码
Dim cm As WinForm.ComboBox = e.Form.Controls("ComboBox1")
Dim cb As WinForm.ComboBox
cb = Forms("窗口1").Controls("ComboBox2")
cb.ComboList = DataTables("表a").GetComboListString("b列","[a列] ='" & cm.Text & "'")