主题：and 和andalso会导致不一样的结果？

 Dim dr As DataRow
    dr=DataTables("Order").Find("planvsactual = 'Actual' and so_no ='" & e.node.Name & "'")
    If dr IsNot Nothing Then
        For Each c As WinForm.Control In e.Form.Controls
            If Typeof c Is WinForm.CheckBox Then '判断控件是否是文本框
                Dim t As WinForm.CheckBox = c '使用特定类型的变量引用控件
                For Each Cl As DataCol In DataTables("Order").DataCols
                    If cl.name = t.name And dr(cl.name) <> #1/1/1 0:00:00# Then
                        t.Checked=True
                        MessageBox.Show(cl.name & t.name & dr(cl.name))
                    End If
                Next
            End If
        Next
    End If

上面这个代码会出错。显示：从字符串“1232ff”到类型“Date”的转换无效。

下面这个代码就运行正常

 Dim dr As DataRow
    dr=DataTables("Order").Find("planvsactual = 'Actual' and so_no ='" & e.node.Name & "'")
    If dr IsNot Nothing Then
        For Each c As WinForm.Control In e.Form.Controls
            If Typeof c Is WinForm.CheckBox Then '判断控件是否是文本框
                Dim t As WinForm.CheckBox = c '使用特定类型的变量引用控件
                For Each Cl As DataCol In DataTables("Order").DataCols
                    If cl.name = t.name Andalso dr(cl.name) <> #1/1/1 0:00:00# Then
                        t.Checked=True
                        MessageBox.Show(cl.name & t.name & dr(cl.name))
                    End If
                Next
            End If
        Next
    End If

有人知道为什么么？是“=”运行的先后顺序么？

括起来试试

恩。夸起来有用