我知道是e.Form.Controls("TextBox2").text为空造成报错的，无论红色标注代码写成If e.Form.Controls("ComboBox3").text IsNot Nothing And e.Sender.value IsNot Nothing then,还是下面的三个控件都不为行，其实，第三个条件是前面二个条件不为空自动生成的，问题都没解决。
'以这代码为准:
e.Sender.WriteValue()
Dim yzdh As WinForm.TextBox = e.Form.Controls("dh")'dh是单号控件
Dim di As String = yzdh.Value 'di单号控件中的变量
Dim d As Date = e.Sender.Value
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) '获得该月的最后一天
Dim Max0 As String
Dim idx As Integer
Dim flt As String = "[字号] = '" & (e.Form.Controls("TextBox2").text).SubString(0,2) & "' And [日期] >= #" & fd & "# And [日期] <= #" & ld & "#"
If e.Form.Controls("ComboBox3").text IsNot Nothing And e.Sender.value IsNot Nothing And e.Form.Controls("TextBox2").text IsNot Nothing Then
Dim dts As Integer = DataTables("财务数据源").Compute("Count([会计科目])","[字号] = '" & e.Form.Controls("TextBox2").text & "' And [日期] >= #" & fd & "# And [日期] <= #" & ld & "# And [凭证号] = '" & di & "'")
If dts = 0 Then
Max0 = DataTables("财务数据源").Compute("Max(凭证号)",flt) '取得该月的相同工程代码的最大单据编号
If Max0 > "" Then '如果存在最大单据编号
idx = CInt(Max0) + 1 '获得最大单据编号的后四位顺序号,并加1
Else
idx = 1 '否则顺序号等于1
End If
di = idx
yzdh.Value = di
End If
Else
yzdh.Value = Nothing
End If
[此贴子已经被作者于2021/6/8 13:46:50编辑过]
加好友 
发短信
Post By：2021/6/4 21:58:00 [显示全部帖子]
此主题相关图片如下：qq图片20210604204615.png
