主题：System.IndexOutOfRangeException: 索引超出了数组界限

System.Reflection.TargetInvocationException: 调用的目标发生了异常。 ---> System.IndexOutOfRangeException: 索引超出了数组界限。
麻烦老师帮忙看看   主要是在台账中如果没有编号  就会出现这个……如果已经有了类似bazbdy001的编号就不会出现

当前代码：

Dim lb As String = dr("分类代码")
Dim idx As Integer
Dim cmd As New S QLC ommand
cmd.Con nect io nNa me = "主数据源"
cmd.CommandText = "Se lect * From 台账 where 分类代码 = '" & lb & "' And [_Identify] <>''"
Dim dt As DataTable = cmd.ExecuteReader()
Dim dr1 As DataRow = dt.DataRows(dt.DataRows.Count - 1) '获得最后一行
output.show(dr1("_Identify"))
If dr1("编号").StartsWith("BZZB" & lb) = False '如果单据编号前缀不符
    cmd.CommandText = "sele ct Max(编号) from 台账 where 分类代码 = '" & lb & "' And [_Identify] <> " & dr1("_Identify")
    Dim max As String
    max = cmd.ExecuteScalar()
    output.show(max)
    If max > "" Then '如果存在最大编号
        idx = CInt(max.Substring(6,3)) + 1 '获得最大编号的后三位顺序号,并加1
    Else
        idx = 1 '否则顺序号等于1
    End If
    dr("编号")=("BAZB" & lb & Format(idx,"000"))
    dr.Save
End If

运行提示：

错误的事件名称项目,HttpRequest
System.Reflection.TargetInvocationException: 调用的目标发生了异常。 ---> System.IndexOutOfRangeException: 索引超出了数组界限。
   在 eWebSer.form673_save_Ajax(Request rq)
   --- 内部异常堆栈跟踪的结尾 ---
   在 Microsoft.VisualBasic.CompilerServices.Symbols.Container.InvokeMethod(Method TargetProcedure, Object[] Arguments, Boolean[] CopyBack, BindingFlags Flags)
   在 Microsoft.VisualBasic.CompilerServices.NewLateBinding.CallMethod(Container BaseReference, String MethodName, Object[] Arguments, String[] ArgumentNames, Type[] TypeArguments, Boolean[] CopyBack, BindingFlags InvocationFlags, Boolean ReportErrors, ResolutionFailure& Failure)
   在 Microsoft.VisualBasic.CompilerServices.NewLateBinding.ObjectLateCall(Object Instance, Type Type, String MemberName, Object[] Arguments, String[] ArgumentNames, Type[] TypeArguments, Boolean[] CopyBack, Boolean IgnoreReturn)
   在 Microsoft.VisualBasic.CompilerServices.NewLateBinding.LateCall(Object Instance, Type Type, String MemberName, Object[] Arguments, String[] ArgumentNames, Type[] TypeArguments, Boolean[] CopyBack, Boolean IgnoreReturn)
   在 UserCode.HttpRequest(RequestEventArgs e)
2022-12-15 09:00:37

Dim lb As String = dr("分类代码")
    Dim idx As Integer
    Dim cmd As New SQLCommand
    cmd.Conn ecti onNa me = "主数据源"
    cmd.CommandText = "Se lect * From 台账 where 分类代码 = '" & lb & "' And [_Identify] <>''"
    Dim dt As DataTable = cmd.ExecuteReader()
    Dim dr1 As DataRow
    If dr1 IsNot Nothing Then    如果找到行  那就获取最大编号
        dr1= dt.DataRows(dt.DataRows.Count - 1) '获得最后一行
        output.show(dr1("_Identify"))
        cmd.CommandText = "sel ect Max(编号) from 台账 where 分类代码 = '" & lb & "' And [_Identify] <> " & dr1("_Identify")
        Dim max As String
        max = cmd.ExecuteScalar()
        If max > "" Then '如果存在最大编号
            idx = CInt(max.Substring(max.length - 3)) + 1  '获得最大编号的后三位顺序号,并加1
        Else
            idx = 1 '否则顺序号等于1
        End If
        dr("编号")=(lb & Format(idx,"000"))
    Else   如果找不到行  那就直接定义为1 并开始编号
        idx = 1 '否则顺序号等于1
        dr("编号")=(lb & Format(idx,"000"))
    End If

继续麻烦老师一下    我当前得到的编号永远都是001

Dim dr As DataRow = rq.result '返回当前保存的数据行,可再处理数据
If dr IsNot Nothing Then
    Dim lb As String = dr("分类代码")
    Dim idx As Integer
    Dim cmd As New SQ LC ommand
    cmd.Conn ecti onN ame = "主数据源"
    cmd.CommandText = "Se lect * From 台账 where 分类代码 = '" & lb & "' And [_Identify] <>''"
    Dim dt As DataTable = cmd.ExecuteReader()
    Dim dr1 As DataRow
 If dr1 IsNot Nothing Then
        dr1= dt.DataRows(dt.DataRows.Count - 1) '获得最后一行
        output.show(dr1("_Identify"))
        cmd.CommandText = "sele ct Max(编号) from 台账 where 分类代码 = '" & lb & "' And [_Identify] <> " & dr1("_Identify")
        Dim max As String
        max = cmd.ExecuteScalar()
        If max > "" Then '如果存在最大编号
            idx = CInt(max.Substring(max.length - 3)) + 1  '获得最大编号的后三位顺序号,并加1
        Else
            idx = 1 '否则顺序号等于1
        End If
        dr("编号")=lb & Format(idx,"000")
    Else
        idx = 1 '否则顺序号等于1
        dr("编号")=lb & Format(idx,"000")
    End If
    dr.Save
End If

老师保存了的   也是一样的不递增……

经核查   代码运行后   对应的第一个编号是保存到了数据库中的编号字段的

还得麻烦老师 指导下：或者是将下述代码  用其他方式实现类似效果

Dim dr As DataRow = rq.result '返回当前保存的数据行,可再处理数据
If dr IsNot Nothing Then
    Dim lb As String = dr("分类代码")
    Dim idx As Integer
    Dim cmd As New SQ LC ommand
    cmd.Conn ecti onN ame = "主数据源"
    cmd.CommandText = "Se lect * From 台账 where 分类代码 = '" & lb & "' And [_Identify] <>''"
    Dim dt As DataTable = cmd.ExecuteReader()
    Dim dr1 As DataRow
 If dr1 IsNot Nothing Then
        dr1= dt.DataRows(dt.DataRows.Count - 1) '获得最后一行
        output.show(dr1("_Identify"))
        cmd.CommandText = "sele ct Max(编号) from 台账 where 分类代码 = '" & lb & "' And [_Identify] <> " & dr1("_Identify")
        Dim max As String
        max = cmd.ExecuteScalar()
        If max > "" Then '如果存在最大编号
            idx = CInt(max.Substring(max.length - 3)) + 1  '获得最大编号的后三位顺序号,并加1
        Else
            idx = 1 '否则顺序号等于1
        End If
        dr("编号")=lb & Format(idx,"000")
    Else
        idx = 1 '否则顺序号等于1
        dr("编号")=lb & Format(idx,"000")
    End If
    dr.Save
End If

当前代码如下：

Public Sub form673_save_Ajax(rq As Request)
Me.tablesave(rq) '保存数据表
Dim dr As DataRow = rq.result '返回当前保存的数据行,可再处理数据
If dr IsNot Nothing Then
    Dim lb As String = dr("分类代码")
    Dim idx As Integer
    Dim cmd As New SQLCommand
    cmd.Conn ect ion Name = "主数据源"
   
    cmd.CommandText = "Se lect * From 办案装备_管理台账 where 分类代码 = '" & lb & "' And [_Identify] <>''"
    Dim dt As DataTable = cmd.ExecuteReader()
    If dt.DataRows.Count>1 Then
        Dim dr1 As DataRow
        dr1= dt.DataRows(dt.DataRows.Count - 1) '获得最后一行
        If dr1 IsNot Nothing Then
            output.show(dr1("_Identify"))
            cmd.CommandText = "sele ct Max(编号) from 办案装备_管理台账 where 分类代码 = '" & lb & "' And [_Identify] <> " & dr1("_Identify") 
            Dim max As String
            max = cmd.ExecuteScalar()
            If max > "" Then '如果存在最大编号
                idx = CInt(max.Substring(max.length - 3)) + 1  '获得最大编号的后三位顺序号,并加1
            Else
                idx = 1 '否则顺序号等于1
            End If
        Else
            idx = 1 '否则顺序号等于1
        End If
        dr("编号")=lb & Format(idx,"000")
        dr.Save
    End If
End If
rq.e.WriteString(rq.msg.ToString)
End Sub

 运行后出现两个重号后会新增一个号     

此主题相关图片如下：11.png

上述问题有没有办法解决呢？或者有没有直接SQL语句可以直接实现对应的编号按类别不同递增呢？

代码二：

Public Sub form673_save_Ajax(rq As Request)
Me.tablesave(rq) '保存数据表
Dim dr As DataRow = rq.result '返回当前保存的数据行,可再处理数据
If dr IsNot Nothing Then
    Dim lb As String = dr("分类代码")
    Dim idx As Integer
    Dim cmd As N ew S QLCommand
    cmd.Conne ctio nName = "主数据源"
    cmd.CommandText = "Sele ct * From 办案装备_管理台账 where 分类代码 = '" & lb & "' "
    Dim dt As DataTable = cmd.ExecuteReader()
    If dt.DataRows.Count>1 Then
        cmd.CommandText = "sel ect Max(编号) from 办案装备_管理台账 where 分类代码 = '" & lb & "'"
        Dim max As String
        max = cmd.ExecuteScalar()
        If max > "" Then '如果存在最大编号
            idx = CInt(max.Substring(max.length - 3)) + 1  '获得最大编号的后三位顺序号,并加1
        Else
            idx = 1 '否则顺序号等于1
        End If
    Else
        idx = 1 '否则顺序号等于1
    End If
    If dr("编号")<> Nothing Then
    Else
        dr("编号")=lb & Format(idx,"000")
    End If
    dr.Save
End If
rq.e.WriteString(rq.msg.ToString)
End Sub