主题：代码问题

 这个意思？

If e.DataCol.Name = "汇总" AndAlso e.DataRow("汇总") = True Then
    Dim dn As DataRow = DataTables("收支汇总表").Find("合同或协议号 = '" & e.DataRow("合同或协议号") & "'")
    If dn IsNot Nothing Then '如果找到相同的合同或协议号
        MessageBox.Show("收支汇总表已经存在相同合同或协议号的行!")
       
    Else
        Dim nma() As String = { "贷款主体","贷款银行","合同或协议名称","合同或协议号","贷款项目名称","FKJE","贷款额度" } 'A表数据来源列
        Dim nmb() As String = { "主体单位","款项来源单位","款项来源名称或类别","记录编号","贷款项目名称","到位资金","贷款或申请额度" } 'B表数据接收列
        Dim dr As DataRow = DataTables("收支汇总表").AddNew
        For i As Integer = 0 To nma.Length - 1
            dr(nmb(i)) = e.DataRow(nma(i))
        Next
    End If
End If

呃，那你重置汇总列。

 只要列名写正确，就不会有问题。而且，是重置汇总列啊

If e.DataCol.Name = "汇总" AndAlso e.DataRow("汇总") = True Then
    Dim dn As DataRow = DataTables("收支汇总表").Find("合同或协议号 = '" & e.DataRow("合同或协议号") & "'")
    If dn IsNot Nothing Then '如果找到相同的合同或协议号
        MessageBox.Show("收支汇总表已经存在相同合同或协议号的行!")
       
    Else
        Dim nma() As String = { "贷款主体","贷款银行","合同或协议名称","合同或协议号","贷款项目名称","FKJE","贷款额度" } 'A表数据来源列
        Dim nmb() As String = { "主体单位","款项来源单位","款项来源名称或类别","记录编号","贷款项目名称","到位资金","贷款或申请额度" } 'B表数据接收列
        Dim dr As DataRow = DataTables("收支汇总表").AddNew
        For i As Integer = 0 To nma.Length - 1
            dr(nmb(i)) = e.DataRow(nma(i))
        Next
    End If
End If