主题：如何在表C中找出对应的多行并自动增加到表A中

DataColChanged

Select Case e.DataCol.name
    Case "报料阶段", "使用工艺名称"
        If e.DataRow.isnull("报料阶段")= False AndAlso e.DataRow.isnull("使用工艺名称") = False Then
            Dim Cols1() As String = {"来源列一","来源列二","来源列三"}
            Dim Cols2() As String = {"接收列一","接收列二","接收列三"}
            Dim drs As List(Of DataRow) = DataTables("表B").Select("报料阶段 = '" & e.DataRow("报料阶段") & "' and 工艺名称 = '" & e.DataRow("使用工艺名称") & "'")
            systemready = False
            For i As Integer = 0 To drs.count-1
                Dim dr2 As DataRow
                If i = 0 Then
                    dr2 = e.DataRow
                Else
                    dr2 = e.DataTable.addnew
                End If
                For j As Integer = 0 To Cols1.Length -1
                    dr2(Cols2(j)) = e.DataRow(Cols1(j))
                Next
               
                dr2("报料阶段") = e.DataRow("报料阶段")
                dr2("使用工艺名称") = e.DataRow("使用工艺名称")
               
            Next
            systemready = True
        End If
End Select

是不是你表名写错了？要写表C的名字

Dim drs As List(Of DataRow) = DataTables("工艺配方").Select("报料阶段 = '" & e.DataRow("报料阶段") & "' and 工艺名称 = '" & e.DataRow("使用工艺名称") & "'")

如果还不行，单独做个小例子上传上来测试。

新建一个项目，把你的表A、表C数据导入，上传上来。

或者，直接把你的项目上传上来。

改一下

Select Case e.DataCol.name
    Case "配料日期"
        If e.NewValue Is Nothing Then
            e.DataRow("结算日期") = Nothing
        Else
            Dim dt As Date = e.NewValue
            If dt.Day > 25 Then '如果为25日以后的日期
                dt = new Date(dt.year,dt.month,1) '改为下个月的第一天
                dt= dt.AddMonths(1)
            End If
            e.DataRow("结算日期") = dt
        End If
End Select

Select Case e.DataCol.name
    Case "报料阶段", "使用工艺名称"
        If e.DataRow.isnull("报料阶段")= False AndAlso e.DataRow.isnull("使用工艺名称") = False Then
            Dim Cols1() As String = {"使用工序","加料序号","材料名称","用量百分比","材料干湿"}
            Dim Cols2() As String = {"使用工序","加料序号","材料名称","用量百分比","材料干湿"}
            Dim drs As List(Of DataRow) = DataTables("工艺配方").Select("报料阶段 = '" & e.DataRow("报料阶段") & "' and 使用工艺名称 = '" & e.DataRow("使用工艺名称") & "'")
            systemready = False
            For i As Integer = 0 To drs.count-1
                Dim dr2 As DataRow
                If i = 0 Then
                    dr2 = e.DataRow
                Else
                    dr2 = e.DataTable.addnew
                End If
                For j As Integer = 0 To Cols1.Length -1
                    dr2(Cols2(j)) = drs(i)(Cols1(j))
                Next
               
                dr2("报料阶段") = e.DataRow("报料阶段")
                dr2("使用工艺名称") = e.DataRow("使用工艺名称")
               
            Next
            systemready = True
        End If
End Select