主题：判断重复值

Dim dic As new Dictionary(of String,String)

For Each dr As DataRow In DataTables("表A").datarows

    If dic.ContainsKey(dr("日期"))=False AndAlso dic.ContainsValue (dr("姓名"))=False Then

        Dim drList As List(of DataRow)=DataTables("表A").Select("日期='" & dr("日期") & "' and 姓名='" & dr("姓名") & "'" )

        If drList IsNot Nothing Then

            For i As Integer=0 To drList.count-1

                If i= 0 Then

                    drList(i)("考勤")=1

                Else

                    drList(i)("考勤")=0

                End If

            Next

        End If

        dic.Add(dr("日期"),dr("姓名"))

    End If

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