主题：[求助]列内容变化后计算

For Each n As String In DataTables("产品").GetValues("GPS产品名称", "GPS产品名称 is not null")

    Dim dr1 As DataRow = DataTables("产品").Find("GPS产品名称 = '" & n & "'", "日期")

    Dim dr2 As DataRow = DataTables("产品").Find("GPS产品名称 = '" & n & "'", "日期 desc")

    Dim fdr As DataRow = DataTables("表C").Find("第一列 = '" & n & "'")

    If fdr Is Nothing Then

        fdr = DataTables("表C").AddNew

        fdr("第一列") = n

    End If

    Dim x1 As Double = dr1("经度")

    Dim y1 As Double = dr1("纬度")

    Dim x2 As Double = dr2("经度")

    Dim y2 As Double = dr2("纬度")

    

    Dim rad As Double = 6371

    Dim p1X As Double = X1 / 180 * Math.PI

    Dim p1Y As Double = Y2 / 180 * Math.PI

    Dim p2X As Double = X2 / 180 * Math.PI

    Dim p2Y As Double = Y2 / 180 * Math.PI

    Dim result As Double = Math.Acos(Math.Sin(p1Y) * Math.Sin(p2Y) + Math.Cos(p1Y) * Math.Cos(p2Y) * Math.Cos(p2X - p1X)) * rad

    fdr("第三列") = result

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