如何将VB.net与Excel工作表一起使用以对数据进行计数和排序

Question

Just like the title says, I've been using VB.NET to do various things on Excel and am kinda new. If i have an Excel sheet with various data including staff and things sold, how can i select 2 Columns and sort them so it counts how many of each items were sold by each person into a Messagebox or Listbox?

for eg, the output i'm looking for is something like

Staff   Sold       how many
NAME1 - PRODUCT1 - AMOUNTSOLDBYNAME1
NAME1 - PRODUCT2 - AMOUNTSOLDBYNAME1
NAME1 - PRODUCT3 - AMOUNTSOLDBYNAME1
NAME1 - PRODUCT4 - AMOUNTSOLDBYNAME1
NAME2 - PRODUCT1 - AMOUNTSOLDBYNAME2
NAME2 - PRODUCT2 - AMOUNTSOLDBYNAME2

and so on...

the furthest i've gotten is counting how many of each staff member there are in 1 column but i would like to go a step further on this and get 2 columns and count each product sold by each person but am unclear how to go about it.

Private Sub getexcelfile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
    Dim excelfile As New OpenFileDialog()
    excelfile.ShowDialog()
    If (excelfile.ShowDialog() = DialogResult.Cancel) Then
        Return
    Else
        Dim file As String = excelfile.FileName
        Dim xlApp As Excel.Application
        Dim xlWorkBook As Excel.Workbook
        Dim xlWorkSheet As Excel.Worksheet

        xlApp = New Excel.Application
        xlWorkBook = xlApp.Workbooks.Open(file)
        xlWorkSheet = xlWorkBook.Worksheets("PSSalesFullConnectionReport")

        Dim col As String = "N"
        For row As Integer = 1 To xlWorkSheet.UsedRange.Rows.Count - 1
            Dim elemValue As String = xlWorkSheet.Range(col & row).Text
            ListBox1.Items.Add(elemValue)
        Next

        MessageBox.Show(ReturnDuplicateListBoxItems(ListBox1))

        ListBox1.Items.Clear()

    End If

End Sub

Public Shared Function ReturnDuplicateListBoxItems(ByVal lBox As System.Windows.Forms.ListBox) As String
    Dim strReturn As New System.Text.StringBuilder
    Dim lItems As New Dictionary(Of String, Integer)
    Dim intCount As Integer = 0
    Dim strCurrentItem As String = String.Empty

    Try
        For Each nItem As String In lBox.Items
            If Not (lItems.ContainsKey(nItem)) Then
                strCurrentItem = nItem
                For Each sItem As String In lBox.Items
                    If sItem.Equals(strCurrentItem) Then
                        intCount += 1
                    End If
                Next
                lItems.Add(nItem, intCount)
                intCount = 0
                strCurrentItem = String.Empty
            End If
        Next

        For i As Integer = 0 To lItems.Count - 1
            strReturn.AppendLine(lItems.Keys(i).ToString & " - " & lItems.Values(i).ToString)
        Next

    Catch ex As Exception
        Return strReturn.ToString
    End Try

    Return strReturn.ToString
End Function

any guidance on this would help me alot

Answer 1

Slight delay on the answer, but here is relevant code for creating a Pivot Table from Interop (sorry, it's C#) and then using that Pivot Table to summarize the results. This is nice because once the Pivot Table is done, you know that you have all the unique entries sorted. You can then iterate the Pivot Table to get the results that you want. For some cases, this may be easier than building out all the logic on the .NET side of things since Excel is so good at aggregating data. The downside is you have to create the Pivot Table.

This is full code to create dummy data and summarize it to be as general as possible.

//up above is a namespace usage that defines:
//using Excel = Microsoft.Office.Interop.Excel;
private void button1_Click(object sender, EventArgs e)
{
    Excel.Application xl_app = new Excel.Application();

    Excel.Workbook wkbk = xl_app.Workbooks.Add();
    Excel.Worksheet sht = wkbk.Worksheets[1];

    xl_app.Visible = true;

    //create some dummy data... not using an array.. I know
    Random rnd = new Random();

    int rows = 100;
    for (int i = 0; i < rows; i++)
    {
        sht.Cells[2 + i, 1].Value = "NAME" + rnd.Next(5);
        sht.Cells[2 + i, 2].Value = "PROD" + rnd.Next(5);
        sht.Cells[2 + i, 3].Value =  rnd.Next(10);
    }

    sht.Cells[1, 1].Value = "STAFF";
    sht.Cells[1, 2].Value = "SOLD";
    sht.Cells[1, 3].Value = "HOW MANY";

    //create the pivot table
    Excel.PivotCache pc = wkbk.PivotCaches().Add(
        Excel.XlPivotTableSourceType.xlDatabase, 
        sht.get_Range("A1").CurrentRegion);

    Excel.PivotTable pt = sht.PivotTables().Add(pc, sht.get_Range("F1"));

    pt.PivotFields("STAFF").Orientation = Excel.XlPivotFieldOrientation.xlRowField;
    pt.PivotFields("SOLD").Orientation = Excel.XlPivotFieldOrientation.xlRowField;

    pt.AddDataField(pt.PivotFields("HOW MANY"), Type.Missing, Excel.XlConsolidationFunction.xlSum);
    //formatting here ensures it is a table with no extra values

    foreach (Excel.PivotField pf in pt.PivotFields())
    {
        pf.Subtotals[1] = false;
    }

    pt.ColumnGrand = false;
    pt.RowGrand = false;

    pt.RowAxisLayout(Excel.XlLayoutRowType.xlTabularRow);
    pt.RepeatAllLabels(Excel.XlPivotFieldRepeatLabels.xlRepeatLabels);

    //now we need to go through the Pivot Table to get data

    Excel.Range rng_start = sht.get_Range("F3");

    foreach (Excel.Range rng_cell in 
        sht.get_Range(
            rng_start, 
            rng_start.get_End(Excel.XlDirection.xlDown)))
    {
        Console.WriteLine("{0} - {1} - {2}",
            rng_cell.Value,
            rng_cell.get_Offset(0, 1).Value,
            rng_cell.get_Offset(0, 2).Value);
    }

}

Picture of the resulting Workbook has the Pivot Table over the on the side:

Console output includes rows that have the results. Shown are the last couple lines:

...
NAME4 - PROD0 - 7
NAME4 - PROD1 - 11
NAME4 - PROD2 - 10
NAME4 - PROD3 - 17
NAME4 - PROD4 - 23