Excel VSTO自动筛选器无法正常工作吗？

Question

I'm working on a Excel VSTO project with Office & VS 2010. I have the code to get a range but I can't seem to get the Autofilter to work right. Heres the code I have so far:

Excel.Workbook wb = (Excel.Workbook)Globals.ThisWorkbook.InnerObject;
Excel.Name rngN = wb.Names.Item("MyNamedRange", System.Type.Missing, System.Type.Missing);
Excel.Range rng = rngN.RefersToRange;
int allRows = rng.Rows.Count;
rng.AutoFilter(8, "ST", Microsoft.Office.Interop.Excel.XlAutoFilterOperator.xlOr, System.Type.Missing, null);
int filteredRows = rng.Rows.Count;

However, in this example, the row counts are identical and my range is not filtered at all - Im referring to the variables allRows and filteredRows above. So I'm either not implementing the filter correctly and or my filter statement is wrong. My filter line:

rng.AutoFilter(8, "ST", Microsoft.Office.Interop.Excel.XlAutoFilterOperator.xlOr, System.Type.Missing, null);

So my understanding is that this line would look for all matches of "ST" in the 8th field. Is that not correct? Why are my record counts the same?

Answer 1

In answer to the second part of your question, getting the number of filtered rows is tricky. rng.Rows.Count will return the original number of rows, not the filtered number.

You can use an expression like the following:

Evaluate("=SUBTOTAL(3," & Range("A:A").Address & ")-1")

which you can store in an integer - you may have to cast the result.

3 represents the COUNTA function (excluding the filtered rows) and I'm subtracting 1 to exclude the header row. Increase this number if there are other occupied cells in the column.

You could store this formula temporarily in a cell, but I believe it should return a result using Evaluate() .

Added Read

rng.SpecialCells(xlCellTypeVisible).Count

before and after applying the filter to determine whether the filter worked.

There is useful information about Excel filtering at this MSDN link .