使用C＃Excel Interop在Excel中计算用户定义的函数

Question

I am trying to an Add-in directly from C# so that when I open a workbook, and do a Workbook.Calculate() the UDF's (User Defined Functions) that are defined in an external addin correctly calculate in the worksheet. Currently, I am looping through each adding and simple setting:

AddIn.Installed = true

This does not work. C# does not load add-in at all, and I want to avoid using VBA. I want to open a workbook an excel workbook with the specific add in loaded, do a full calculated, and should have all values of the worksheet updated, including cells with UDF's.

Thanks for any help....

Some code:

Excel.Workbook wkbk = ExcelApp.ActiveWorkbook;

        Excel.XlFixedFormatType paramExportFormat = Excel.XlFixedFormatType.xlTypePDF;
        Excel.XlFixedFormatQuality paramExportQuality = Excel.XlFixedFormatQuality.xlQualityStandard;
        bool paramOpenAfterPublish = false;
        bool paramIncludeDocProps = true;
        bool paramIgnorePrintAreas = true;
        object paramFromPage = Type.Missing;
        object paramToPage = Type.Missing;

        ExcelApp.Visible = true;
        //foreach (Excel.AddIn aiTemp in ExcelApp.AddIns)
        //{
        //    if (aiTemp.Name.Contains(""))
        //    {
        //        aiTemp.Installed = false;
        //        aiTemp.Installed = true;
        //    }
        //}            

        while (ExcelApp.CalculationState == Microsoft.Office.Interop.Excel.XlCalculationState.xlCalculating)
        {
            Thread.Sleep(50);
        }
        ExcelApp.CalculateFull();
        var wksht = wkbk.ActiveSheet;
        Excel.Range rng = ((Excel.Worksheet)wksht).get_Range("B1", "B1");
        rng.Calculate();
        //EnsureCalcFinished();

        ExcelApp.Visible = false;
        wkbk.ExportAsFixedFormat(Microsoft.Office.Interop.Excel.XlFixedFormatType.xlTypePDF, PathToDocument.Replace(".xlsx", ".pdf"), paramExportQuality, true, false, Type.Missing, Type.Missing, true,Type.Missing);

Answer 1

UPDATE: I found a link with the method I use to register UDFs.

Ref: http://msdn.microsoft.com/en-us/library/ms173189(v=vs.80).aspx

In Excel, you need to go to Options -> Add-Ins => Excel Add-in (Go..) => automation = select the library and hit OK. Once you do this once, it'll be auto-loaded each time you open excel.

Answer 2

Here is the algorithm to load excel AddIns so that when you open excel workbook, a calculation will include UDF's defined in Add-in:

1)Initiliaze Excel Application

ExcelApp = new Excel.Application();

2)Load AddIns *

 foreach (Excel.AddIn ai in ExcelApp.AddIns)
        {
            ai.Installed = false;
            ai.Installed = true;
            ExcelApp.Wait(50);
        }

**The Key is to load add-ins before you open Excel Workbook.

3)Open Excel Workbook, which will trigger calculations

4)Set Calculation Mode to manual so that any changes in Interop do not trigger lengthy recalc

ExcelApp.Calculation = Microsoft.Office.Interop.Excel.XlCalculation.xlCalculationManual;  

5)Perform any manipulations, and perform calc

ExcelApp.CalculateFull();

6)Dispose of Excel Objects appropriately

Hope this helps someone with a similar issue.. Ended up being a simple fix for a simple problem. Just remember to load add-ins before opening the workbook. Otherwise, opening an excel workbook with UDF's dependent on AddIn will fail.