Programmatically enable Excel macro in C#

Question

I have an Excel add-in, and I would like to do the following:

1. Check if the workbook has macro.
2. Prompt user if he wants to enable the macro.
3. If yes, enable the macro for user.

Is there a way to enable a macro in C#?

Answer 1

This article is very helpful for you.

According to the article, I implemented this as a WinForm application so I used MessageBox to prompt user if he wants to enable the macro.

Before doing this, you have to check "Trust access to the VBA project object model" at [File]->[Options]->[Trust Center] in your "xlsm" workbook.

using VBA = Microsoft.Vbe.Interop;
using Excel = Microsoft.Office.Interop.Excel;

private void ReadExcel()
{
    string filePath = @"C:\temp\Macro.xlsm";

    Microsoft.Office.Interop.Excel.Application appExcel = null;
    Microsoft.Office.Interop.Excel.Workbooks workbooks = null;
    Microsoft.Office.Interop.Excel.Workbook workbook = null;

    object oMiss = System.Reflection.Missing.Value;

    appExcel = new Microsoft.Office.Interop.Excel.Application();
    appExcel.DisplayAlerts = true;
    appExcel.AutomationSecurity = Microsoft.Office.Core.MsoAutomationSecurity.msoAutomationSecurityByUI;
    // Make the excel visible
    appExcel.Visible = true;
    workbooks = appExcel.Workbooks;
    workbook = workbooks.Open(filePath, oMiss,
                              oMiss, oMiss,
                              oMiss, oMiss,
                              oMiss, oMiss,
                              oMiss, oMiss,
                              oMiss, oMiss,
                              oMiss, oMiss,
                              oMiss);

    if (workbook.HasVBProject)  // Has macros
    {
        try
        {
            // Show "Microsoft Excel Security Notice" prompt
            var project = workbook.VBProject;
        }
        catch (System.Runtime.InteropServices.COMException comex)
        {
            // Macro is enabled.
        }
    }

    workbook.Close(true, oMiss, oMiss);

    System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
    workbook = null;
    System.Runtime.InteropServices.Marshal.ReleaseComObject(workbooks);
    workbooks = null;
    appExcel.Quit();
    System.Runtime.InteropServices.Marshal.ReleaseComObject(appExcel);
    appExcel = null;
}