如何使用 IronXL 在 C# 中關閉 Excel 進程

using Excel = Microsoft.Office.Interop.Excel;
class Program
{
    static void Main(string[] args)
    {
        Excel.Application excelApp = null;
        Excel.Workbook book = null;
        Excel.Worksheet sheet = null;
        try
        {
            excelApp = new Excel.Application();
            book = excelApp.Workbooks.Open(@"C:\data\report.xlsx");
            sheet = (Worksheet?)book.Worksheets[1];
            // Perform operations
            string data = (sheet.Cells[1, 1] as Range)?.Value2?.ToString();
            book.Save();
            book.Close(false);
            excelApp.Quit();
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error: {ex.Message}");
        }
        finally
        {
            // The "correct way" according to traditional guidance, c# close excel process
            if (sheet != null) Marshal.ReleaseComObject(sheet);
            if (book != null) Marshal.ReleaseComObject(book);
            if (excelApp != null) Marshal.ReleaseComObject(excelApp);
            sheet = null;
            book = null;
            excelApp = null;
            GC.Collect();
            GC.WaitForPendingFinalizers();
        }
    }
}

Imports Excel = Microsoft.Office.Interop.Excel
Imports System.Runtime.InteropServices

Class Program
    Shared Sub Main(ByVal args As String())
        Dim excelApp As Excel.Application = Nothing
        Dim book As Excel.Workbook = Nothing
        Dim sheet As Excel.Worksheet = Nothing
        Try
            excelApp = New Excel.Application()
            book = excelApp.Workbooks.Open("C:\data\report.xlsx")
            sheet = CType(book.Worksheets(1), Excel.Worksheet)
            ' Perform operations
            Dim data As String = CType(sheet.Cells(1, 1), Excel.Range)?.Value2?.ToString()
            book.Save()
            book.Close(False)
            excelApp.Quit()
        Catch ex As Exception
            Console.WriteLine($"Error: {ex.Message}")
        Finally
            ' The "correct way" according to traditional guidance, VB.NET close excel process
            If sheet IsNot Nothing Then Marshal.ReleaseComObject(sheet)
            If book IsNot Nothing Then Marshal.ReleaseComObject(book)
            If excelApp IsNot Nothing Then Marshal.ReleaseComObject(excelApp)
            sheet = Nothing
            book = Nothing
            excelApp = Nothing
            GC.Collect()
            GC.WaitForPendingFinalizers()
        End Try
    End Sub
End Class

using System.Diagnostics;
class Program
{
    static void Main(string[] args)
    {
        // Store process IDs before opening Excel
        var existingProcessIds = Process.GetProcessesByName("EXCEL")
            .Select(p => p.Id)
            .ToHashSet();
        Excel.Application excelApp = new Excel.Application();
        try
        {
            // Perform Excel operations
            // ...
        }
        finally
        {
            excelApp.Quit();
            // Find and kill all new Excel processes
            foreach (Process proc in Process.GetProcessesByName("EXCEL"))
            {
                if (!existingProcessIds.Contains(proc.Id))
                {
                    try
                    {
                        proc.Kill();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine($"Unable to kill process: {ex.Message}");
                    }
                }
            }
        }
    }
}

Imports System.Diagnostics
Imports System.Linq
Imports Excel = Microsoft.Office.Interop.Excel

Module Program
    Sub Main(args As String())
        ' Store process IDs before opening Excel
        Dim existingProcessIds = Process.GetProcessesByName("EXCEL") _
            .Select(Function(p) p.Id) _
            .ToHashSet()
        Dim excelApp As New Excel.Application()
        Try
            ' Perform Excel operations
            ' ...
        Finally
            excelApp.Quit()
            ' Find and kill all new Excel processes
            For Each proc As Process In Process.GetProcessesByName("EXCEL")
                If Not existingProcessIds.Contains(proc.Id) Then
                    Try
                        proc.Kill()
                    Catch ex As Exception
                        Console.WriteLine($"Unable to kill process: {ex.Message}")
                    End Try
                End If
            Next
        End Try
    End Sub
End Module

// Save with password encryption
workBook.SaveAs("confidential_data.xlsx", "SecurePassword123");

// Traditional approach with event handler - problematic
public void ProcessExcel()
{
    Excel.Application excelApp = new Excel.Application();
    excelApp.WorkbookBeforeClose += OnWorkbookClose;
    // Even with cleanup, the event handler reference persists
    // The Excel app stays open because of this reference
}
private void OnWorkbookClose(Excel.Workbook Wb, ref bool Cancel)
{
    // Handler code
}

Imports Excel

Public Sub ProcessExcel()
    Dim excelApp As New Application()
    AddHandler excelApp.WorkbookBeforeClose, AddressOf OnWorkbookClose
    ' Even with cleanup, the event handler reference persists
    ' The Excel app stays open because of this reference
End Sub

Private Sub OnWorkbookClose(ByVal Wb As Workbook, ByRef Cancel As Boolean)
    ' Handler code
End Sub