如何关闭Excel com对象并保存工作？

这让我快发疯了。我在这里找到了关于Excel com对象的类似帖子，但我尝试的解决方案中没有一个能够在代码运行完成后成功关闭Excel。Excel.dll将保留在TaskManager上

有人可以看看我下面的代码，让我知道为什么Excel无法关闭吗

Try
        'First get an application instance
        xlApp = New Excel.Application()
        'Second open the workbook you need
        xlBook = xlApp.Workbooks.Open(_FileInfo.FullName)
        xlSheet = xlBook.Worksheets(sheetName)
        'set visibility
        xlApp.Visible = False
        Dim row As Integer = 2
        For Each t In upsRecordList
            While (row < upsRecordList.Count + 2)
                xlSheet.Cells(row, 1) = t.StartDate
                xlSheet.Cells(row, 2) = t.AccountTypeCode
                row += 1
            End While
        Next
    Catch ex As Exception
        Throw ex
    Finally
        If Not xlApp Is Nothing Then
            GC.Collect()
            GC.WaitForPendingFinalizers()
            GC.Collect()
            GC.WaitForPendingFinalizers()
            NAR(xlSheet)
            If Not xlBook Is Nothing Then
                xlBook.Close(SaveChanges:=True)
                NAR(xlBook)
            End If
            xlApp.Quit()
            NAR(xlApp)
        End If
    End Try

 Private Sub NAR(ByVal o As Object)
    Try
        Marshal.FinalReleaseComObject(o)
    Catch
    Finally
        o = Nothing
    End Try
End Sub

---

你的代码很好。释放对象时，Excel不会总是完全关闭，甚至使用Quit方法也不会完全关闭

我想您可以迭代运行任务，强制终止它，但我不建议这样做。

以下是我所做的：

将Excel实例保持为单例：

// Our singleton excel instance
private static Excel.Application instance;

/// <summary>
/// Returns an instance of an Excel Application.
/// This instance is a singleton.
/// </summary>
public static Excel.Application GetInstance
{
    get
    {
        if (instance == null)
        {
            try
            {
                instance = new Excel.Application();
                // Give the app a GUID so we can kill it later
                instance.Caption = System.Guid.NewGuid().ToString().ToUpper(CultureInfo.CurrentCulture);
                instance.Visible = false;
            }
            catch (COMException ce)
            {
                ShowMessage(ce.Message, MessageBoxIcon.Error);
            }
        }
        return instance;
    }
}

此方法看起来像：

/// <summary>
/// This method contains a number of ways to try and kill
/// the Excel process created when an instance is instantiated.
/// </summary>
/// <param name="windowHandle">Handle of the application window</param>
/// <param name="caption">A custom GUI stored as the app's caption</param>
public static void EnsureProcessKilled(IntPtr windowHandle, String caption)
{
    NativeMethods.SetLastError(0);
    if (IntPtr.Equals(windowHandle, IntPtr.Zero))
    {
        windowHandle = NativeMethods.FindWindow(null, caption);
    }
    if (IntPtr.Equals(windowHandle, IntPtr.Zero))
    {
        // Can't find the window; assumed it's closed
        return;
    }
    int resourceId;
    int processId = 0;
    resourceId = NativeMethods.GetWindowThreadProcessId(windowHandle, ref processId);
    if (processId == 0)
    {
        // Can't get process id
        if (NativeMethods.EndTask(windowHandle) != 0)
        {
            return; // Success
        }
    }
    // Couldn't end it nicely, let's kill it
    System.Diagnostics.Process process;
    process = System.Diagnostics.Process.GetProcessById(processId);
    process.CloseMainWindow();
    process.Refresh();
    if (process.HasExited)
    {
        return;
    }
    // If we get here, it's being really stubborn.  Say goodbye, EXCEL.EXE!
    process.Kill();
}

还有一个小助手函数：

public static void Release(Object releasable)
{
    System.Runtime.InteropServices.Marshal.ReleaseComObject(releasable);
    releasable = null;
}

---

这是我的最后一个街区；AFAIK这并没有在我们的应用程序中发布Excel失败。我们让Excel保持打开状态，并依靠用户关闭它。需要针对您引用的Excel对象自定义对Marshal.finalEleaseComObject的调用

        finally
        {
            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();
            GC.WaitForPendingFinalizers();
            // Calls are needed to avoid memory leak
            Marshal.FinalReleaseComObject(sheet);
            Marshal.FinalReleaseComObject(book);
            Marshal.FinalReleaseComObject(excel);
        }

---

从Quit语句中删除参数：xlApp.Quit

---

在该行之后立即添加以下内容：Set xlApp=Nothing

Me now registered。另一件事-不要对Excel参数使用parens，除非将值传递到变量中。代码应如下所示：

   If Not xlApp Is Nothing Then
        GC.Collect()
        GC.WaitForPendingFinalizers()
        GC.Collect()
        GC.WaitForPendingFinalizers()
        NAR(xlSheet)
        If Not xlBook Is Nothing Then
            xlBook.Close True
            xlBook = Nothing
        End If
        xlApp.Quit
        xlApp = Nothing
    End If

---

这是一个大问题。如果用户在Excel中打开了另一个电子表格，该怎么办？你也会终止的！这个想法是完全终止作为COM对象创建的Excel实例。这个答案满足了提出的问题。+1是的，Cory是对的，这个问题显示了创建Excel新实例的自动化，并且正确地将可见性设置为“false”。在这种情况下，用户无法打开另一个电子表格，也不应允许用户打开。Cory，我不确定，在这里使用“FindWindow”API会有任何好处，我想你可以放弃它。当然不能指望标题是唯一的，下一个使用“GetWindowThreadProcessId”的部分应该总是有效的。只是一个想法。。。

        finally
        {
            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();
            GC.WaitForPendingFinalizers();
            // Calls are needed to avoid memory leak
            Marshal.FinalReleaseComObject(sheet);
            Marshal.FinalReleaseComObject(book);
            Marshal.FinalReleaseComObject(excel);
        }

   If Not xlApp Is Nothing Then
        GC.Collect()
        GC.WaitForPendingFinalizers()
        GC.Collect()
        GC.WaitForPendingFinalizers()
        NAR(xlSheet)
        If Not xlBook Is Nothing Then
            xlBook.Close True
            xlBook = Nothing
        End If
        xlApp.Quit
        xlApp = Nothing
    End If