创建pdf文件后，c＃excel不会清理
我已经成功地使用下面的代码将Excel文件转换为PDF文件。
我试图用下面的方法释放excel对象。
- 退出并关闭＆null
- 切勿对COM对象使用双点
- ReleaseComObject
- GC.Collect
但是，在任务管理器中仍然保留“EXCEL.EXE”。
我不想通过调用任务管理器中的进程列表来终止“EXCEL.EXE”
我该如何解决这个问题？
public bool ExportWorkbookToPdf(string workbookPath, string outputPath)
{
// If either required string is null or empty, stop and bail out
if (string.IsNullOrEmpty(workbookPath) || string.IsNullOrEmpty(outputPath))
{
return false;
}
// Create COM Objects
Microsoft.Office.Interop.Excel.Application excelApplication;
Microsoft.Office.Interop.Excel.Workbooks excelWorkbooks;
Microsoft.Office.Interop.Excel.Workbook excelWorkbook;
// Create new instance of Excel
//var excelApplication = new Microsoft.Office.Interop.Excel.Application();
excelApplication = new Microsoft.Office.Interop.Excel.Application();
// Make the process invisible to the user
excelApplication.ScreenUpdating = false;
// Make the process silent
excelApplication.DisplayAlerts = false;
// Open the workbook that you wish to export to PDF
excelWorkbooks = excelApplication.Workbooks;
excelWorkbook = excelWorkbooks.Open(workbookPath);
// If the workbook failed to open, stop, clean up, and bail out
if (excelWorkbook == null)
{
//excelApplication.Application.Quit();
excelApplication.Quit();
excelWorkbook = null;
excelWorkbooks = null;
excelApplication = null;
return false;
}
var exportSuccessful = true;
try
{
excelWorkbook.ExportAsFixedFormat(Microsoft.Office.Interop.Excel.XlFixedFormatType.xlTypePDF, outputPath);
}
catch (System.Exception ex)
{
// Mark the export as failed for the return value...
exportSuccessful = false;
// Do something with any exceptions here, if you wish...
// MessageBox.Show...
}
finally
{
// Close the workbook, quit the Excel, and clean up regardless of the results...
excelWorkbook.Close();
excelWorkbooks.Close();
excelApplication.Quit();
excelWorkbook = null;
excelWorkbooks = null;
excelApplication = null;
ReleaseExcelObject(excelWorkbook);
ReleaseExcelObject(excelWorkbooks);
ReleaseExcelObject(excelApplication);
}
return exportSuccessful;
}
private static void ReleaseExcelObject(object obj)
{
try
{
if (obj != null)
{
Marshal.ReleaseComObject(obj);
obj = null;
}
}
catch (Exception ex)
{
obj = null;
throw ex;
}
finally
{
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
GC.WaitForPendingFinalizers();
}
}
在你最后的声明中，你将excelWorkbook，excelWorkbooks＆excelApplication设置为null，然后使用相同的引用传递给ReleaseExcelObject - 所以你有效地调用了ReleaseExcelObject（null）; 除了调用GCCollect之外什么都不做。 尝试交换订单。
此外，在代码的早期 - 如果您无法打开工作簿，则只需退出应用程序并将参考设置为空。 您可以尝试将工作簿打开到try语句中，以便在finally语句中清除错误条件，而不需要重复代码。
沿着以下方向的东西：
var exportSuccessful = true;
try
{
excelWorkbook = excelWorkbooks.Open(workbookPath);
// If the workbook failed to open, stop, clean up, and bail out
if (excelWorkbook == null)
return false;
excelWorkbook.ExportAsFixedFormat(Microsoft.Office.Interop.Excel.XlFixedFormatType.xlTypePDF, outputPath);
}
catch (System.Exception ex)
{
// Mark the export as failed for the return value...
exportSuccessful = false;
// Do something with any exceptions here, if you wish...
// MessageBox.Show...
}
finally
{
// Close the workbook, quit the Excel, and clean up regardless of the results...
excelWorkbook?.Close();
excelWorkbooks?.Close();
excelApplication?.Quit();
ReleaseExcelObject(excelWorkbook);
ReleaseExcelObject(excelWorkbooks);
ReleaseExcelObject(excelApplication);
excelWorkbook = null;
excelWorkbooks = null;
excelApplication = null;
}