文件正在由另一个进程C＃visual studio使用

Question

I have created a (Web application) web scheduler to call a method every 5min in global.asax file. It is getting triggered successfully.

In the method I am creating excel using interop dll and doing 'save as' as operation. First I am checking if file exists in the folder, if exists I am deleting it and doing "save as" operation. For the first time it works fine. For second call when the file exists I am not able to delete it. It says file is being used by another process.

Once the debugger is stopped and run again I am able to delete the file, that too it only works for the first time.

I think visual studio (Asp.net development server) is locking the file. once the development server is stopped I am able to delete it.

Please find the code below:-

 string fullFileName = Path.Combine(Path.GetTempPath(), testf); FileInfo TheFileInfo = new FileInfo(filePath); if (TheFileInfo.Exists) { File.Delete(fullFileName); } xlWorkBook.SaveAs(fullFileName, Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue,misValue); //xlApp = new Microsoft.Office.Interop.Excel.ApplicationClass(); GC.Collect(); GC.WaitForPendingFinalizers(); xlWorkBook.Close(true, misValue, misValue); xlApp.Quit(); xlApp.Application.Quit(); System.Runtime.InteropServices.Marshal.FinalReleaseComObject(chartRange); System.Runtime.InteropServices.Marshal.FinalReleaseComObject(xlWorkSheet); System.Runtime.InteropServices.Marshal.FinalReleaseComObject(xlWorkBook); System.Runtime.InteropServices.Marshal.FinalReleaseComObject(xlApp); 

Please help to fix this issue.

Answer 1

You must have created object to access excel file. Try closing that object strictly. If that object is not disposed then you'll get this error. Excel objects are heavy.

Answer 2

Microsoft does not currently recommend, and does not support, Automation of Microsoft Office applications from any unattended, non-interactive client application or component (including ASP, ASP.NET, DCOM, and NT Services), because Office may exhibit unstable behavior and/or deadlock when Office is run in this environment.

If you are building a solution that runs in a server-side context, you should try to use components that have been made safe for unattended execution. Or, you should try to find alternatives that allow at least part of the code to run client-side. If you use an Office application from a server-side solution, the application will lack many of the necessary capabilities to run successfully. Additionally, you will be taking risks with the stability of your overall solution. Read more about that in the Considerations for server-side Automation of Office article.

You may consider using the Open XML SDK, see Welcome to the Open XML SDK 2.5 for Office for more information. Or any other third-party components designed for the server-side execution.