该进程无法访问文件'xxx'，因为当使用ReportViewer进行PDF扩展时，其他进程正在使用该文件

Question

尝试使用reportviewer导出导出PDF时，我收到此错误/摘要 该进程无法访问该文件＆＃39; xxx＆＃39;因为它正被另一个进程使用

public bool Export(string accountNumber, DateTime settlementDateTime, string PDFfileName, out string errorMsg)
    {
        bool success;
        ReportViewer reportViewer;
        Warning[] warnings;
        ReportParameter[] rptParameters;
        string[] streamids;
        string mimeType;
        string encoding;
        string filenameExtension;
        byte[] bytes;

        success = false;
        errorMsg = string.Empty;

        try
        {
            Console.Out.WriteLine(String.Format("Generando extracto para la cuenta \"{0}\" de la fecha {1}", accountNumber, settlementDateTime));
            reportViewer = new ReportViewer();

            // Set Processing Mode
            reportViewer.ProcessingMode = ProcessingMode.Remote;

            //set the URL of the report to execute
            reportViewer.ServerReport.ReportServerUrl = new Uri(repServerURL);
            reportViewer.ServerReport.ReportPath = repPath ;

            //Create the parameters that the report needs
            rptParameters = new ReportParameter[2];

            rptParameters[0] = new ReportParameter();
            rptParameters[0].Name = "rptPrm_AccountNumber";
            rptParameters[0].Values.Add(accountNumber);

            rptParameters[1] = new ReportParameter();
            rptParameters[1].Name = "rptPrm_Date";
            string dateAsString;

            dateAsString = settlementDateTime.ToString();
            rptParameters[1].Values.Add(dateAsString);

            reportViewer.ServerReport.SetParameters(rptParameters);

            // Process and render the report
            reportViewer.ServerReport.Refresh();

            //Render it to PDF and take the bytes to the FileStream
            bytes = reportViewer.ServerReport.Render(
                "PDF", null, out mimeType, out encoding, out filenameExtension,
                out streamids, out warnings);

            using (FileStream fs = new FileStream(Path.Combine(exportPath, PDFfileName), FileMode.Create))
            {
                fs.Write(bytes, 0, bytes.Length);
                fs.Close();
            }
            reportViewer.Dispose(); 

            success = true;
        }
        catch (Exception ex)
        {
            errorMsg = ex.Message;
            Console.Error.WriteLine(String.Format("Se presento error al generar extracto para la cuenta \"{0}\" de la fecha {1}-{2}", accountNumber, settlementDateTime, errorMsg));
        }

        return success;
    }
}

重要的是要提到在调用导出方法之前我通过调用此方法删除文件夹中的所有PDF文件

 private bool DeletePDFfiles(StringBuilder sbLog)
    {
        bool exito;
        List<string> lstFiles;

        exito = true;
        lstFiles = new List<string>(Directory.GetFileSystemEntries(this.settings.folderWithFilesToSend, "*.pdf"));

        if ((lstFiles != null) && (lstFiles.Count > 0))
        {
            foreach (string existingPDFfile in lstFiles)
            {

                try
                {
                    File.Delete(existingPDFfile);
                }

                catch (Exception ex)
                {
                    //Si el archivo no pudo ser borrado 
                    sbLog.Append(string.Format("Error {0} al borrar el archivo {0}", ex.Message, existingPDFfile));
                    exito = false;
                }

            }
        }

        return exito;
    }

Answer 1

通过设置reportviewer = null并将finally添加到catch

来解决

public bool Export(string accountNumber, DateTime settlementDateTime, string PDFfileName, out string errorMsg)
    {
        bool success;
        ReportViewer reportViewer;
        Warning[] warnings;
        ReportParameter[] rptParameters;
        string[] streamids;
        string mimeType;
        string encoding;
        string filenameExtension;
        byte[] bytes;
        FileStream fs ;

        success = false;
        errorMsg = string.Empty;
        fs = null ;    
        reportViewer = null ;

        try
        {
            Console.Out.WriteLine(String.Format("Generando extracto para la cuenta \"{0}\" de la fecha {1}", accountNumber, settlementDateTime));
            reportViewer = new ReportViewer();

            // Set Processing Mode
            reportViewer.ProcessingMode = ProcessingMode.Remote;

            //set the URL of the report to execute
            reportViewer.ServerReport.ReportServerUrl = new Uri(repServerURL);
            reportViewer.ServerReport.ReportPath = repPath ;

            //Create the parameters that the report needs
            rptParameters = new ReportParameter[2];

            rptParameters[0] = new ReportParameter();
            rptParameters[0].Name = "rptPrm_AccountNumber";
            rptParameters[0].Values.Add(accountNumber);

            rptParameters[1] = new ReportParameter();
            rptParameters[1].Name = "rptPrm_Date";
            string dateAsString;

            dateAsString = settlementDateTime.ToString();
            rptParameters[1].Values.Add(dateAsString);

            reportViewer.ServerReport.SetParameters(rptParameters);

            // Process and render the report
            reportViewer.ServerReport.Refresh();

            //Render it to PDF and take the bytes to the FileStream
            bytes = reportViewer.ServerReport.Render(
                "PDF", null, out mimeType, out encoding, out filenameExtension,
                out streamids, out warnings);

            fs = new FileStream(Path.Combine(exportPath, PDFfileName),FileMode.Create))
            fs.Write(bytes, 0, bytes.Length);
            success = true;
        }
        catch (Exception ex)
        {
            errorMsg = ex.Message;
            Console.Error.WriteLine(String.Format("Se presento error al generar extracto para la cuenta \"{0}\" de la fecha {1}-{2}", accountNumber, settlementDateTime, errorMsg));
        }
        finally
        {
            if(fs != null)
            {
                fs.Close(); 
            }
            if(reportViewer != null)
            {
                reportViewer.Dispose(); 
                reportViewer = null ;
            }
        }

        return success;
    }
}