Excel Interop: Quitting the Excel application instance makes my tests fail? - c#

I want to encapsulate the use of Excel Interop to make it easier to use somehow in a reuseable library.
So far, I have written some tests that work good altogether, except that between each test, I force Excel to quite so that it does have handle on the test file no more in order to be able to delete.
Once I quit the application instance between after each of my tests, Excel seems to be no longer responding, causing Windows to display
"Excel has stopped working and is looking for a solution"
message. This message lasts a few seconds, meanwhile Excel is closing, causing the hang on the file to occur and my tests to throw an exception like
"Cannot access file because it is being used by another process..."
message. Otherwise, each of my tests run individually just fine!
Any clue on how to solve this issue?
Do I overuse the ApplicationClass.Quit() method?
Quitting Excel only once the testing is through with my tests causes the files created for the tests purpose not to be deleteable.
Thanks! =)

If you've made changes to the Workbook then could it be the "Do you wish to save changes?" dialog which is holding things up. You could try setting the _Workbook.Saved property to True prior to quitting the application. See here for details

I was having the same "Cannot access file because it is being used by another process..." issue.
I was saving the worksheet, what you need to do is save the work book. Here's a full example.
private void TestCreateExcel(IEnumerable<Sales1> data)
{
var excelApp = new Excel.Application();
var workBook = excelApp.Workbooks.Add();
Excel._Worksheet workSheet = excelApp.ActiveSheet;
workSheet.Cells[1, "A"] = "Title";
workSheet.Cells[1, "B"] = "Author(s)";
workSheet.Cells[1, "C"] = "Release Date";
workSheet.Cells[1, "D"] = "Total Books Sold";
workSheet.Cells[1, "E"] = "Last 30 Days Sales";
workSheet.Cells[1, "F"] = "Average Sales Per Month";
workSheet.Cells[1, "G"] = "Starting Advance";
workSheet.Cells[1, "H"] = "Current Advance";
int index = 1; //Keep track of the which row we're writing to.
foreach (var n in data)
{
index++;
workSheet.Cells[index, "A"] = n.Title;
workSheet.Cells[index, "B"] = n.Author;
workSheet.Cells[index, "C"] = n.ReleaseDate.ToShortDateString();
workSheet.Cells[index, "D"] = n.TotalBooksSold;
workSheet.Cells[index, "E"] = n.Last30DaysSales;
workSheet.Cells[index, "F"] = n.AverageSalesPerMonth;
workSheet.Cells[index, "G"] = n.StartingAdvance;
workSheet.Cells[index, "H"] = n.CurrentAdvance;
}
workBook.SaveAs(Server.MapPath(filePath + fileName));
excelApp.Quit();
}

Related

Method in Service that uses excel isn't saving and doesn't appear to produce an exception

I have a problem with some code in a service I have. The method just creates a datatable of the report that needs to be created and then writes it to an existing excel file. The problem is that it fails at the save of the file. Somewhat more oddly, it doesn't appear to be catching errors, and I don't know why. I've included the code below. Of note:
excel.Visible=true; doesn't seem to make the excel sheet visible each time so I can't really watch what's going on in the excel itself. I assume it's not becoming visible because it's a service, but I don't really know.
I know that the datatable is producing output as I've had the log (Which is just a text file where I can write events and errors) writes both the cells value and it's location and it has never stopped in the Foreach loop or the for loop within it
I know that it's failing at the wb.Save(); because the Log.WriteLine("WriteTIByEmp 4"); successfully writes to the text file, but the Log.WriteLine("WriteTIByEmp 5"); does not.
The catch (Exception ex) also doesn't seem to be working, as it doesn't write anything about the exception but doesn't even write the Log.WriteLine("Catching Exception");, so I'm a bit lost.
Edit: Just to note, this is all using Interops in the excel portion. It's just that the "using Microsoft.Office.Interop.Excel" is declared at the top of the class to save time and typing as almost all the methods in this particular class are using excel. The excel file is always opening in this process, I can see it in the task manager, and I have had other methods successfully write to excel files in this process. Only this particular method has had issues.
public void WriteTIByEmp(CI.WriteReport Log)
{
try
{
System.Data.DataTable Emps = Pinpoint.TICardsByEmpStatsDaily.GetTICardsByEmployer();
Log.WriteLine("WriteTIByEmp 1");
Application excel = new Application();
excel.Visible = true;
Workbook wb = excel.Workbooks.Open(TIEMPPath);
Worksheet ws = wb.Worksheets[1];
ws.Range["A:G"].Clear();
Log.WriteLine("WriteTIByEmp 2");
int RowNum = 0;
int ColCount = Emps.Columns.Count;
Log.WriteLine("WriteTIByEmp 3");
foreach (DataRow dr in Emps.Rows)
{
RowNum++;
for (int i = 0; i < ColCount; i++)
{
ws.Cells[RowNum, i + 1] = dr[i].ToString();
Log.WriteLine("Cell Val:" + dr[i].ToString() + ". Cell Location: " + RowNum + "," + i);
}
}
Log.WriteLine("WriteTIByEmp 4");
wb.Save();
Log.WriteLine("WriteTIByEmp 5");
wb.Close();
Log.WriteLine("WriteTIByEmp 6");
excel = null;
Log.WriteLine("WriteTIByEmp 7");
}
catch (Exception ex)
{
Log.WriteLine("Catching Exception");
var st = new StackTrace(ex, true);
var frame = st.GetFrame(0);
var line = frame.GetFileLineNumber();
string msg = "Component Causing Error:" + ex.Source + System.Environment.NewLine + "Error Message: " + ex.Message + System.Environment.NewLine + "Line Number: " + line + System.Environment.NewLine + System.Environment.NewLine;
Log.WriteLine(msg, true);
}
}
Meaby try to use Interops
i don't understand how Your code can start Excel application
by this line :
Application excel = new Application();
try this
Microsoft.Office.Interop.Excel.Application xlexcel;
xlexcel = new Microsoft.Office.Interop.Excel.Application();
xlexcel.Visible = true;
I have been in similar situation.
Note: While using Interop Excel is a dependency as well as other processes accessing the file could cause issues. Therefore, I recommend using EPPlus Nuget Package as it works wonders.
https://www.nuget.org/packages/EPPlus/
Please refer to the below sample code.
FileInfo fi = new FileInfo(ExcelFilesPath + "myExcelFile.xlsx");
using (ExcelPackage pck = new ExcelPackage())
{
// Using Existing WorkSheet 1.
ExcelWorksheet ws = pck.Workbook.Worksheets[1];
// Loading Data From DataTable Called dt.
ws.Cells["A1"].LoadFromDataTable(dt, true);
// If you want to enable auto filter
ws.Cells[ws.Dimension.Address].AutoFilter = true;
// Some Formatting
Color colFromHex = System.Drawing.ColorTranslator.FromHtml("#00B388");
ws.Cells[ws.Dimension.Address].Style.Fill.PatternType = ExcelFillStyle.Solid;
ws.Cells[ws.Dimension.Address].Style.Fill.BackgroundColor.SetColor(colFromHex);
ws.Cells[ws.Dimension.Address].Style.Font.Color.SetColor(Color.White);
ws.Cells[ws.Dimension.Address].Style.Font.Bold = true;
ws.Cells["D:K"].Style.Numberformat.Format = "0";
ws.Cells["M:N"].Style.Numberformat.Format = "mm-dd-yyyy hh:mm:ss";
ws.Cells[ws.Dimension.Address].AutoFitColumns();
pck.SaveAs(fi);
}
You can refer to the above code from my project. I am loading the DataTable data into my excel file by providing the Range or Starting Cell.
I had found the issue. The Excel file was open on someone else's computer which resulted in it not being able to save the file, but it couldn't display the excel popup because excel wouldn't become visible (I still don't know why but Probably something to do with it being a service). So it just couldn't save but it wasn't a code error so it didn't show up in the log and couldn't continue so the code was just stuck. I'll make a copy for the purposes of updating in the future.

Does matter COM object not assigned to var is not released?

Will be all unmanaged COM objects released in case if I use code like this
var worksheet = new Application().Workbooks.Add().Worksheets.Add();
Marshal.ReleaseComObject(worksheet);
instead of code like this
var excel = new Application();
var workbook = excel.Workbooks.Add();
var worksheet = workbook.Worksheets.Add();
Marshal.ReleaseComObject(excel);
Marshal.ReleaseComObject(workbook);
Marshal.ReleaseComObject(worksheet);
?
If there is some documentation please send a link in answer.
Actually, both code samples will leave an Excel process running in the background. You need to call Application.Quit() on the application object, for example. The following works:
private static void DoExcel()
{
var application = new Application();
var workbook = application.Workbooks.Add();
var worksheet = workbook.Worksheets.Add();
// Name that this will be saved as
string name = workbook.FullName + ".xlsx";
string fullPath = Path.Combine(Directory.GetCurrentDirectory(), name);
// If a file of the same name exists, delete it so that we won't be prompted if
// we want to overwrite it when we save
if (File.Exists(fullPath))
File.Delete(fullPath);
// Save the workbook - otherwise we may be prompted as to whether we want to save when we go to quit
workbook.Save();
// Quit the application
application.Quit();
// Release the references
Marshal.ReleaseComObject(worksheet);
Marshal.ReleaseComObject(workbook);
Marshal.ReleaseComObject(application);
// Release the .NET reference and run the garbage collector now to make sure the application is closed immediately
worksheet = null;
GC.Collect();
GC.WaitForPendingFinalizers();
}
A few other good things to remember: I didn't use it here, but there's a Marshal.FinalReleaseComObject method that's very useful in these cases. Also, again I didn't use this in my code sample, but the Marshal.ReleaseComObject method returns the current count, so you could always do the release in a loop if you wanted to make sure the count reached zero:
while (Marshal.ReleaseComObject(comObject) > 0) { }
You can also use this for debugging purposes - e.g.
int count = Marshal.ReleaseComObject(comObject);
Trace.TraceInformation("Current COM object reference count: " + count.ToString());

Working with C# and Excel Interop

I have this code:
Microsoft.Office.Interop.Excel.Application xla = new Microsoft.Office.Interop.Excel.Application();
xla.Visible = false;
Workbook wb = xla.Workbooks.Add(XlSheetType.xlWorksheet);
Worksheet ws = (Worksheet)xla.ActiveSheet;
ws.Name = "Serial";
int i = 1;
foreach (DataRow comp in dsView.Tables[0].Rows)
{
ws.Cells[i, 1] = "'" + comp[0].ToString();
ws.Cells[i, 2] = "'" + comp[1].ToString();
ws.Cells[i, 3] = "'" + comp[2].ToString();
i++;
}
if (File.Exists(#"d:\DDD.xlsx"))
File.Delete(#"d:\DDD.xlsx");
xla.Save(#"d:\DDD.xlsx"); ---->>>> on this line i get the error
The error:
Exception from HRESULT: 0x800A03EC
I am working on C# winforms with Office 2012
Your problem is that the variable xla is your excel application and not a workbook. You want to save the workbook.
so
xla.Save(#"d:\DDD.xlsx"); ---->>>> on this line i get the error
should be
wb.SaveAs(#"d:\DDD.xlsx", System.Reflection.Missing.Value,System.Reflection.Missing.Value,System.Reflection.Missing.Value,
System.Reflection.Missing.Value,System.Reflection.Missing.Value,Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange,System.Reflection.Missing.Value,
System.Reflection.Missing.Value,System.Reflection.Missing.Value,System.Reflection.Missing.Value,System.Reflection.Missing.Value);
When I run Excel.Application.Save() with Visual Studio 2010 and Excel 2010 interop (Office 14) targeting .NET 4, it displays a dialog to select a location to save the file. Clicking Cancel on that dialog results in a COM exception. But clicking Save has odd results: When I supply a valid file path and name as a parameter like Excel.Application.Save(#"C:\blah.xlsx"), I end up with two files saved. The first is named Sheet1.xlsx and contains what I'd expect, even though I didn't choose that name in the dialog. The other is named blah.xlsx (as per my file name parameter) and won't open correctly in Excel. If I call Excel.Application.Save() without a file name as a parameter, a valid file is saved with the name and path I selected in the dialog, but I also get a "RESUME.XLW" file as well. So it seems that the Application.Save method may not be a good choice to use. Instead, you can do something like this, which works as you'd expect:
using System;
using Excel = Microsoft.Office.Interop.Excel;
namespace WindowsFormsApplication2
{
static class Program
{
static void Main()
{
Excel.Application xlApp = new Excel.Application();
Excel.Workbook book = xlApp.Workbooks.Add(Excel.XlSheetType.xlWorksheet);
Excel.Worksheet sheet = book.ActiveSheet;
sheet.Name = "Booya";
Excel.Range range = sheet.Cells[1, 1];
range.Value = "This is some text";
book.SaveAs(#"C:\blah.xlsx");
}
}
}

Runtime Error - Export Excel using C# from IIS

When I run on debugging mode on my local machine, there is no problems. I can export to excel...
private void ExportToExcel(string str)
{
_Excel.Application oXL;
_Excel.Workbook oWB;
_Excel.Worksheet oSheet;
_Excel.Range oRange;
// Start Excel and get Application object.
oXL = new _Excel.Application();
// Set some properties
oXL.Visible = true;
oXL.DisplayAlerts = false;
// Get a new workbook.
oWB = oXL.Workbooks.Add(Missing.Value);
// Get the active sheet
oSheet = (_Excel.Worksheet)oWB.ActiveSheet;
oSheet.Name = "PO_Status";
// Process the DataTable
int rowCount = 1;
foreach (DataRow dr in dtStatus(str).Rows)
{
rowCount += 1;
for (int i = 1; i < dtStatus(str).Columns.Count + 1; i++)
{
// Add the header the first time through
if (rowCount == 2)
{
oSheet.Cells[1, i] = dtStatus(str).Columns[i - 1].ColumnName;
}
oSheet.Cells[rowCount, i] = dr[i - 1].ToString();
}
}
// Resize the columns
oRange = oSheet.get_Range(oSheet.Cells[1, 1],
oSheet.Cells[rowCount, dtStatus(str).Columns.Count]);
oRange.EntireColumn.AutoFit();
try
{
// Save the sheet and close
oSheet = null;
oRange = null;
oWB.SaveAs("POStatus.xls", _Excel.XlFileFormat.xlWorkbookNormal,
Missing.Value, Missing.Value, Missing.Value, Missing.Value,
_Excel.XlSaveAsAccessMode.xlExclusive,
Missing.Value, Missing.Value, Missing.Value,
Missing.Value, Missing.Value);
//oWB.Close(Missing.Value, Missing.Value, Missing.Value);
//oWB = null;
//oXL.Quit();
// Clean up
// NOTE: When in release mode, this does the trick
GC.WaitForPendingFinalizers();
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
}
catch (Exception ex)
{
Session["error"] = ex.Message;
Response.Redirect("MessageBoard.aspx");
}
}
private DataTable dtStatus(string str)
{
DataTable dt = new DataTable();
SqlCommand cmd = new SqlCommand(#"Select " + str + ""
+ " From tbl_RFI Full Join"
+ " tbl_RFQ On tbl_RFI.RFINo = tbl_RFQ.RFINo Full Join"
+ " tbl_NNB On tbl_RFQ.RFQNo = tbl_NNB.RFQNo Full Join"
+ " tbl_PO On tbl_PO.NNBNo = tbl_NNB.NNBNo"
+ " Where tbl_RFI.JobNo = '" + ddlJobNo.SelectedValue.ToString().Trim() + "'", connPMis);
SqlDataAdapter adp = new SqlDataAdapter(cmd);
adp.Fill(dt);
return dt;
}
}
But when I run on IIS, it's not working... I got error message like this
Runtime Error
Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.
Details: To enable the details of this specific error message to be viewable on remote machines, please create a tag within a "web.config" configuration file located in the root directory of the current web application. This tag should then have its "mode" attribute set to "Off".
Notes: The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's configuration tag to point to a custom error page URL.
My Server is Windows Server 2008/ IIS7
thx for your help
Excel needs to be installed on the server for this to work.
An alternative way to see the full exception is if you have access to the server desktop, you can navigate to your page from the server and because it is local you'll get the full stack trace.
This is an expressly discouraged approach to working with Excel on the server, says Microsoft: http://support.microsoft.com/kb/257757. The preferred approach is to work with a library/dll that can read and/or manipulate xls and xlsx files without launching and automating some other application. There are free libraries, like NPOI, and commercial products like SpreadsheetGear and Aspose. You have a lot more options if you limit usage to xlsx.
If you DO use this interop approach:
a. You need to more carefully assign all items to variables for later cleanup. For example, each time you do oSheet.Cells[1, i] in a loop, you leak a cell reference.
b. Each resource that you assign must be cleaned up by calling Marshal.ReleaseComObject(theVariable) when you are through with it. THESE THINGS ARE NOT GARBAGE COLLECTED, so GC.Anything will have no effect.
c. Your try…catch redirects without cleaning up any resources that were acquired before the exception or closing Excel, which means every time an exception is encountered in this method, you are liable to have a phantom Excel instance running in the background. You'll probably need to use try…catch…finally and do all of your cleanup in the finally block.
go into your application and in your web.config and change your <customErrors element to mode="Off" and try again and post the real error message here. The other thing you can do is login to the IIS machine and run it there and see the full error message.
It could be be permissions in saving the excel file, or it could be an error launching excel but we need to see the error message here. Make sure that the location you are saving the file to has permissions to the Network Service account (or whatever account you happen to have your application running under as its app pool account in iis)
See the following link for many many other (better) ways of doing this.
Create Excel (.XLS and .XLSX) file from C#

Excel Template: Merging data and saving workbooks

I am on my first foray into Excel Interop and after a flying start have hit a wall.
I have an Excel template that contains one sheet which is an assessment form and another which contains guidance notes for how to carry out the assessment.
I also have an XML file with the details of the projects being assessed.
I need to merge the project title, application number and company name into the first sheet and then save the sheet with the filename [Application No] - [Project Title].xlsx.
The first part is working fine. I have Loaded the XML and the code is putting the data into the form where it should be.
My problem is the saving part. I found the .SaveAs method and it creates a couple of files... but they won't open. I then get a HRESULT error 0x800A03EC - Searching the web has explained nothing about this. Something is telling me that this.SaveAs() is referring to the worksheet rather than the work book but I am just guessing there.
I am hoping I have done something stupid and it is an easy fix.
For reference here is my code but like I say I am not sure how useful it is.
private void MergeData()
{
doc.Load(#"C:\XML Data\source.xml");
XmlNodeList forms = doc.SelectNodes("//form1");
for (int i = 0; i < forms.Count; i++)
{
XmlNodeList nodes = forms[i].ChildNodes;
string refNo = nodes[0].InnerText.ToString();
string companyName = nodes[3].InnerText.ToString();
string title = nodes[1].InnerText.ToString();
this.Cells[9, 4] = title;
this.Cells[11, 4] = refNo;
this.Cells[14, 4] = companyName;
this.SaveAs(#"C:\Assessment Forms\" + refNo + " - " + title + ".xlsx");
}
}
Does anyone know how to save these files?
Thanks for reading
EDIT--
I have found this article
C# and Excel Interop issue, Saving the excel file not smooth
and changed the code to include its suggestion
Excel.Application app = this.Application;
Excel.Workbook wb = app.Workbooks.Add(missing);
wb.SaveAs(#"C:\Assessment Forms\" + refNo + " - " + title + ".xlsx");
But it is doing the same.
I am on a deadline so think I am going to have to start copying, pasting and saving manually :(
Not sure what object this is here, but if you are correct in assuming this is a worksheet, try this.Parent.SaveAs
Alternatively if this turns out to be a range, try this.Worksheet.Parent.SaveAs

Categories