[c#] Closing Excel Application Process in C# after Data Access

I'm writing an application in C# that opens an Excel template file for read/write operations. I want to when user closes the application, excel application process has been closed, without saving excel file. See my Task Manager after multiple runs of the app.

I use this code to open the excel file :

public Excel.Application excelApp = new Excel.Application();
public Excel.Workbook excelBook;
excelBook = excelApp.Workbooks.Add(@"C:/pape.xltx");

and for data access I use this code :

Excel.Worksheet excelSheet = (Worksheet)(excelBook.Worksheets[1]);
excelSheet.DisplayRightToLeft = true;
Range rng;
rng = excelSheet.get_Range("C2");
rng.Value2 = txtName.Text;

I see similar questions in stackoverflow such as this question and this, and test answers, but it doesn't works.

Based on another solutions. I have use this:

IntPtr xAsIntPtr = new IntPtr(excelObj.Application.Hwnd);
excelObj.ActiveWorkbook.Close();

System.Diagnostics.Process[] process = System.Diagnostics.Process.GetProcessesByName("Excel");
                foreach (System.Diagnostics.Process p in process)
                {
                    if (p.MainWindowHandle == xAsIntPtr)
                    {
                        try
                        {
                            p.Kill();
                        }
                        catch { }
                    }
                }

Using the "MainWindowHandle" to identify the process and close him.

excelObj: This is my Application Interop excel objecto

I have found that it is important to have Marshal.ReleaseComObject within a While loop AND finish with Garbage Collection.

static void Main(string[] args)
{
    Excel.Application xApp = new Excel.Application();
    Excel.Workbooks xWbs = xApp.Workbooks;
    Excel.Workbook xWb = xWbs.Open("file.xlsx");

    Console.WriteLine(xWb.Sheets.Count);

    xWb.Close();
    xApp.Quit();

    while (Marshal.ReleaseComObject(xWb) != 0);
    while (Marshal.ReleaseComObject(xWbs) != 0);
    while (Marshal.ReleaseComObject(xApp) != 0);

    GC.Collect();
    GC.WaitForPendingFinalizers();
}

xlBook.Save();
xlBook.Close(true);
xlApp.Quit();
System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp);

try this.. it worked for me... you should release that xl application object to stop the process.

Think of this, it kills the process:

System.Diagnostics.Process[] process=System.Diagnostics.Process.GetProcessesByName("Excel");
foreach (System.Diagnostics.Process p in process)
{
    if (!string.IsNullOrEmpty(p.ProcessName))
    {
        try
        {
            p.Kill();
        }
        catch { }
    }
}

Also, did you try just close it normally?

myWorkbook.SaveAs(@"C:/pape.xltx", missing, missing, missing, missing, missing, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, missing, missing, missing, missing, missing);
excelBook.Close(null, null, null);                 // close your workbook
excelApp.Quit();                                   // exit excel application
excel = null;                                      // set to NULL

Killing Excel is not always easy; see this article: 50 Ways to Kill Excel

This article takes the best advice from Microsoft (MS Knowlege Base Article) on how to get Excel to quit nicely, but then also makes sure about it by killing the process if necessary. I like having a second parachute.

Make sure to Close any open workbooks, Quit the application and Release the xlApp object. Finally check to see if the process is still alive and if so then kill it.

This article also makes sure that we don't kill all Excel processes but only kills the exact process that was started.

See also Get Process from Window Handle

Here is the code I use: (works every time)

Sub UsingExcel()

    'declare process; will be used later to attach the Excel process
    Dim XLProc As Process

    'call the sub that will do some work with Excel
    'calling Excel in a separate routine will ensure that it is 
    'out of scope when calling GC.Collect
    'this works better especially in debug mode
    DoOfficeWork(XLProc)

    'Do garbage collection to release the COM pointers
    'http://support.microsoft.com/kb/317109
    GC.Collect()
    GC.WaitForPendingFinalizers()

    'I prefer to have two parachutes when dealing with the Excel process
    'this is the last answer if garbage collection were to fail
    If Not XLProc Is Nothing AndAlso Not XLProc.HasExited Then
        XLProc.Kill()
    End If

End Sub

'http://msdn.microsoft.com/en-us/library/ms633522%28v=vs.85%29.aspx
<System.Runtime.InteropServices.DllImport("user32.dll", SetLastError:=True)> _
    Private Shared Function GetWindowThreadProcessId(ByVal hWnd As IntPtr, _
    ByRef lpdwProcessId As Integer) As Integer
End Function

Private Sub ExcelWork(ByRef XLProc As Process)

    'start the application using late binding
    Dim xlApp As Object = CreateObject("Excel.Application")

    'or use early binding
    'Dim xlApp As Microsoft.Office.Interop.Excel

    'get the window handle
    Dim xlHWND As Integer = xlApp.hwnd

    'this will have the process ID after call to GetWindowThreadProcessId
    Dim ProcIdXL As Integer = 0

    'get the process ID
    GetWindowThreadProcessId(xlHWND, ProcIdXL)

    'get the process
    XLProc = Process.GetProcessById(ProcIdXL)


    'do some work with Excel here using xlApp

    'be sure to save and close all workbooks when done

    'release all objects used (except xlApp) using NAR(x)


    'Quit Excel 
    xlApp.quit()

    'Release
    NAR(xlApp)

End Sub

Private Sub NAR(ByVal o As Object)
    'http://support.microsoft.com/kb/317109
    Try
        While (System.Runtime.InteropServices.Marshal.ReleaseComObject(o) > 0)
        End While
    Catch
    Finally
        o = Nothing
    End Try
End Sub

You may kill process with your own COM object excel pid

add somewhere below dll import code

[DllImport("user32.dll", SetLastError = true)]
private static extern int GetWindowThreadProcessId(IntPtr hwnd, ref int lpdwProcessId);

and use

 if (excelApp != null)
            {
                int excelProcessId = -1;
                GetWindowThreadProcessId(new IntPtr(excelApp.Hwnd), ref excelProcessId);

                Process ExcelProc = Process.GetProcessById(excelProcessId);
                if (ExcelProc != null)
                {
                    ExcelProc.Kill();
                }
            }

excelBook.Close(); excelApp.Quit(); add end of the code, it could be enough. it is working on my code

We can close the Excel Application while converting xls to xlsx by using following code. When we perform this kind of task then Excel application is running in task manager, we Should close this excel which is running in background. Interop is a Com component ,to release the com component we used Marshal.FinalReleaseComObject.

 private void button1_Click(object sender, EventArgs e)
    {

        Excel03to07("D:\\TestExls\\TestExcelApp.XLS");

    }
    private void Excel03to07(string fileName)
    {
        string svfileName = Path.ChangeExtension(fileName, ".xlsx");
        object oMissing = Type.Missing;
        var app = new Microsoft.Office.Interop.Excel.Application();
        var wb = app.Workbooks.Open(fileName, oMissing, oMissing,
                        oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing);
        wb.SaveAs(svfileName, XlFileFormat.xlOpenXMLWorkbook, Type.Missing, Type.Missing, Type.Missing, Type.Missing, XlSaveAsAccessMode.xlNoChange, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);

        wb.Close(false, Type.Missing, Type.Missing);
        app.Quit();
        GC.Collect();
        Marshal.FinalReleaseComObject(wb);
        Marshal.FinalReleaseComObject(app);
   }

private void releaseObject(object obj)
{
    try
    {
        System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
        obj = null;
    }
    catch (Exception ex)
    {
        obj = null;
        MessageBox.Show("Unable to release the Object " + ex.ToString());
    }
    finally
    {
        GC.Collect();
    }
}

Use a variable for each Excel object and must loop Marshal.ReleaseComObject >0. Without the loop, Excel process still remain active.

public class test{
        private dynamic ExcelObject;
        protected dynamic ExcelBook;
        protected dynamic ExcelBooks;
        protected dynamic ExcelSheet;

public void LoadExcel(string FileName)
        {
            Type t = Type.GetTypeFromProgID("Excel.Application");
            if (t == null) throw new Exception("Excel non installato");
            ExcelObject = System.Activator.CreateInstance(t);
            ExcelObject.Visible = false;
            ExcelObject.DisplayAlerts = false;
            ExcelObject.AskToUpdateLinks = false;
            ExcelBooks = ExcelObject.Workbooks;
            ExcelBook = ExcelBooks.Open(FileName,0,true);
            System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application");
            ExcelSheet = ExcelBook.Sheets[1];
        }
 private void ReleaseObj(object obj)
        {
            try
            {
                int i = 0;
             while(   System.Runtime.InteropServices.Marshal.ReleaseComObject(obj) > 0)
                {
                    i++;
                    if (i > 1000) break;
                }
                obj = null;
            }
            catch 
            {
                obj = null;
            }
            finally
            {
                GC.Collect();
            }
        }
        public void ChiudiExcel() {
            System.Threading.Thread.CurrentThread.CurrentCulture = ci;

            ReleaseObj(ExcelSheet);
            try { ExcelBook.Close(); } catch { }
            try { ExcelBooks.Close(); } catch { }
            ReleaseObj(ExcelBooks);
            try { ExcelObject.Quit(); } catch { }
            ReleaseObj(ExcelObject);
        }
}

Most of the methods works, but the excel process always stay until close the appliation.

When kill excel process once it can't be executed once again in the same thread - don't know why.

         wb.Close();
         app.Quit();

         System.Diagnostics.Process[] process = System.Diagnostics.Process.GetProcessesByName("Excel");
         foreach (System.Diagnostics.Process p in process)
         {
             if (!string.IsNullOrEmpty(p.ProcessName) && p.StartTime.AddSeconds(+10) > DateTime.Now)
             {
                 try
                 {
                     p.Kill();
                 }
                 catch { }
             }
         }

It Closes last 10 sec process with name "Excel"

Ref: https://stackoverflow.com/a/17367570/132599

Avoid using double-dot-calling expressions, such as this:

var workbook = excel.Workbooks.Open(/*params*/)

...because in this way you create RCW objects not only for workbook, but for Workbooks, and you should release it too (which is not possible if a reference to the object is not maintained).

This resolved the issue for me. Your code becomes:

public Excel.Application excelApp = new Excel.Application();
public Excel.Workbooks workbooks;
public Excel.Workbook excelBook;
workbooks = excelApp.Workbooks;
excelBook = workbooks.Add(@"C:/pape.xltx");

...

Excel.Sheets sheets = excelBook.Worksheets;
Excel.Worksheet excelSheet = (Worksheet)(sheets[1]);
excelSheet.DisplayRightToLeft = true;
Range rng;
rng = excelSheet.get_Range("C2");
rng.Value2 = txtName.Text;

And then release all those objects:

System.Runtime.InteropServices.Marshal.ReleaseComObject(rng);
System.Runtime.InteropServices.Marshal.ReleaseComObject(excelSheet);
System.Runtime.InteropServices.Marshal.ReleaseComObject(sheets);
excelBook .Save();
excelBook .Close(true);
System.Runtime.InteropServices.Marshal.ReleaseComObject(xlBook);
System.Runtime.InteropServices.Marshal.ReleaseComObject(workbooks);
excelApp.Quit();
System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp);

I wrap this in a try {} finally {} to ensure everything gets released even if something goes wrong (what could possibly go wrong?) e.g.

public Excel.Application excelApp = null;
public Excel.Workbooks workbooks = null;
...
try
{
    excelApp = new Excel.Application();
    workbooks = excelApp.Workbooks;
    ...
}
finally
{
    ...
    if (workbooks != null) System.Runtime.InteropServices.Marshal.ReleaseComObject(workbooks);
    excelApp.Quit();
    System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp);
}

The right way to close all excel process

var _excel = new Application();
foreach (Workbook _workbook in _excel.Workbooks) {
    _workbook.Close(0);
}

_excel.Quit();
_excel = null;

Using process example, this may close all the excel process regardless.

var process = System.Diagnostics.Process.GetProcessesByName("Excel");
foreach (var p in process) {
    if (!string.IsNullOrEmpty(p.ProcessName)) {
        try {
            p.Kill();
        } catch { }
    }
}

        GetWindowThreadProcessId((IntPtr)app.Hwnd, out iProcessId);
        wb.Close(true,Missing.Value,Missing.Value);
        app.Quit();
        System.Diagnostics.Process[] process = System.Diagnostics.Process.GetProcessesByName("Excel");
        foreach (System.Diagnostics.Process p in process)
        {
            if (p.Id == iProcessId)
            {
                try
                {
                    p.Kill();
                }
                catch { }
            }
        }
}
[DllImport("user32.dll")]

private static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);

uint iProcessId = 0;

this GetWindowThreadProcessId finds the correct Process Id o excell .... After kills it.... Enjoy It!!!

workbook.Close(0);
excelApp.Quit();

Worked for me.

I met the same problems and tried many methods to solve it but doesn't work. Finally , I found the by my way. Some reference enter link description here

Hope my code can help someone future. I have been spent more than two days to solve it. Below is my Code:

//get current in useing excel
            Process[] excelProcsOld = Process.GetProcessesByName("EXCEL");
            Excel.Application myExcelApp = null;
            Excel.Workbooks excelWorkbookTemplate = null;
            Excel.Workbook excelWorkbook = null;
try{
    //DO sth using myExcelApp , excelWorkbookTemplate, excelWorkbook
}
catch (Exception ex ){
}
finally
            {
                //Compare the EXCEL ID and Kill it 
                Process[] excelProcsNew = Process.GetProcessesByName("EXCEL");
                foreach (Process procNew in excelProcsNew)
                {
                    int exist = 0;
                    foreach (Process procOld in excelProcsOld)
                    {
                        if (procNew.Id == procOld.Id)
                        {
                            exist++;
                        }
                    }
                    if (exist == 0)
                    {
                        procNew.Kill();
                    }        
                }
            }