Application not quitting after calling quit
None of the above recommendations worked for me until I followed @SiddharthRout's comment above. "As of today, what is the right way to work with COM objects?"
It points out that com object references are kept alive under the debugger. A work-around is to call GC from the procedure that calls the com procedure. It worked for me.
Run GC from Finally in a TRY Catch block.
copied from:post by "Govert" on what is the right way to work with COM objects?
using System;
using System.Runtime.InteropServices;
using Microsoft.Office.Interop.Excel;
namespace TestCsCom
{
Class Program
{
static void Main(string[] args)
{
// NOTE: Don't call Excel objects in here...
// Debugger would keep alive until end, preventing GC cleanup
// Call a separate function that talks to Excel
DoTheWork();
// Now let the GC clean up (repeat, until no more)
do
{
GC.Collect();
GC.WaitForPendingFinalizers();
}
while (Marshal.AreComObjectsAvailableForCleanup());
}
static void DoTheWork()
{
Application app = new Application();
Workbook book = app.Workbooks.Add();
Worksheet worksheet = book.Worksheets["Sheet1"];
app.Visible = true;
for (int i = 1; i <= 10; i++) {
worksheet.Cells.Range["A" + i].Value = "Hello";
}
book.Save();
book.Close();
app.Quit();
// NOTE: No calls the Marshal.ReleaseComObject() are ever needed
}
}
}
I have used the ability to close a EXCEL Document in script many times along with hiding making visible and now closing if it's the only workbook open else close this worksheet. Here is my
Sub ExitWorkBook()
Dim wb As Workbook
Dim c As Integer
c = 0
For Each wb In Application.Workbooks
c = c + 1
Next wb
If c = 1 Then
Application.Quit '--Quit this worksheet but keep excel open.
Else
Workbooks("(excel workbook name).xls").Close '-- Close Excel
End If
'
End Sub
Just Calling .Quit() will not remove the Application from memory. It is very important to close the objects after you are done with your coding. This ensures that all objects are released properly and nothing remains in the memory.
See this example
Imports Excel = Microsoft.Office.Interop.Excel
Public Class Form1
'~~> Define your Excel Objects
Dim xlApp As New Excel.Application
Dim xlWorkBook As Excel.Workbook
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'~~> Add a New Workbook
xlWorkBook = xlApp.Workbooks.Add
'~~> Display Excel
xlApp.Visible = True
'~~> Do some stuff Here
'~~> Save the file
xlWorkBook.SaveAs(Filename:="C:\Tutorial\SampleNew.xlsx", FileFormat:=51)
'~~> Close the File
xlWorkBook.Close()
'~~> Quit the Excel Application
xlApp.Quit()
'~~> Clean Up
releaseObject (xlApp)
releaseObject (xlWorkBook)
End Sub
'~~> Release the objects
Private Sub releaseObject(ByVal obj As Object)
Try
System.Runtime.InteropServices.Marshal.ReleaseComObject (obj)
obj = Nothing
Catch ex As Exception
obj = Nothing
Finally
GC.Collect()
End Try
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Me.Close()
End Sub
End Class
Also worth mentioning is the 2 DOT Rule.
If you love automating Excel from VB.Net then you might also want to have a look at this link.
FOLLOWUP
The problem is the 2 DOT Rule as I mentioned above. When you use the 2 DOT Rule (Ex: Excel.XlBordersIndex.xlDiagonalDown) then you have to do the Garbage Collection by using GC.Collect(). So All you need to do is add this part
Finally
GC.Collect()
in the Private Sub ReleaseObject(ByVal obj As Object)
Private Sub ReleaseObject(ByVal obj As Object)
Try
Dim intRel As Integer = 0
Do
intRel = System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
Loop While intRel > 0
MsgBox("Final Released obj # " & intRel)
Catch ex As Exception
MsgBox("Error releasing object" & ex.ToString)
obj = Nothing
Finally
GC.Collect()
End Try
End Sub
FINAL CODE
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim xlApp As New excel.Application
Dim xlWorkBook As excel.Workbook
Dim xlWorkSheet As excel.Worksheet
Dim xlRange As excel.Range
'Dim misValue As Object = System.Reflection.Missing.Value
xlWorkBook = xlApp.Workbooks.Add
xlWorkSheet = DirectCast(xlWorkBook.Sheets("sheet1"), excel.Worksheet)
xlApp.Visible = True
Dim headers = (From ch In DataGridView1.Columns _
Let header = DirectCast(DirectCast(ch, DataGridViewColumn).HeaderCell, DataGridViewColumnHeaderCell) _
Select header.Value).ToArray()
Dim headerText() As String = Array.ConvertAll(headers, Function(v) v.ToString)
Dim items() = (From r In DataGridView1.Rows _
Let row = DirectCast(r, DataGridViewRow) _
Where Not row.IsNewRow _
Select (From cell In row.Cells _
Let c = DirectCast(cell, DataGridViewCell) _
Select c.Value).ToArray()).ToArray()
Dim table As String = String.Join(vbTab, headerText) & Environment.NewLine
For Each a In items
Dim t() As String = Array.ConvertAll(a, Function(v) v.ToString)
table &= String.Join(vbTab, t) & Environment.NewLine
Next
table = table.TrimEnd(CChar(Environment.NewLine))
Clipboard.SetText(table)
Dim alphabet() As Char = "abcdefghijklmnopqrstuvwxyz".ToUpper.ToCharArray
xlRange = xlWorkSheet.Range("B2:" & alphabet(headerText.Length) & (items.Length + 2).ToString)
xlRange.Select()
xlWorkSheet.Paste()
xlRange.Borders(excel.XlBordersIndex.xlDiagonalDown).LineStyle = excel.XlLineStyle.xlLineStyleNone
xlRange.Borders(excel.XlBordersIndex.xlDiagonalUp).LineStyle = excel.XlLineStyle.xlLineStyleNone
With xlRange.Borders(excel.XlBordersIndex.xlEdgeLeft)
.LineStyle = excel.XlLineStyle.xlContinuous
.ColorIndex = 1 'black
.TintAndShade = 0
.Weight = excel.XlBorderWeight.xlMedium
End With
With xlRange.Borders(excel.XlBordersIndex.xlEdgeTop)
.LineStyle = excel.XlLineStyle.xlContinuous
.ColorIndex = 1 'black
.TintAndShade = 0
.Weight = excel.XlBorderWeight.xlMedium
End With
With xlRange.Borders(excel.XlBordersIndex.xlEdgeBottom)
.LineStyle = excel.XlLineStyle.xlContinuous
.ColorIndex = 1 'black
.TintAndShade = 0
.Weight = excel.XlBorderWeight.xlMedium
End With
With xlRange.Borders(excel.XlBordersIndex.xlEdgeRight)
.LineStyle = excel.XlLineStyle.xlContinuous
.ColorIndex = 1 'black
.TintAndShade = 0
.Weight = excel.XlBorderWeight.xlMedium
End With
With xlRange.Borders(excel.XlBordersIndex.xlInsideVertical)
.LineStyle = excel.XlLineStyle.xlContinuous
.ColorIndex = 1 'black
.TintAndShade = 0
.Weight = excel.XlBorderWeight.xlThin
End With
With xlRange.Borders(excel.XlBordersIndex.xlInsideHorizontal)
.LineStyle = excel.XlLineStyle.xlContinuous
.ColorIndex = 1 'black
.TintAndShade = 0
.Weight = excel.XlBorderWeight.xlThin
End With
xlWorkBook.SaveAs(Filename:="C:\Users\Siddharth Rout\Desktop\Word1.xls", FileFormat:=56)
xlWorkBook.Close()
xlApp.Quit()
ReleaseObject(xlRange)
ReleaseObject(xlWorkSheet)
ReleaseObject(xlWorkBook)
ReleaseObject(xlApp)
End Sub
Private Sub ReleaseObject(ByVal obj As Object)
Try
Dim intRel As Integer = 0
Do
intRel = System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
Loop While intRel > 0
MsgBox("Final Released obj # " & intRel)
Catch ex As Exception
MsgBox("Error releasing object" & ex.ToString)
obj = Nothing
Finally
GC.Collect()
End Try
End Sub