问题
Question: Why won't the Excel process close while app is running? Please don't jump the gun and mark it duplicate. If you could show the change needed in the code I really appreciate it. Excel process closes nicely when I close the app. I researched this problem for last few day read several SO posts and tried several things but nothing is working except for calling process.kill which I prefer to avoid if possible.
Imports Microsoft.Office.Interop
Imports System.Runtime.InteropServices
Public Class Form1
Public Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim xlApp As Excel.Application
Dim xlWorkBook As Excel.Workbook
Dim misValue As Object
Dim xlWorkSheet As Excel.Worksheet
Try
''EXCEL CREATION/INITAILIAZATION
misValue = System.Reflection.Missing.Value
xlApp = New Microsoft.Office.Interop.Excel.Application()
If xlApp Is Nothing Then
MessageBox.Show("Excel is not properly installed!!")
xlApp = Nothing
End If
xlWorkBook = xlApp.Workbooks.Add(misValue)
''WRITE TO WORKSHEET
xlWorkSheet = TryCast(xlWorkBook.Sheets("sheet1"), Excel.Worksheet)
xlWorkSheet.Cells(1, 1) = "THIS"
xlWorkSheet.Cells(1, 2) = "IS"
xlWorkSheet.Cells(1, 3) = "A"
xlWorkSheet.Cells(1, 4) = "TEST"
''FORCEFULLY CAUSING ERROR, NOW THE EXCEL PROCESS HANGING IN TASK MANAGER
''xlWorkSheet.Cells(1, -1) = "ERROR LINE"
''SAVE WORKSHEET
Dim Name = DateTime.Now.ToString("s").Replace(":", "_")
Dim Dir = AppDomain.CurrentDomain.BaseDirectory & "Output\" & Name & "Output.xls"
xlApp.DisplayAlerts = False
xlWorkBook.CheckCompatibility = False
xlWorkBook.DoNotPromptForConvert = True
xlWorkBook.SaveAs(Dir, Excel.XlFileFormat.xlWorkbookNormal, Type.Missing, Type.Missing, Type.Missing, Type.Missing, _
Excel.XlSaveAsAccessMode.xlExclusive, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing)
xlWorkBook.Close(False)
xlApp.Quit()
misValue = Nothing
If Not IsNothing(xlWorkSheet) And System.Runtime.InteropServices.Marshal.IsComObject(xlWorkSheet) Then
System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorkSheet)
xlWorkSheet = Nothing
End If
If Not IsNothing(xlWorkBook) And System.Runtime.InteropServices.Marshal.IsComObject(xlWorkBook) Then
System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorkBook)
xlWorkBook = Nothing
End If
If Not IsNothing(xlApp) And System.Runtime.InteropServices.Marshal.IsComObject(xlApp) Then
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(xlApp)
xlApp = Nothing
End If
GC.Collect()
GC.WaitForPendingFinalizers()
Catch ex As Exception
Dim exMsg = ex.Message
End Try
End Sub
End Class
回答1:
Your issue is double dot reference in .net. Read here :https://msdn.microsoft.com/en-us/library/8bwh56xe(v=vs.110).aspx
so once you deconstruct
xlWorkBook = xlApp.Workbooks.Add(misValue)
as
xlWorkBooks = xlApp.Workbooks
xlWorkBook = xlWorkBooks.Add(misValue)
and then release it, you are all good.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Call doSomeWork()
GC.Collect()
End Sub
Private Sub doSomeWork()
Dim xlApp As Excel.Application
Dim xlWorkBook As Excel.Workbook
Dim xlWorkBooks As Excel.Workbooks '// Added new variable to avoid double dot.
Dim misValue As Object
Dim xlWorkSheet As Excel.Worksheet
Try
''EXCEL CREATION/INITAILIAZATION
misValue = System.Reflection.Missing.Value
xlApp = New Microsoft.Office.Interop.Excel.Application()
If xlApp Is Nothing Then
MessageBox.Show("Excel is not properly installed!!")
xlApp = Nothing
End If
xlWorkBooks = xlApp.Workbooks
xlWorkBook = xlWorkBooks.Add(misValue)
''WRITE TO WORKSHEET
xlWorkSheet = xlWorkBook.Sheets(1)
'xlWorkSheet = TryCast(sheets("sheet1"), Excel.Worksheet)
xlWorkSheet.Cells(1, 1) = "THIS"
xlWorkSheet.Cells(1, 2) = "IS"
xlWorkSheet.Cells(1, 3) = "A"
xlWorkSheet.Cells(1, 4) = "TEST"
''FORCEFULLY CAUSING ERROR, NOW THE EXCEL PROCESS HANGING IN TASK MANAGER
''xlWorkSheet.Cells(1, -1) = "ERROR LINE"
''SAVE WORKSHEET
Dim Name = DateTime.Now.ToString("s").Replace(":", "_")
Dim Dir = AppDomain.CurrentDomain.BaseDirectory & "Output\" & Name & "Output.xls"
xlApp.DisplayAlerts = False
xlWorkBook.CheckCompatibility = False
xlWorkBook.DoNotPromptForConvert = True
xlWorkBook.SaveAs("C:\temp\a.xls", Excel.XlFileFormat.xlWorkbookNormal, Type.Missing, Type.Missing, Type.Missing, Type.Missing, _
Excel.XlSaveAsAccessMode.xlExclusive, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing)
xlWorkBook.Close(False)
xlApp.Quit()
misValue = Nothing
Catch ex As Exception
End Try
End Sub
来源:https://stackoverflow.com/questions/41065018/why-wont-the-excel-process-close-while-app-is-running