Excel open 3 times and wont close until i use the task manag

Im pretty new to the C# language. Right now im writing a Programm to calculate different

cable dimensioning. Till now everything just worked fine, but now i realised that when i use the programm it opens me three times the excel process and will only close if i propperly close the programm. otherwise everytime i hit the calculate button it will add 3 more excel process to the allready 3. I'm using excel for all the constants i need for my calculation. I just cant find out where the Problem is so i thought you might help me.

I know the style of my programming isnt very good even bad:-) but im no programmer and most of the stuff i have in my programm is from the internet, because im an newby and dont know or understand some of that.

So if you could help me finding the error i would be very thankfull. The comments and other stuff is written in german, because thats my nativ language i hope this wont be a problem. I guess the error is because im trying befor i open the excel file to catch all possible exceptions with if and else.

thank you

Ok i solved the Problem by my self. At first i had to remove some of my open Excel function. Actually i opend the Excel 3 times in the Programm on different positions. so i just cut it together to one (i actually only needed two befor the third one was a mistake:-) ) But still i had the Problem, that the excel operation wouldnt stop by it self and everytime i hit the calculate button one more excel showed up in the Taskmanager. So i searched the internet and found this:

Open Excel:

var ExcelApp = new Microsoft.Office.Interop.Excel.Application();
var workbook = ExcelApp.Workbooks.Open(myPath);
var worksheet = workbook.ActiveSheet as Worksheet;

then do stuff in it...

And closing Excel again:

workbook.Save();
workbook.Close();
ExcelApp.Quit();
Marshal.ReleaseComObject(ExcelApp);
Marshal.ReleaseComObject(workbook);

workbook = null;
worksheet = null;
ExcelApp = null;

GC.GetTotalMemory(false);
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
GC.GetTotalMemory(true);

with this Method one Excel operation is open as long as the Programm is running, but everytime i hit the calculate button now an excel operation opens but closes right after it is done. Its not perfect but it will work like this:-)

1 Reply

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Sam Urai10y ago
Ok i solved the Problem by my self. At first i had to remove some of my open Excel function. Actually i opend the Excel 3 times in the Programm on different positions. so i just cut it together to one (i actually only needed two befor the third one was a mistake:-) ) But still i had the Problem, that the excel operation wouldnt stop by it self and everytime i hit the calculate button one more excel showed up in the Taskmanager. So i searched the internet and found this:
Open Excel:
var ExcelApp = new Microsoft.Office.Interop.Excel.Application();
var workbook = ExcelApp.Workbooks.Open(myPath);
var worksheet = workbook.ActiveSheet as Worksheet;
then do stuff in it...
And closing Excel again:
workbook.Save();
workbook.Close();
ExcelApp.Quit();
Marshal.ReleaseComObject(ExcelApp);
Marshal.ReleaseComObject(workbook);

workbook = null;
worksheet = null;
ExcelApp = null;

GC.GetTotalMemory(false);
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
GC.GetTotalMemory(true);
with this Method one Excel operation is open as long as the Programm is running, but everytime i hit the calculate button now an excel operation opens but closes right after it is done. Its not perfect but it will work like this:-)