Zipping a folder - delphi

Question

I am trying to use
TZipFile.ZipDirectoryContents()
Like so:
TZipFile.ZipDirectoryContents('Test.PCF', WorkingDir);
If I am reading this right, it should save the contents of folder "workingdir" into a file named Test.pcf.
Now when I do this I get error::
Raised exception class EFOpenError with message Cannot open file
...test.pcf. The process cannot access the file because its being used by another process."
Two things confuse me:
It says that it cannot open file. There is no test.pcf yet. I was hoping this would create it.
It says cannot access file. Is this because it's not created yet? Am I using this function wong? If so how would I create a zip file from a folder location?

Answer 1

I tested your code and it failed in the same way as you reported.
I then created an empty zip file manually by running WinZip.
Then ran your code and it ran fine.
It appears that the zip file has to already exist for ZipDirectoryContents to work.
To create a zip file programatically:
myZipFile := TZIpFile.Create;
myZipFile.Open('c:\myfolder\newzipfile.zip', TZipMode.zmWrite);
myZipFile.Close;
myZipFile.Free;
This line will then work:
TZipFile.ZipDirectoryContents('c:\myfolder\newzipfile.zip', WorkingDir);