How to read a file which is opened in c#?

Question

Possible Duplicate:
Read file which is in use?

I have an mvvp-wpf aplication.. And I use infragistics to read the file. When the file is open..and if I try to read the file through application I get an exception.

One way to solve this is ...ask user to close the file .

Is there any other solution ?

Thanks in advance !

Good question, but it looks like there's an answer already, see the link above. — Andy White, Feb 25 '11 at 16:25

score 3 · Answer 1 · answered Feb 25 '11 at 16:25

3

Try to open it with the least privileges, e.g. don't request an exclusive read or write lock.

answered Feb 25 '11 at 16:25

Daniel Hilgarth

171,043
40
335
443

score 1 · Answer 2 · answered Feb 25 '11 at 16:28

1

You could try:

FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read, System.IO.FileShare.ReadWrite)

to open the file in a non-exclusive mode.

answered Feb 25 '11 at 16:28

FreeAsInBeer

12,937
5
50
82

score 1 · Answer 3 · answered Feb 25 '11 at 16:29

The type of the exception could help here, but what I can says is this : when a program opens a file it gives two parameters to the OpenFile api :

Desired access : read, write, both ?
Share mode : exclusive, share read, share write, share delete ?

Depending on how the file is open the first time, you may or may not open it a second time : if it's already open with share mode exclusive for example, you won't be able to open it a second time to do something else.

score 0 · Answer 4 · answered Feb 25 '11 at 16:57

After some search I've found a workaround for this problem: Create a FileStream object with the file name, and FileMode.Open, FileAccess.Read, FileShare.ReadWrite as parameters.

Looks like Excel is keeping a write lock on the XLS file while it's running and has the file open, so we need to open the file in ReadWrite fileshare mode.

You can pass in this FileStream object to the Workbook.Load method as parameter, instead of the file name, and the program will then be able to read the file while it's also open in Excel.

FileStream selectedFileStream = new FileStream(currentFileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
Workbook internalWorkBook = Workbook.Load(selectedFileStream);

In the future, it would be helpful if you included all pertinent information in your question. For example, that the file you were trying to open was opened by Excel. — Jim Mischel, Feb 25 '11 at 17:47

How to read a file which is opened in c#?

4 Answers4