Out Of Memory Exception when using StringBuilder

[Patino]

I have a NET CF application running on Mobile 5. The app tries to read
a very BIG file (almost 3 Mb) and store its content in a string. I use
StreamReader to read the file, and stringbuilder to build the string.
However, at some time during this process I get the error:

at System.PInvoke.EE.FastAllocateString()
at System.String.GetStringForStringBuilder()
at System.String.GetStringForStringBuilder()
at System.Text.StringBuilder.GetNewString()
at System.Text.StringBuilder.Append()
at MyProgram.XMLUtils.xmlToString()
: : :

I've been trying to walk through the code when running this one, but
somewhere when the Capacity of my string reaches 117158 the code
freezes.

I need to build that string so that my CF app can upload that string
to a web service application.

Now, the application runs fine (without errors) some times; other
times it crashes with the OutOfMemoryException, on both cases using
the exact same data. The only difference is that: it crashes when the
app has been running for a while in the PDA. It does not crash if a
start a new session of the app and go straight to create that string
to send to the web service.

Any ideas on how I can fix this?

Oh yes, I have added the lines:
GC.Collect();
GC.WaitForPendingFinalizers();
when I instanciate the form that creates this string......and still
the thing crashes.

:-(

 

[Guest]

How about doing the transfer in packets? Trying to do the entire thing in
one shot is a bit insane for the reason you're seeing and others.

 

[Guest]

There are a lot of things that can wrong transferring a 3MB file from a
device. How about you use HttpWebRequest to upload the file asynchronuosly
and when complete have a WebService call pick up the file and work with it.

Passing a 3MB file via a WebService call is going to kill any interface
responsivness, and is way too dependent on a good connection.

 

[Patino]

Thanks for your reply. We are going to break the file into smaller
chunks as you suggest. We also realized that running our app with such
a big input file was taking more than 20MB of memory to run. The
typical input file for our app with files of < 200Kb uses 2 or 3 MB of
memory to run, a big difference in performance. It is just that once
in a while some user decides to uplaod these big input files.

 

[Patino]

Thanks for your reply. We are going to break the file into smaller
chunks as you suggest. We also realized that running our app with such
a big input file was taking more than 20MB of memory to run. The
typical input file for our app with files of < 200Kb uses 2 or 3 MB of
memory to run, a big difference in performance. It is just that once
in a while some user decides to uplaod these big input files.