StreamWriter IO Exception - file used by another process

Question

I have a big problem with my code i allways get a IO Exception and i don´t know why... I use a StreamWriter...

    internal void SaveOwner(Owner o)
    {
        StreamWriter w = new StreamWriter(path, true);
        if (o != null)
            w.WriteLine(o.ToFileString());
        w.Close();
    }

Pleace can anyone help me i don´t konw i have tried everything what i konw..!? It allways says that a other process use the file. IO Exception - file used by another process Befor i call the Method i asked if o != null

the code is in C#

Answer 1

I believe this is caused because of multi-threading due to that I was able to reproduce your issue by that.

Thrown Exception

You can simply wrap a lock (Use a static object.) and for goodness sake use the using keyword to wrap your stream.

static object syncRoot = "";

...

void SaveOwner(Owner o)
{
    lock (syncRoot)
    {
        using (StreamWriter w = new StreamWriter(path, true))
        {
            if (o != null)
                w.WriteLine(o.ToFileString());
        }
    }
}