CODEWITHSUNDEEP
c#winforms
Wladyslaw Koshyl
Wladyslaw Koshyl

Reputation: 13

Method throws error because file is accessed by another process

This function doesn't work because another process is using it.

The function must read the file, do something with it's data and write the result to this file.

private void changeToolStripMenuItem_Click(object sender, EventArgs e)
    {
        LB2.Visible = true;
        TB2.Visible = true;
            SaveFileDialog save = new SaveFileDialog();
            if (save.ShowDialog() == DialogResult.OK)
            {
                double maxlen;
                BinaryReader read = new BinaryReader(new FileStream(save.FileName, FileMode.Open));
                BinaryWriter w = new BinaryWriter(new FileStream(save.FileName, FileMode.Create));
                Find(read, out maxlen);
                while (read.BaseStream.Position < read.BaseStream.Length)
                {
                    double A = read.ReadDouble();
                    if (A > 0)
                    {
                        read.BaseStream.Seek(-8, SeekOrigin.Current);
                        w.Write(Find(read, out maxlen));
                    }
                    else
                        w.Write(A);

                }
                read.BaseStream.Close();
                w.BaseStream.Close();
            }
        }

Upvotes: 1

Views: 616

Answers (5)

Ken Kin
Ken Kin

Reputation: 4683

Change it to: 

var fs=new FileStream(save.FileName, FileMode.OpenOrCreate);
BinaryReader read=new BinaryReader(fs);
BinaryWriter w=new BinaryWriter(fs);

and remove:

w.BaseStream.Close();

Upvotes: 0

Justin
Justin

Reputation: 4072

I would do this to make sure your streams are getting closed

using( BinaryReader read = new BinaryReader(new FileStream(save.FileName, FileMode.Open)))
{
   using( BinaryWriter w = new BinaryWriter(new FileStream(save.FileName, FileMode.Create)) )
   {
       // CODE HERE
   }
}

It sounds like you're getting an exception and you're not closing your streams/readers/writers.

Upvotes: 2

tnw
tnw

Reputation: 13877

BinaryReader read = new BinaryReader(new FileStream(save.FileName, FileMode.Open));
BinaryWriter w = new BinaryWriter(new FileStream(save.FileName, FileMode.Create));

Same file. BinaryWriter probably encounters the exception, though I'm not entirely sure because you haven't showed us. You need to close your BinaryReader before you can do anything else with that file.

Upvotes: 2

Keith Nicholas
Keith Nicholas

Reputation: 44288

you seem to be opening the same file twice?

 BinaryReader read = new BinaryReader(new FileStream(save.FileName, FileMode.Open));
 BinaryWriter w = new BinaryWriter(new FileStream(save.FileName, FileMode.Create));

Upvotes: 2

Sam I am says Reinstate Monica
Sam I am says Reinstate Monica

Reputation: 31184

my psychic debugging sense says that it's the FILE that's in use

And you're getting the error because you didn't close your BinaryReader before you created your BinaryWriter

instead of this

BinaryReader read = new BinaryReader(new FileStream(save.FileName, FileMode.Open));
BinaryWriter w = new BinaryWriter(new FileStream(save.FileName, FileMode.Create));

...

read.BaseStream.Close();
w.BaseStream.Close();

do this

BinaryReader read = new BinaryReader(new FileStream(save.FileName, FileMode.Open));
...
read.BaseStream.Close();

BinaryWriter w = new BinaryWriter(new FileStream(save.FileName, FileMode.Create));
...
w.BaseStream.Close();

Upvotes: 2

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