CODEWITHSUNDEEP
c#
user1447343
user1447343

Reputation: 1457

StreamWriter has a Bug?

this simply writes the text in textbox to the same file each time...I don't understand why it works perfectly if I input new characters or change characters while deleting characters doesn't work...

 private void ContentChanged(object sender, TextChangedEventArgs e)
        {
            Console.WriteLine("cur before:" + this.Box.SelectionStart);
            FileStream f = File.Open(path, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
            StreamWriter writer = new StreamWriter(f);
            model.Cursor = this.Box.SelectionStart;
            writer.Write(this.Box.Text);
            writer.Close();
            Console.WriteLine("cur after:" + this.Box.SelectionStart);
            Console.WriteLine("write:" + count++);
            Console.WriteLine("after write:" + this.Box.Text);
            Console.WriteLine("after write:" + model.Content);
        }

Upvotes: 0

Views: 447

Answers (3)

user1447343
user1447343

Reputation: 1457

I found out why.

The StreamWriter constructor I used couldn't set the attribute "append" to false, so each time I'm overriding the existing text, not starting from scratch.

Since I have to use FileStream for multi-thread reason, I guess I would have to find another way of writing the file.

Upvotes: 0

Yusubov
Yusubov

Reputation: 5843

In short: you need to re-write your code like in the following sample by using keyword. As it prevents the leaks and is recommended way to deal with un-managed resources in .NET Framework.

using(StreamWriter writer = new StreamWriter(Response.OutputStream))
{
    writer.WriteLine("col1,col2,col3");
    writer.WriteLine("1,2,3");
    writer.Close(); //not necessary I think... end of using block should close writer
}

Edit: In your code sample you are opening the FileStream but do not close it, which causes the issues. Thus, preventing that with a convenient using statement is proffered way to go. Otherwise, you just need to close your filstream or any un-managed resources.

Upvotes: 0

Jon Skeet
Jon Skeet

Reputation: 1500065

You're not closing f or flushing - it's entirely possible that the data is being buffered, which is why it never makes it to the file.

Two suggestions:

  • Use using statements with disposable resources such as streams and writers
  • Use File.CreateText to create a TextWriter in one call - or better yet, use File.WriteAllText to avoid having to worry about opening and closing at all.

So something like this:

private void ContentChanged(object sender, TextChangedEventArgs e)
{
    Console.WriteLine("cur before:" + this.Box.SelectionStart);
    File.WriteAllText(path, this.Box.Text);
    Console.WriteLine("cur after:" + this.Box.SelectionStart);
    Console.WriteLine("write:" + count++);
    Console.WriteLine("after write:" + this.Box.Text);
    Console.WriteLine("after write:" + model.Content);
}

Upvotes: 4

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