Creating and saving files in C#

Question

I need to create and write to a .dat file. I'm guessing that this is pretty much the same process as writing to a .txt file, but just using a different extension.

In plain english I would like to know how to:

-Create a .dat file

-Write to it

-And save the file using SaveFileDialog

There are a few pages that I've been looking at, but I think that my best explanation will come from this site because it allows me to state exactly what I need to learn.

The following code is what I have at the moment. Basically it opens a SaveFileDialog window with a blank File: section. Mapping to a folder and pressing save does not save anything because there is no file being used. Please help me use this to save files to different locations.

Microsoft.Win32.SaveFileDialog dlg = new Microsoft.Win32.SaveFileDialog();
dlg.FileName = "";
dlg.DefaultExt = "";

Nullable<bool> result = dlg.ShowDialog();

if (result == true)
{
    string filename = dlg.FileName;
}

Pages that I've been looking at:

-http://msdn.microsoft.com/en-us/library/8bh11f1k.aspx

-http://social.msdn.microsoft.com/Forums/en-US/cd0b129f-adf1-4c4f-9096-f0662772c821/how-to-use-savefiledialog-for-save-text-file

-http://msdn.microsoft.com/en-us/library/system.io.file.createtext(v=vs.110).aspx

Answer 1

Note that the SaveFileDialog only yields a filename but does not actually save anything.

var sfd = new SaveFileDialog {
    Filter = "Text Files (*.txt)|*.txt|All files (*.*)|*.*",
    // Set other options depending on your needs ...
};
if (sfd.ShowDialog() == true) { // Returns a bool?, therefore the == to convert it into bool.
    string filename = sfd.FileName;
    // Save the file ...
}

Use the filename you are getting from the SaveFileDialog and do the following:

File.WriteAllText(filename, contents);

That's all if you intend to write text to the file.

You can also use:

File.WriteAllLines(filename, contentsAsStringArray);

Answer 2

using(StreamWriter writer = new StreamWriter(filename , true))
{
  writer.WriteLine("whatever your text is");
}