Ok, in my proyect iam trying to simulate a drawing editor, but i want to create a Log File ( drawing.txt )
in this file i want that every line have two points example:
{100,100},{200,00} // this for the first line drawn
{45,88},{82,89} // this for the second line ...
//... etc, for every line drawn
so i did in my code a function, fucntion that is called by the event OnPaint
public
void logactions(Point a, Point b){
string path_string = "C:\\Drawing1.txt";
using (StreamWriter _path = new StreamWriter(path_string))
{
string data = a.ToString() + "," + b.ToString();
_path.WriteLine(data);
_path.Close();
}
}
this code create succesfully the first line, but this line is overwriten by the next line, and this for the next ... etc...
how can i create this kind of custom log , please help me 
Writing a txt File problem
Confused4130
1/ OnPaint is called constantly, this is the wrong place to be writing to a log file, you have no control over it
2/ You're creating a new file every time, that's why it's overriting. There's a File.Open shortcut in 2.0, but any option for opening a file has an overload where you can specify if you want to create a new file or append an old one
3/ For something like this, I'd open the file as a member variable, rather than have the cost of opening and closing it constantly
Jason Fransella
Yep, sounds good, except you can use File.Open ( from memory ) and append the file instead of worrying about overwriting it.
pate
{
_file.Close();
}
No, in both cases, you're not storing the file as a member variable. In one, you create a temp variable, in the other you open the file and don't store the return value at all. You want to open it to a *member* variable in both cases, then you write to it where-ever you like, and make sure it's closed in your Dispose/Finalise methods.
Ernie Thomason
DS1
Finally, if Im wrong, please let me know... if Im ok, so i hope this post should help you ...
// Adding in the form class
FileStream _file;
// OnLoad
private void FlatPlane_Load(object sender, EventArgs e)
{
if (!File.Exists(path))
{
// Create the file.
using (_file = File.Open(path, FileMode.Append))
{
}
}
}
//MouseUp
private void FlatPlane_MouseUp(object sender, MouseEventArgs e)
{
//si fue del izq
if (e.Button == MouseButtons.Left)
{
b.X = e.X;
b.Y = e.Y;
this.LogIt(a, b);
this.Invalidate();
}
Pinta = false;
}
// Log the activity
public void LogIt(Point a, Point b)
{
_file = File.Open(path, FileMode.Append);
Byte[] info = new UTF8Encoding(true).GetBytes(a.ToString() + "," + b.ToString() + "\n");
// Add some information to the file.
_file.Write(info, 0, info.Length);
_file.Dispose();
}
John Roper-Lindsay
Sorry, the output or the drawing1.txt file have the following...
{234,585},{456,785} // this is the las Line drawn in the form so where are the previous lines
likestoski
Cool, so now the Code in the OnLoad E/M looks like this...
// OnLoad
private void FlatPlane_Load(object sender, EventArgs e)
{
if (!File.Exists(path))
{
// Create the file.
using (FileStream _file = File.Open(path,FileMode.Create))
{
_file.Close();
}
}
else
{
File.Open(path, FileMode.Append);
}
}
but im still don't know how to write it, but I will figure it out, thank you so much...
Benjamin Ray
Ok, thx, then I must create the file outside the OnPaint Event/Method, and I will place it inside the OnLoad Event/Method... that's cool, so now the "Log Activity" I will place it inside the OnMouseUp Event/Method so in this case I have the control and I will log the activity when i place the last point ... I'm Ok
But now i have a new question:
If I use in the OnLoad E/M
if (!File.Exists(path))
{
// Create the file.
using (FileStream _file = File.Create(path))
{
// Add some cool stuff
}
}
now how can I write the txt file in the OnMouseUp E/M
misfit815
Your onload call is a total waste of time. What you've done will work, but it still opens the file every time you want to write to it.
_file = File.Open(path, FileMode.Append);
This should be in your Load event, and the Dispose call should be replaced by Close, and THEN Dispose, and then set the variable to NULL, and this should take place in the Close event of the form, assuming this is in a form.