New to .NET and file IO

[simon77]

OK, I'm trying to read a file in, three columns of numbers in all, each column into a seperate array.

 

Last week I would have done something like:

char filename[25];

std::ifstream afile(filename); //

and then just loop till the end of the file using the >> operator.

 

But now we've got .NET installed and having my first a attempt at forms and dialouge boxes rather than my usual console stuff. Anyway I'm using streamreader to read the file in but can't grab less than a line at a time.

 

StreamReader* objReader = new StreamReader

String *sLine = "";

sLine = objReader->ReadLine();

 

Surely I don't have to search through the string for a empty space and then split the string into smaller ones and then convert to a double. There must be a better way. Please enlighten me. Cheers

 

Apologies for being dim. I promise I've googled long and hard for the answer...

[PlausiblyDamp]

It may help if you give a little more detail about how the file is structured and what kind of variables etc. you are attempting to read into.

If you wish to read less than a line the StreamReader has a .Read method that gives you a bit more control over the reading process, or as an alternative you could do a .ReadToEnd and then use something like regular expressions to parse the resulting string.

[simon77]

basically, its a series of x y z coordinates that I want in three arrays: double x[], double y[] and double z[]. So only three numbers to a line but could be any size numbers and any number of lines. I'll go check out the .Read method. Thanks.

[Napivo1972]

Surely I don't have to search through the string for a empty space and then split the string into smaller ones and then convert to a double. There must be a better way. Please enlighten me. Cheers

 

That is exactly what you need to do but vb.net makes it easy

 

Try this

 

Public Sub ReadFile(ByVal Filename As String)
       Dim tStr As String
       Dim Coord(3) As Single
       Dim SR As TextReader = New StreamReader(Filename) 'Open File
       Do
           tStr = SR.ReadLine �read a ine
           If Not IsNothing(tStr) Then Coord = Coordsplitter(tStr)
       Loop Until IsNothing(tStr)
   End Sub

   Private Function Coordsplitter(ByVal tstr As String) As Single()
�Splits the String
       Dim vCoord(3) As Single
       Dim t1 As Integer = 0
       For Each value As String In Split(tstr, " ", 3) �Split in 3 pieces
           vCoord(t1) = Convert.ToSingle(value) �Convert to Single
           t1 = t1 + 1
       Next
       Return vCoord
   End Function

 

this is the text file I assumed

 

12.23 13.12 123.32
12.23 13.12 123.33
12.23 13.12 123.34
12.23 13.12 123.35
12.23 13.12 123.36

 

Hope it helps

[simon77]

Ahh brilliant. Thanks a lots, thats what I was after.