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How to retrieve data from a .txt file

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Re: How to retrieve data from a .txt file

#11

Jun 2nd, 2009

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Originally Posted by Teme64

' Read the whole file to a string
FileText = My.Computer.FileSystem.ReadAllText("D:\account.txt")

I just have one comment.

The above line will read the whole file at once. if the file is big it may lead to memory problem, I prefer to read line by line, I guess my code will be faster on PII with 64mb ram.

Samir Ibrahim
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Re: How to retrieve data from a .txt file

#12

Jun 2nd, 2009

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The above line will read the whole file at once. if the file is big it may lead to memory problem, I prefer to read line by line, I guess my code will be faster on PII with 64mb ram.

If you deal with small files (a few tens or hundreds of KBs) or you need to keep the whole file in the memory anyway, using My namespace is very handy requiring only a few lines of code. Besides, My namespace does have quite a few other handy classes too, not just My.Computer.FileSystem. If you don't need to keep the whole file in the memory or the file is really large, System.IO is absolutely the better solution. What comes to the speed of the code, with modern processor there's hardly any practically significant difference.

And after all, it's a question about selecting the right "tool"

Teme64 @ Windows Developer Blog

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Sylenas

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Re: How to retrieve data from a .txt file

#13

Jun 4th, 2009

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Originally Posted by Teme64

To get those values to text boxes goes like this
Help with Code Tags

VB.NET Syntax (Toggle Plain Text)
TextBox1.Text = OneLine(0)
TextBox2.Text = OneLine(1)
TextBox1.Text = OneLine(0) TextBox2.Text = OneLine(1)
Now TextBox1 should show "Account" and TextBox2 should show " Apple".

That explanation totally cleared things up for me, thankyou so much! now my text box is showing text from the file but its showing the whole last line. This is what i have:

 Help with Code Tags 
 VB.NET Syntax (Toggle Plain Text) 
    Private Sub Fill()
 
 
        If My.Computer.FileSystem.FileExists("C:\Travian.txt") Then
 
            FileText = My.Computer.FileSystem.ReadAllText("C:\Travian.txt")
 
            FileLines = FileText.Split(CChar(Environment.NewLine))
            SeparatorChar = ","
 
            For i = 0 To FileLines.GetUpperBound(0)
                OneLine = FileLines(i).Split(CChar(SeparatorChar))
 
            Next i
        End If
 
        txtUser.Text = OneLine(0)
    End Sub
    Private Sub Fill()
       
        
        If My.Computer.FileSystem.FileExists("C:\Travian.txt") Then

            FileText = My.Computer.FileSystem.ReadAllText("C:\Travian.txt")

            FileLines = FileText.Split(CChar(Environment.NewLine))
            SeparatorChar = ","

            For i = 0 To FileLines.GetUpperBound(0)
                OneLine = FileLines(i).Split(CChar(SeparatorChar))

            Next i
        End If

        txtUser.Text = OneLine(0)
    End Sub

After the button is clicked text shows up in txtUser but its the whole last line of my text document. Have i done something wrong here or have i given the wrong index for OneLine?

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Teme64

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Re: How to retrieve data from a .txt file

#14

Jun 4th, 2009

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but its showing the whole last line.

Your last line does not have that separator character. That's why the whole line ends up to OneLine(0).

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have i given the wrong index for OneLine?

It depends on your data, what the index should be. Start with zero and see what you get. Then try OneLine(1). You'll get an "Index out of bounds" error finally.

Can you tell me, for what purpose this

 Help with Code Tags 
 VB.NET Syntax (Toggle Plain Text) 
For i = 0 To FileLines.GetUpperBound(0)
   OneLine = FileLines(i).Split(CChar(SeparatorChar))
Next i
For i = 0 To FileLines.GetUpperBound(0)
   OneLine = FileLines(i).Split(CChar(SeparatorChar))
Next i

loop is? Do you need that loop? You have a single txtUser.Text text box (showing in your code). If you know that your data should come, for example, from the first line in the file, use simply

 Help with Code Tags 
 VB.NET Syntax (Toggle Plain Text) 
OneLine = FileLines(0).Split(CChar(SeparatorChar))
txtUser.Text = OneLine(0)
OneLine = FileLines(0).Split(CChar(SeparatorChar))
txtUser.Text = OneLine(0)

without a loop.

Or post the data you're using and explain how you should display it in the form.

Teme64 @ Windows Developer Blog

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Re: How to retrieve data from a .txt file

#15

Jun 4th, 2009

Ok so my form looks like this

Account: _______
Username: ______
Password: ______
The account, username and password are labels and the ____ represent textboxes named appropriately. When i save the data it gets put into a text document that is named like this: txtAccount.Text & ".txt"
and the data in the text file is like this:

Account: Apple
Username: Orange
Password: Banana

basically what happens now is that it is only looking for one file (but ill fix it to look for the user specified file later) and then like you said it reads the file, splits it into lines then splits each line into two parts. I want the bit after the seperator to appear in the text box basically and so far its just putting the last line of the text file in. I also changed the value of OneLine to (1) but then it said the array was out of bounds so im thinking its actually starting to read from the last line of the text file.

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Teme64

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Re: How to retrieve data from a .txt file

#16

Jun 4th, 2009

Ok, you have three lines which you need to show (didn't remember your first post). Your code should be something like this

 Help with Code Tags 
 VB.NET Syntax (Toggle Plain Text) 
' Assuming you have multiple "triple" entries in your file
For i = 0 To FileLines.GetUpperBound(0) Step 3
  OneLine = FileLines(i).Split(CChar(SeparatorChar))
  txtAccount.Text = OneLine(1).Trim
  OneLine = FileLines(i + 1).Split(CChar(SeparatorChar))
  txtUserName.Text = OneLine(1).Trim
  OneLine = FileLines(i + 2).Split(CChar(SeparatorChar))
  txtPassword.Text = OneLine(1).Trim
Next i
 
' Or with a single entry in the file (no loop needed)
OneLine = FileLines(0).Split(CChar(SeparatorChar))
txtAccount.Text = OneLine(1).Trim
OneLine = FileLines(1).Split(CChar(SeparatorChar))
txtUserName.Text = OneLine(1).Trim
OneLine = FileLines(2).Split(CChar(SeparatorChar))
txtPassword.Text = OneLine(1).Trim
' Assuming you have multiple "triple" entries in your file
For i = 0 To FileLines.GetUpperBound(0) Step 3
  OneLine = FileLines(i).Split(CChar(SeparatorChar))
  txtAccount.Text = OneLine(1).Trim
  OneLine = FileLines(i + 1).Split(CChar(SeparatorChar))
  txtUserName.Text = OneLine(1).Trim
  OneLine = FileLines(i + 2).Split(CChar(SeparatorChar))
  txtPassword.Text = OneLine(1).Trim
Next i

' Or with a single entry in the file (no loop needed)
OneLine = FileLines(0).Split(CChar(SeparatorChar))
txtAccount.Text = OneLine(1).Trim
OneLine = FileLines(1).Split(CChar(SeparatorChar))
txtUserName.Text = OneLine(1).Trim
OneLine = FileLines(2).Split(CChar(SeparatorChar))
txtPassword.Text = OneLine(1).Trim

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I also changed the value of OneLine to (1) but then it said the array was out of bounds

Check that SeparatorChar variable has the correct value (it should be ":" I think, now your code is using ",").

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im thinking its actually starting to read from the last line of the text file.

It starts from the first line. Like I commented in the code above, it all depends if you have a single

Account: Apple
Username: Orange
Password: Banana

or multiple Account, Username and Password lines. In that case, the code will loop and use the last "triple".

Last edited by Teme64; Jun 4th, 2009 at 6:01 am. Reason: Pressed Submit button by mistake

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Re: How to retrieve data from a .txt file

#17

Jun 4th, 2009

YES!! IT WORKED! Oh thats fantastic i'm so happy. now i gotta figure out how to get the thing to look for files =P
Thankyou so much for the help and putting up with my crap!!!

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Re: How to retrieve data from a .txt file

#18

Jun 4th, 2009

Hi! Nice to hear that you got answer to your problem. Could you please mark the thread as solved. Thank you!

If you run in to a problem you can't solve, when looking for the files, start a new thread for that, please.

P.s. take a look at OpenFileDialog control...

Teme64 @ Windows Developer Blog