How to close parent form and open child? - vb.net

Question

Hey guys before I was just hiding the parent form, but now when I try to read from the parent file it says it can't because it's already running in a process. I followed some tutorial and it said to go to the project properties and have the application stop running when all the forms are closed.
But now since I did that it says the directory can't be found probably because I am reading the input from the parent form. Anyways here is my code
Dim writeFile1 As StreamWriter = New StreamWriter(File.OpenWrite("C:\Users\Nick\Documents\Visual Studio 2010\Projects\LoginFixed\Accounts\" + frmLogin.txtUser.Text))
How should I go about doing this?
Edit:
Private Sub btnHunter_Click(sender As System.Object, e As System.EventArgs) Handles btnHunter.Click
selection = "Hunter"
writeData.classSelection()
End Sub
This is what I have when the button is clicked.
Here is the classSelection sub:
Public Sub classSelection()
If frmClass.selection = "Hunter" Then
writeFile1.WriteLine(frmClass.selection)
End If
If frmClass.selection = "Gatherer" Then
writeFile1.WriteLine(frmClass.selection)
End If
If frmClass.selection = "Farmer" Then
writeFile1.WriteLine(frmClass.selection)
End If
writeFile1.Close()
End Sub
The error points to this line:
If frmClass.selection = "Hunter" Then
Saying part of the file path cannot be found.

Answer 1

If you want to read input textbox in closed parent form, you have to declare public var
Make a new module in your project .. and add this
public sLogin as String
And before you hide or close frmLogin .. add this
sLogin = txtUser.Text
So, you could change your code with
Dim writeFile1 As StreamWriter = New StreamWriter(File.OpenWrite("C:\Users\Nick\Documents\Visual Studio 2010\Projects\LoginFixed\Accounts\" & sLogin))

Answer 2

matzone has given you a good hint. And to check exactly what your path is, just add a MessageBox using variables :
Dim writePath1 As String
Dim writeFile1 As StreamWriter
writePath1 = "C:\Users\Nick\Documents\Visual Studio 2010\Projects\LoginFixed\Accounts\" & sLogin
If MessageBox.Show(writePath1, "Continue ?", MessageBoxButtons.YesNo) = DialogResult.Yes Then
writeFile1 = New StreamWriter(File.OpenWrite(writePath1))
' ...
writeFile1.Close() ' Very important ! Adrian pointed it out.
End If
^^ and if it works, you can discard the Dialog test or replace it by some test code like If File.Exists(...)
However, I don't understand wether you want to close the parent Form or hide it. It's different !
Closing the parent Form will discard any access to parent Form members, including txtUser.Text.
If you want to close the parent Form, the ChildForm should not be a child of that parent you are trying to close, or you must just hide the parent Form :
frmLogin.Hide() ' Not frmLogin.Close()
If you close frmLogin, frmLogin.txtUser won't be accessible, or use sLogin provided by matzone instead. Alternatively, you should pass frmLogin.txtUser.Text value to a custom property of ChildForm.
Imports System.IO
Public Partial Class ChildForm1
' Inherits System.Windows.Form
' ...
Private _txtUserFile As String
Public WriteOnly Property TxtUserFile() As String
Set(ByVal NewFileName As String)
_txtUserFile = NewFileName
End Set
End Property
Public Sub LoadFile()
Dim writeFile1 As StreamWriter = New StreamWriter(File.OpenWrite("C:\Users\Nick\Documents\Visual Studio 2010\Projects\LoginFixed\Accounts\" & txtUserFile))
' ...
writeFile1.Close()
End sub
' ...
End Class
Then use this in parent Form :
MyChildForm.TxtUserFile = Me.txtUser.Text
' Me.Close() ' This will definately KILL Form1 (the parent one)
Me.Hide() ' Always use Hide() until you'll terminate your Application
MyChildForm.Show()
MyChildForm.LoadFile()
^^ but this is not a good code either ! Your problem remains unclear (at least for me)
"Still saying it can't find part of the path", then check the path..
Does the file actually exists ?
Does the path contains glitch ? (use the provided MessageBox test)
Does your account can access that directory ? (Windows configuration and account levels)

Answer 3

Well !
In fact, the problem could be somewhere else.
For example, I was able to reproduce your exception by providing an empty string [""] as the value of, either :
frmLogin.txtUser.Text ' = ""
' or
sLogin ' = ""
' or
txtUserFile ' = ""
In fact, I get the "Could not find a part of the path..." exception because the StreamWriter couldn'd read/write to a File, as I didn't provided a valid FileName for that file. As the filename parameter was an empty string "", the provided path for StreamWriter was just representing a directory instead of a file and an exception was raised.
Now, you should check wether you have a valid path before building a new instance of StreamWriter to get sure you are actually pointing to a File ?
Dim writeFile1 As StreamWriter
Dim MyEntirePath As String = "C:\Users\...\Accounts\" + frmLogin.txtUser.Text
MessageBox.Show(MyEntirePath) ' would be enough to be sure your path is correct
' Some test code here...
If everythingOK then ' create the StreamWriter...
writeFile1 = New StreamWriter(MyEntirePath)
' ...
' ...
Also, it's not a good idea to create your streamwriter, and use it in another part/method of your code. You never known if one day, you'll change your code, and forget to make the link between
Dim writeFile1 As StreamWriter = New StreamWriter(File.OpenWrite("C:\Users\Nick\Documents\Visual Studio 2010\Projects\LoginFixed\Accounts\" + frmLogin.txtUser.Text))
' plus
Private Sub btnHunter_Click(sender As System.Object, e As System.EventArgs)
...
End Sub
' plus
Public Sub classSelection()
...
writeFile1.Close()
End Sub
^^ too much "here and there"...
You'll obviously also get an exception if you try to click btnHunter twice.. I don't know what is the purpose of your code nor how it works, it looks like a game.. But I would use File.Exist(..) checks, create the file before, if none, and put that in a Try/Catch to check if I eventually don't have administrator rights to write to that directory. Otherwise, make a code that allow user to read/write files to a custom folder. Andalso, you have :
Application.StartupPath
^^ Very usefull, like :
Dim MyFilePath As String = Application.StartupPath + "\Datas\MyText.txt"
After two weeks of coding, I usually forget where I put those "C:\blabla.." or "D:\gnagna\" or what classes actually uses those absolute reference paths. I've dropped this way of getting directories long ago since the day I moved to Win7 on another computer and all such applications I developped using that approach was doomed...