eljoseph
asked on
Declaration & " This Process cannot access...." errors in VB.NET
I've a form(developed using WindowsApplication) asking START DATE, END DATE & MESSAGE(which appears on each Windows login in betwen these dates). If Windows login occurs after the END DATE, then 3 days 'll get added. I'm writing all the form values to a separate TXT file called "Dates.txt". For this purpose the code is as & it works properly
Imports System.IO
Public Class Form1
Inherits System.Windows.Forms.Form
Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
If CDateChecker.WriteFile("c:
Me.Close()
Else
MessageBox.Show("Could not write the file")
End If
End Sub
End Class
Public Class CDateChecker
Private Const DATEFORMAT = "dd/MMM/yyyy"
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As String, ByVal dtmEnd As String, ByVal Message As String) As Boolean
Return WriteFile(FileName, Convert.ToDateTime(dtmStar
End Function
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamWriter = Nothing
Try
sw = New StreamWriter(FileName, False)
sw.WriteLine(dtmStart.ToSt
sw.WriteLine(dtmEnd.ToStri
sw.WriteLine(Message)
Return True
Catch ex As Exception
MessageBox.Show("ex.Messag
Return False
Finally
If Not sw Is Nothing Then sw.Close()
End Try
End Function
End Class
The values r now safely written 2 the TXT file. Now I've 2 retrive those. I entered the following code using "ConsoleApplication" & "WindowsApplication" separately. But on runtime, the ConsoleApplication return me the error "Name 'MessageBox' is not declared". Then I tried the same code in WindowsApplication which on run time gave errors like
1st ERROR - "The process cannot access the file 'c:\Dates.txt' because it is being used by another process"
2nd ERROR - "An unhandled error has occurred in your application"
What's the solution for both these errors? So plz tell me what change in code shall b made to remove the above mentioned errors in both application types(i.e. Console & windows appl.)? The code 4 2nd file is as;
CONSOLE APPLICATION CODE
--------------------------
Imports System.IO
Module Module1
Sub Main()
Dim dtmStart As Date
Dim dtmEnd As Date
Dim sMessage As String = String.Empty
If CDateChecker.ReadFile("c:\
If Now >= dtmStart AndAlso Now <= dtmEnd Then
MessageBox.Show(sMessage)
Else
dtmEnd = dtmEnd.AddDays(3)
CDateChecker.WriteFile("c:
End If
End If
End Sub
End Module
Public Class CDateChecker
Private Const DATEFORMAT = "dd/MMM/yyyy"
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As String, ByVal dtmEnd As String, ByVal Message As String) As Boolean
Return WriteFile(FileName, Convert.ToDateTime(dtmStar
End Function
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamWriter = Nothing
Try
sw = New StreamWriter(FileName, False)
sw.WriteLine(dtmStart.ToSt
sw.WriteLine(dtmEnd.ToStri
sw.WriteLine(Message)
Return True
Catch ex As Exception
MessageBox.Show(ex.Message
Return False
Finally
If Not sw Is Nothing Then sw.Close()
End Try
End Function
Public Shared Function ReadFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamReader = Nothing
If Not File.Exists(FileName) Then Return False
Try
sw = New StreamReader(FileName)
dtmStart = Convert.ToDateTime(sw.Read
dtmEnd = Convert.ToDateTime(sw.Read
Message = sw.ReadLine()
Return True
Catch ex As Exception
MessageBox.Show(ex.Message
Finally
If sw Is Nothing Then sw.Close()
End Try
End Function
End Class
--------------------------
WINDOWS APPLICATION CODE
--------------------------
Imports System.IO
Public Class Form1
Inherits System.Windows.Forms.Form
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.Close()
Dim dtmStart As Date
Dim dtmEnd As Date
Dim sMessage As String = String.Empty
If CDateChecker.ReadFile("c:\
If Now >= dtmStart AndAlso Now <= dtmEnd Then
MessageBox.Show(sMessage)
Else
dtmEnd = dtmEnd.AddDays(3)
CDateChecker.WriteFile("c:
End If
End If
End Sub
End Class
Public Class CDateChecker
Private Const DATEFORMAT = "dd/MMM/yyyy"
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As String, ByVal dtmEnd As String, ByVal Message As String) As Boolean
Return WriteFile(FileName, Convert.ToDateTime(dtmStar
End Function
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamWriter = Nothing
Try
sw = New StreamWriter(FileName, False)
sw.WriteLine(dtmStart.ToSt
sw.WriteLine(dtmEnd.ToStri
sw.WriteLine(Message)
Return True
Catch ex As Exception
MessageBox.Show(ex.Message
Return False
Finally
If sw Is Nothing Then sw.Close()
End Try
End Function
Public Shared Function ReadFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamReader = Nothing
Try
sw = New StreamReader(FileName)
dtmStart = Convert.ToDateTime(sw.Read
dtmEnd = Convert.ToDateTime(sw.Read
Message = sw.ReadLine()
Return True
Catch ex As Exception
MessageBox.Show(ex.Message
Return False
Finally
If sw Is Nothing Then sw.Close()
End Try
End Function
End Class
I must tell u about the function of this code. It simply reads the START DATE, END DATE & MESSAGE from the "Dates.txt" file & displays a Msgbox(containing MESSAGE) in between the START & END DATES.
I hope u got understood.... But plz reply me back....
Imports System.IO
Public Class Form1
Inherits System.Windows.Forms.Form
Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
If CDateChecker.WriteFile("c:
Me.Close()
Else
MessageBox.Show("Could not write the file")
End If
End Sub
End Class
Public Class CDateChecker
Private Const DATEFORMAT = "dd/MMM/yyyy"
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As String, ByVal dtmEnd As String, ByVal Message As String) As Boolean
Return WriteFile(FileName, Convert.ToDateTime(dtmStar
End Function
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamWriter = Nothing
Try
sw = New StreamWriter(FileName, False)
sw.WriteLine(dtmStart.ToSt
sw.WriteLine(dtmEnd.ToStri
sw.WriteLine(Message)
Return True
Catch ex As Exception
MessageBox.Show("ex.Messag
Return False
Finally
If Not sw Is Nothing Then sw.Close()
End Try
End Function
End Class
The values r now safely written 2 the TXT file. Now I've 2 retrive those. I entered the following code using "ConsoleApplication" & "WindowsApplication" separately. But on runtime, the ConsoleApplication return me the error "Name 'MessageBox' is not declared". Then I tried the same code in WindowsApplication which on run time gave errors like
1st ERROR - "The process cannot access the file 'c:\Dates.txt' because it is being used by another process"
2nd ERROR - "An unhandled error has occurred in your application"
What's the solution for both these errors? So plz tell me what change in code shall b made to remove the above mentioned errors in both application types(i.e. Console & windows appl.)? The code 4 2nd file is as;
CONSOLE APPLICATION CODE
--------------------------
Imports System.IO
Module Module1
Sub Main()
Dim dtmStart As Date
Dim dtmEnd As Date
Dim sMessage As String = String.Empty
If CDateChecker.ReadFile("c:\
If Now >= dtmStart AndAlso Now <= dtmEnd Then
MessageBox.Show(sMessage)
Else
dtmEnd = dtmEnd.AddDays(3)
CDateChecker.WriteFile("c:
End If
End If
End Sub
End Module
Public Class CDateChecker
Private Const DATEFORMAT = "dd/MMM/yyyy"
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As String, ByVal dtmEnd As String, ByVal Message As String) As Boolean
Return WriteFile(FileName, Convert.ToDateTime(dtmStar
End Function
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamWriter = Nothing
Try
sw = New StreamWriter(FileName, False)
sw.WriteLine(dtmStart.ToSt
sw.WriteLine(dtmEnd.ToStri
sw.WriteLine(Message)
Return True
Catch ex As Exception
MessageBox.Show(ex.Message
Return False
Finally
If Not sw Is Nothing Then sw.Close()
End Try
End Function
Public Shared Function ReadFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamReader = Nothing
If Not File.Exists(FileName) Then Return False
Try
sw = New StreamReader(FileName)
dtmStart = Convert.ToDateTime(sw.Read
dtmEnd = Convert.ToDateTime(sw.Read
Message = sw.ReadLine()
Return True
Catch ex As Exception
MessageBox.Show(ex.Message
Finally
If sw Is Nothing Then sw.Close()
End Try
End Function
End Class
--------------------------
WINDOWS APPLICATION CODE
--------------------------
Imports System.IO
Public Class Form1
Inherits System.Windows.Forms.Form
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.Close()
Dim dtmStart As Date
Dim dtmEnd As Date
Dim sMessage As String = String.Empty
If CDateChecker.ReadFile("c:\
If Now >= dtmStart AndAlso Now <= dtmEnd Then
MessageBox.Show(sMessage)
Else
dtmEnd = dtmEnd.AddDays(3)
CDateChecker.WriteFile("c:
End If
End If
End Sub
End Class
Public Class CDateChecker
Private Const DATEFORMAT = "dd/MMM/yyyy"
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As String, ByVal dtmEnd As String, ByVal Message As String) As Boolean
Return WriteFile(FileName, Convert.ToDateTime(dtmStar
End Function
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamWriter = Nothing
Try
sw = New StreamWriter(FileName, False)
sw.WriteLine(dtmStart.ToSt
sw.WriteLine(dtmEnd.ToStri
sw.WriteLine(Message)
Return True
Catch ex As Exception
MessageBox.Show(ex.Message
Return False
Finally
If sw Is Nothing Then sw.Close()
End Try
End Function
Public Shared Function ReadFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamReader = Nothing
Try
sw = New StreamReader(FileName)
dtmStart = Convert.ToDateTime(sw.Read
dtmEnd = Convert.ToDateTime(sw.Read
Message = sw.ReadLine()
Return True
Catch ex As Exception
MessageBox.Show(ex.Message
Return False
Finally
If sw Is Nothing Then sw.Close()
End Try
End Function
End Class
I must tell u about the function of this code. It simply reads the START DATE, END DATE & MESSAGE from the "Dates.txt" file & displays a Msgbox(containing MESSAGE) in between the START & END DATES.
I hope u got understood.... But plz reply me back....
Carl Tawn
Well the solution to the first is that you need to Import the System.Windows.Forms namepace into your console app in order to use the MessageBox.
ASKER
ok lemme try it then
Thank God somebody replied so far
Thank God somebody replied so far
ASKER
I received the following error on adding this import
"Namespace or type 'Forms' for the Imports 'System.Windows.Forms' cannot be found."
Whats its solution then?
"Namespace or type 'Forms' for the Imports 'System.Windows.Forms' cannot be found."
Whats its solution then?
ASKER CERTIFIED SOLUTION
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ASKER
ok after addinng the DLL file's reference I run the program. It runs but returns with this error
"This process cannot access the "c:\Dates.txt" because it is being used by another process"
Wht 2 do then?
"This process cannot access the "c:\Dates.txt" because it is being used by another process"
Wht 2 do then?
Have you got anything else running that is using the file ?
ASKER
Yeah the portion of the code which writes the form inputs to TXT file. The above mentioned code is included in a separate file 2 retrieve the inputs
You mean you have two apps, both your own that are accessing the file at the same time ?
ASKER
But the first file is not opened in Visual Studio at the moment, only 2nd one
ASKER
Its right that I've developed 2 applications but they dun access at the same time.
The first one simply inputs & the second one runs on every Windows login
The first one simply inputs & the second one runs on every Windows login
Does the logon program release the handle to the file correctly and exit properly when its finished ? If not then it may be retaining a handle to the file.
ASKER
Well look when I tried it till morning 2day, it gives me Msgbox with a particular msg & immediately afterwards the form appears once again to input something
But I dun enter once more & just close it manually
But I dun enter once more & just close it manually
ASKER
Sorry forgot to write u something....... Till morning almost every action was linked to just 1 file, the once placed in the START UP folder.
Just in the afternoon I split the code into 2 separate files & removed the old one from START UP
Just in the afternoon I split the code into 2 separate files & removed the old one from START UP
ASKER
CODE OF FIRST FILE 'FORM1.VB'
--------------------------
Imports System.IO
Public Class Form1
Inherits System.Windows.Forms.Form
Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
If CDateChecker.WriteFile("c:
Me.Close()
Else
MessageBox.Show("Could not write the file")
End If
End Sub
End Class
Public Class CDateChecker
Private Const DATEFORMAT = "dd/MMM/yyyy"
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As String, ByVal dtmEnd As String, ByVal Message As String) As Boolean
Return WriteFile(FileName, Convert.ToDateTime(dtmStar
End Function
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamWriter = Nothing
Try
sw = New StreamWriter(FileName, False)
sw.WriteLine(dtmStart.ToSt
sw.WriteLine(dtmEnd.ToStri
sw.WriteLine(Message)
Return True
Catch ex As Exception
MessageBox.Show("ex.Messag
Return False
Finally
If Not sw Is Nothing Then sw.Close()
End Try
End Function
End Class
CODE OF SECOND FILE MODULE1.VB'
--------------------------
Imports System.IO
Module Module1
Sub Main()
' Create an instance of StreamWriter to write text to a file.
Dim sw As StreamWriter = New StreamWriter("c:\Khan.txt"
' Add some text to the file.
sw.Write("This is the ")
sw.WriteLine("header for the file.")
sw.WriteLine("------------
' Arbitrary objects can also be written to the file.
sw.Write("The date is: ")
sw.WriteLine(DateTime.Now)
sw.Close()
Dim MyMessage As String = ""
MyMessage &= "Computer Name: " & Environment.MachineName & vbCrLf
MyMessage &= "Windows Name: " & Environment.OSVersion.Plat
MyMessage &= "User Name: " & Environment.UserDomainName
MyMessage &= "Computer Started: " & DateTime.Now.AddMillisecon
MsgBox(MyMessage)
End Sub
End Module
--------------------------
Imports System.IO
Public Class Form1
Inherits System.Windows.Forms.Form
Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
If CDateChecker.WriteFile("c:
Me.Close()
Else
MessageBox.Show("Could not write the file")
End If
End Sub
End Class
Public Class CDateChecker
Private Const DATEFORMAT = "dd/MMM/yyyy"
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As String, ByVal dtmEnd As String, ByVal Message As String) As Boolean
Return WriteFile(FileName, Convert.ToDateTime(dtmStar
End Function
Public Shared Function WriteFile(ByVal FileName As String, ByVal dtmStart As Date, ByVal dtmEnd As Date, ByVal Message As String) As Boolean
Dim sw As StreamWriter = Nothing
Try
sw = New StreamWriter(FileName, False)
sw.WriteLine(dtmStart.ToSt
sw.WriteLine(dtmEnd.ToStri
sw.WriteLine(Message)
Return True
Catch ex As Exception
MessageBox.Show("ex.Messag
Return False
Finally
If Not sw Is Nothing Then sw.Close()
End Try
End Function
End Class
CODE OF SECOND FILE MODULE1.VB'
--------------------------
Imports System.IO
Module Module1
Sub Main()
' Create an instance of StreamWriter to write text to a file.
Dim sw As StreamWriter = New StreamWriter("c:\Khan.txt"
' Add some text to the file.
sw.Write("This is the ")
sw.WriteLine("header for the file.")
sw.WriteLine("------------
' Arbitrary objects can also be written to the file.
sw.Write("The date is: ")
sw.WriteLine(DateTime.Now)
sw.Close()
Dim MyMessage As String = ""
MyMessage &= "Computer Name: " & Environment.MachineName & vbCrLf
MyMessage &= "Windows Name: " & Environment.OSVersion.Plat
MyMessage &= "User Name: " & Environment.UserDomainName
MyMessage &= "Computer Started: " & DateTime.Now.AddMillisecon
MsgBox(MyMessage)
End Sub
End Module
ASKER
Ok its running freely now.....
Ok just check the code I posted at first in this question. When I change the system date(greater than the END DATE written in the file), 3 days r not being added. Why?
Is there anyway if the Console DOS Windows doesn't appear on every Windows login? That truly gives a bad impact
Ok just check the code I posted at first in this question. When I change the system date(greater than the END DATE written in the file), 3 days r not being added. Why?
Is there anyway if the Console DOS Windows doesn't appear on every Windows login? That truly gives a bad impact
ASKER
Go to Project -> Add Reference
This is something very new u told me carl_tawn
Thanks
This is something very new u told me carl_tawn
Thanks