I am creating a form that will prompt the user to enter a file name upon loading the file. The issue I encounter is that my variable I use to store the input is not recognized in another one of my procedures. The code here shows my current set up.
Imports System.IO
Public Class frmEmployee
Sub frmEmployee_load(ByVal sender As Object, e As System.EventArgs)
Dim strFileName = InputBox("Please name the file you would like to save the data to: ")
End Sub
Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click
txtEmail.Clear()
txtExtension.Clear()
txtFirst.Clear()
txtLast.Clear()
txtMiddle.Clear()
txtNumber.Clear()
txtPhone.Clear()
End Sub
Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
Dim inputFile As New StreamWriter(strFileName)
If File.Exists(strFileName) = True Then
inputFile = File.CreateText(strFileName)
inputFile.Write(txtEmail.Text)
inputFile.Write(txtExtension.Text)
inputFile.Write(txtFirst.Text)
inputFile.Write(txtLast.Text)
inputFile.Write(txtMiddle.Text)
inputFile.Write(txtNumber.Text)
inputFile.Write(txtPhone.Text)
inputFile.Write(cmbDepart.Text)
Else
MessageBox.Show("" & strFileName & "Cannot be created or found.")
End If
End Sub
Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
Me.Close()
End Sub
End Class
The load event handler is where I want the user to input the name of the file.
Change the scope of your variable to outside of your load method...
Public Class frmEmployee
Private strFileName As String
Sub frmEmployee_load(ByVal sender As Object, e As System.EventArgs)
strFileName = InputBox("Please name the file you would like to save the data to: ")
End Sub
You could use My.Settings and load the file string there and save it. All forms can now access that. When you close the the app set it to String.Empty if you want it to be.
You also could be taking advantage of a class object for the fields you are capturing then using either BinaryFormatter or XmlSerializer to store the data. Better databinding, creation and reconstruction using an object.
My.Settings.Filename = Inputbox("Filename?")
My.Settings.Save()
The problem with the approach you have there is that your variabl strFileName is scoped to the class frmEmployee.
You need to set up a genuinely global variable (at the application startup) an then use that. So you will need a Sub Main as an entry point to your application See here, and just before that create a public variable to hole the file name.
So you might have something like this for your application startup:
Public fileNametoUse as string
Public Sub Main()
Application.EnableVisualStyles()
Application.SetCompatibleTextRenderingDefault(False)
Application.Run(New Form1)
End Sub
Then in you load sub for frmEmployee you would have:
fileNametoUse = InputBox("Please name the file you would like to save the data to: ")
Related
I'm new to this site and also a newbee in vb.net, I created a simple form in vb.net, a form with 3 buttons, by clicking Button1 Species1.txt is created, and by clicking Button2 the lines in Species1.txt are copied in a String Array called astSpecies(), and by Button3 the String Array is copied in a new file, named Species2.txt, below is the code.
Public Class Form4
Dim astSpecies() As String
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myStreamWriter = New StreamWriter("C:\Users\Administrator\Documents\species1.txt", True)
myStreamWriter.WriteLine("Pagasius pangasius")
myStreamWriter.WriteLine("Meretrix lyrata")
myStreamWriter.WriteLine("Psetta maxima")
myStreamWriter.WriteLine("Nephrops norvegicus")
myStreamWriter.WriteLine("Homarus americanus")
myStreamWriter.WriteLine("Procambarus clarkii")
myStreamWriter.Close()
MsgBox("list complete")
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim myStreamReader = New StreamReader("C:\Users\Administrator\Documents\species1.txt")
Dim i As Integer
Dim stOutput As String
stOutput = ""
Do While Not myStreamReader.EndOfStream
astSpecies(i) = myStreamReader.ReadLine
stOutput = stOutput & astSpecies(i) & vbNewLine
i = i + 1
Loop
myStreamReader.Close()
MsgBox(stOutput)
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Dim myStreamWriter = New StreamWriter("C:\Users\Administrator\Documents\species2.txt", True)
Dim o As Integer
Do While o <= astSpecies.Length
myStreamWriter.WriteLine(astSpecies(o))
o = o + 1
Loop
myStreamWriter.Close()
End Sub
End Class
First of all, you should make a few settings when it comes to VB.Net. 1.) set Option Strict to On 2.) remove the VB6 namespace. VB6 is the old Visual Basic. There are many functions in this that are inefficient from today's perspective. So please do not write MsgBox() but MessageBox.Show("").
(If you still need control characters such as NewLine or Tab, you can set a selective reference with Imports Microsoft.VisualBasic.ControlChars. Sounds contradictory, but it is useful, because why should you also write ChrW(9), it is not legible.)
I quickly started a project myself and wrote whatever you wanted.
I still don't quite understand why you first write things into a text file, then read them out, and then write that into a second text file – I want to say: where do the strings originally come from? The strings must have been there already? Anyway, I filled a List(of String) in the Button2_Click procedure. This has the advantage that you don't have to know in advance how many strings are coming, and you can sort them later and so on ...
You should also discard all Writers when you no longer need them. So use Using. Otherwise it can happen that the written files are not discarded and you can no longer edit the file.
Imports Microsoft.VisualBasic.ControlChars
Imports Microsoft.WindowsAPICodePack.Dialogs
Public NotInheritable Class FormMain
Private Path As String = ""
Private allLines As New List(Of String)
Private Sub FormMain_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Me.BackColor = Color.FromArgb(161, 181, 165)
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Using OFolderD As New CommonOpenFileDialog
OFolderD.Title = "Ordner auswählen"
OFolderD.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
OFolderD.IsFolderPicker = True
If OFolderD.ShowDialog() = CommonFileDialogResult.Ok Then
Path = OFolderD.FileName
Else
Return
End If
End Using
Path &= "\Data.txt"
Using txtfile As System.IO.StreamWriter = My.Computer.FileSystem.OpenTextFileWriter(Path, True)
txtfile.WriteLine("Pagasius pangasius")
txtfile.WriteLine("Meretrix lyrata")
txtfile.WriteLine("Psetta maxima")
txtfile.WriteLine("Nephrops norvegicus")
txtfile.WriteLine("Homarus americanus")
txtfile.WriteLine("Procambarus clarkii")
txtfile.Close()
End Using
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
'read all Text
Dim RAT() As String = System.IO.File.ReadAllLines(Path, System.Text.Encoding.UTF8)
If RAT.Length = 0 OrElse RAT.Length = 1 Then
MessageBox.Show("The File only contains 0 or 1 characters.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Hand)
Return
End If
allLines.AddRange(RAT)
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Dim Pfad_txt As String = Path.Substring(0, Path.LastIndexOf("\"c)) & "\Data2.txt"
Using txtfile As System.IO.StreamWriter = My.Computer.FileSystem.OpenTextFileWriter(Pfad_txt, True)
For Each Line As String In allLines
txtfile.WriteLine(Line)
Next
txtfile.Close()
End Using
End Sub
End Class
By the way: I use a FolderBrowserDialog in the Button1_Click procedure. This should be done so that the program also runs properly on other PCs. In order to be able to use the FBD, you have to download Microsoft.WindowsAPICodePack.Dialogs in Visual Studio's own Nuget package manager.
how to set Option Strict to On
How to uncheck VB6.
how to install FolderBrowserDialog in Visual Studio
Button1
If you want to use a StreamWriter it should be disposed. Classes in the .net Framework that have a Dispose method may use resources outside of the framework which need to be cleaned up. The classes shield you from these details by provided a Dispose method which must be called to properly do the clean up. Normally this is done with Using blocks.
I used a string builder which saves creating and throwing away a string each time you change the string. You may have heard that strings are immutable (cannot be changed). The StringBuilder class gets around this limitation. It is worth using if you have many changes to your string.
The File class is a .net class that you can use to read or write files. It is not as flexible as the stream classes but it is very easy to use.
Button 2
When you declared your Array, you declared an array with no elements. You cannot add elements to an array with no space for them. As Daniel pointed out, you can use the .net class List(Of T) The T stands for Type. This is very good suggestion when you don't know the number of elements in advance. I stuck with the array idea by assigning the array returned by File.ReadAllLines to the lines variable.
You get the same result by simply reading all the text and displaying it.
Button 3
Again I used the File class here which allows you to complete your task in a single line of code. Using 2 parameters for the String.Join method, the separator string and the array to join, we reproduce the original file.
Private SpeciesPath As String = "C:\Users\maryo\Documents\species1.txt"
Private lines As String()
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim sb As New StringBuilder
sb.AppendLine("Pagasius pangasius")
sb.AppendLine("Meretrix lyrata")
sb.AppendLine("Psetta maxima")
sb.AppendLine("Nephrops norvegicus")
sb.AppendLine("Homarus americanus")
sb.AppendLine("Procambarus clarkii")
File.WriteAllText(SpeciesPath, sb.ToString)
MsgBox("list complete")
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
lines = File.ReadAllLines(SpeciesPath)
MessageBox.Show(String.Join(Environment.NewLine, lines))
'OR
MessageBox.Show(File.ReadAllText(SpeciesPath))
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
File.WriteAllLines("C:\Users\maryo\Documents\species2.txt", lines))
End Sub
So basically I am asking how to check if the URL of the webbrowser has changed (is diferrent from the previous one).
Thank you.
You can check ...
Sub webbrowser1_Complete(ByVal sender As Object, _
ByVal e As WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
//Webbrowser1.url property to get valu of url
End Sub
Ok from what I can understand from your question this is what I would do. First create a structurethis will allow you to store data that you may want to use again. Next create a Function in this case with a Boolean return that checks to see if WebBrowser1's current url is the same as the one we have stored within our structure.And once you have done that, I would create a new WebBrowser1 Event in this case WebBrowser1_DocumentCompleted to trigger the Function to compare both the WebBrowser1 url textbox and the structures stored string when a web page as completely loaded.
Public Class Form1
Dim urlSettings As urlSetting
Structure urlSetting
Public url As String
End Structure
Private Function checkURL(url As String) As Boolean
Dim changed As Boolean = True
If Not urlSettings.url = url Then
changed = False
End If
Return changed
End Function
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
WebBrowser1.Navigate(New Uri(TextBox1.Text))
End Sub
Private Sub WebBrowser1_DocumentCompleted(sender As Object, e As WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
If Not checkURL(TextBox1.Text) Then
urlSettings.url = TextBox1.Text
MessageBox.Show("The URL has changed")
End If
End Sub
End Class
Of course you can modify so suit your needs, however this should get you on your way. :) MSDN Information Structure: https://msdn.microsoft.com/en-us/library/4ft0z102.aspx WebBrowser Control : https://msdn.microsoft.com/en-us/library/system.windows.forms.webbrowser(v=vs.110).aspx Return Statesments eg Function: https://msdn.microsoft.com/en-us/library/2e34641s.aspx
So basically I'm trying to create a file manager, and I'm failing at it. I've attempted to find out and haven't found a single response on why I get a (Collection) when I'm loading file names from zip / rar files.
The code is as follows
Imports System.IO
Public Class Form1
Private Sub modFolderButton_Click(sender As Object, e As EventArgs) Handles modFolderButton.Click
Dim modFolder
modFolder = modFolderText.Text
If IO.Directory.Exists(modFolder) Then
MsgBox("Location Successfully Set; " + modFolder, MsgBoxStyle.Information)
Else
MsgBox("Error; Invalid Location Set")
Exit Sub
End If
End Sub
Private Sub starboundButton_Click(sender As Object, e As EventArgs) Handles starboundButton.Click
Dim starboundFolder
starboundFolder = starboundFolderText.Text
If IO.Directory.Exists(starboundfolder) Then
MsgBox("Location Successfully Set; " + starboundFolder, MsgBoxStyle.Information)
Else
MsgBox("Error; Invalid Location Set")
Exit Sub
End If
End Sub
Private Sub listRefreshButton_Click(sender As Object, e As EventArgs) Handles listrRefreshButton.Click
Dim modFolder
Dim listModsDetected
modsDetectedList.Items.Clear()
modFolder = "C:\"
listModsDetected = My.Computer.FileSystem.GetFiles(modFolder, FileIO.SearchOption.SearchTopLevelOnly, "*.zip")
modsDetectedList.Items.Add("None Detected!")
For Each fileName As String In listModsDetected
modsDetectedList.Items.Remove("None Detected!")
modsDetectedList.Items.Add(listModsDetected)
Next
End Sub
End Class
modsDetectedList.Items.Add(listModsDetected)
You just added the collection itself to your list.
That's why it shows (collection).
You probably want to add each item in the collection to your list.
That's what For Each gives you in fileName.
You're adding:
modsDetectedList.Items.Add(listModsDetected)
Eho's ToString is its typename.
Instead use modsDetectedList.Items.AddRange (if it exists) or add the filename in the loop.
I am new here, and relatively new to VB.NET. I have a specific problem with getting my StreamWriter to work properly. One of the requirements of my project is to give the file a default name when the user clicks the Save button, which I have done by setting mysave.Filename = "MyLog.log". I call a new instance of my streamwriter trying to save to the filename specified by the user (mySave.Filename again), but every time, it saves to the default MyLog.log file. I have pasted my code below.
If someone could tell me how I can make sure the data is being saved to the value entered by the user for File name, that would be greatly beneficial. Also, I apologize for the code format, its not perfectly readable, but I'm trying to learn how to use the 4 space indents to my advantage!!
Thanks!
Imports System.IO
Public Class Form1
Dim Initial As String = "C:\Users\Brian Frick\Documents\Visual Studio 2010\Projects\HW5_Frick_Creator\HW5_Frick_Creator\bin\Debug" 'give variable for full path without log file
Dim Fullpath As String = "C:\Users\Brian Frick\Documents\Visual Studio 2010\Projects\HW5_Frick_Creator\HW5_Frick_Creator\bin\Debug\MyLog.log" 'give one path for full path
Dim filewriter As New StreamWriter(Fullpath, True)
Private Sub ExitToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitToolStripMenuItem.Click
Application.Exit() ' quit application
filewriter.Close()
End Sub
Private Sub SaveToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SaveToolStripMenuItem.Click
Dim mySave As New SaveFileDialog
mySave.Filter = "LOG File (*.log)|*.log" 'set filter to .log
mySave.DefaultExt = "log" 'set default extension
mySave.InitialDirectory = Initial 'set default directory
mySave.FileName = "MyLog.log"
mySave.OverwritePrompt = True ' make sure to ask user if they want to over write
If mySave.ShowDialog() = DialogResult.OK Then
Dim filewriter As New StreamWriter(mySave.FileName, True)
filewriter.Close()
'filewriter = New StreamWriter(mySave.FileName, True)
'filewriter.Close() 'close filewriter to allow access to write directory
'Dim Stream As New StreamWriter(mySave.FileName, True) 'save file to path chosen by user in SaveDialog
'Stream.Close() ' Close stream to allow access to directory
' filewriter.Close()
Else
'dialog cancelled - no action
End If
filewriter.Close()
filewriter = New StreamWriter(Fullpath, True) 're initiate filewriter to be used in successive iterations through the program without error
End Sub
Private Sub SavingsDepositBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SavingsDepositBtn.Click
'write to file for SavDep
filewriter.WriteLine("SavDep")
filewriter.WriteLine(AccountBox.Text)
filewriter.WriteLine(AmountBox.Text)
End Sub
Private Sub SavingsWithdrawBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SavingsWithdrawBtn.Click
'write to file for SavWith
filewriter.WriteLine("SavWith")
filewriter.WriteLine(AccountBox.Text)
filewriter.WriteLine(AmountBox.Text)
End Sub
Private Sub CheckDepsotBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckDepsotBtn.Click
'write to file for CheckDep
filewriter.WriteLine("CheckDep")
filewriter.WriteLine(AccountBox.Text)
filewriter.WriteLine(AmountBox.Text)
End Sub
Private Sub CheckWithdrawBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckWithdrawBtn.Click
'write to file for CheckWith
filewriter.WriteLine("CheckWith")
filewriter.WriteLine(AccountBox.Text)
filewriter.WriteLine(AmountBox.Text)
End Sub
End Class
the general way you are using the filewriter won't work, and there are some other serious issues like that there are two 'FileWriter' variables with overlapping scope.
for your save routine, you can't just re-instantiate your filewriter to point it to a different path. that will destroy all the data that had been in the underlying stream, so you are just saving nothing.
try caching the data in memory while the program is running, and don't create the stream until you are ready to write all the data to it, and it to a file, all in one go. your current approach makes it very hard to prevent leaking handles to the log files, so if the app crashes the user will have to reboot to release the write lock before they can run it again. look into the 'using' construct and 'Try... Finally'
I would like to have my variable in .txt file. I've never done it before (I mean putting variable in .txt file). What should my file consist?
And what should I put into my vb project, when I want to use If function.
ex. my variable name = dzien
value= 0
Private Sub zapisz_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles zapisz.Click
Open "C:\Plik.txt" For Append As #1
If dzien = 0 Then
TextBlock1.txt += "dzien jest 0"
End IF
Does this function work if in .txt file there is my variable?
There are multiple ways to do this. For instance, you could store the value in a text file, a binary file, an XML file, an ini file, or a configuration file. The simplest option is to use the built-in settings framework. To do that, go to your project properties and click on the settings tab. Create a new setting called "DZien" and set the type to an integer. Then, in code, you can access and set the value in the config file like this:
Dim dzein As Integer = My.Settings.Dzien.ToString() ' Read value from config file
My.Settings.Dzien = 5 ' Write new value to config file
Rather, if you want to store a single number in a text file, you could do it like this:
Dim dzein As Integer = Integer.Parse(File.ReadAllText("C:\Plik.txt")) ' Read value from text file
File.WriteAllText("C:\Plik.txt", dzein.ToString())
In your case, where you are writing a windows phone app, you could do it like this:
Partial Public Class_1
Inherits PhoneApplicationPage
Private dzien As Integer
Public Sub New()
InitializeComponent()
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles Button2.Click
Try
dzien = CInt(IsolatedStorageSettings.ApplicationSettings("dzien"))
Catch ex As KeyNotFoundException
dzien = 0
End Try
If dzien = 0 Then
' ...
End If
End Sub
Private Sub Class_1_Unloaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Unloaded
IsolatedStorageSettings.ApplicationSettings("dzien") = dzien
End Sub
End Class