Let's say I have a Button that, when clicked, will output text ("test text") to a .ini file in directory (C:/configdir) for example. How would I create this .ini file?
Then I have another Button that, when clicked, will show the content ("test text") of the .ini I just created. I am guessing I need to streamwrite the text.
Here's something that will work.
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Using sw As New System.IO.StreamWriter("c:\myfile.ini", False)
sw.WriteLine("test text")
End Using
Using sr As New System.IO.StreamReader("c:\myfile.ini")
Dim Line As String = sr.ReadLine
Do While Line IsNot Nothing
MsgBox(Line)
Loop
End Using
End Sub
Related
I have to run a process - through the execution of a batch script - which produces an output that is saved as a text file. Furthermore, I need to see this output on a form of the application of mine and, to do this, I've set an iterative timer which updates every second the content of a non-editable RichTextBox but I have two issues:
Each time the timer stops and restarts, I need to create a copy the output file, since the file is used from another process and can't be loaded onto the software as it is;
Creating and loading this text file may be honerous in terms of hardware capability, since this file may reach really big size (even more than 5 GB).
Here is the code I'm providing:
Private Sub Form9_Load(sender As Object, e As EventArgs) Handles MyBase.Load
[...]
Me.Timer1.Interval = TimeSpan.FromSeconds(1).TotalMilliseconds
Me.Timer1.Start()
End Sub
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
Application.DoEvents()
Dim p = Process.GetProcessesByName("fds2ftmi_win_64")
Dim appPath As String = Path.GetDirectoryName(Application.ExecutablePath)
If My.Computer.FileSystem.FileExists(Form1.TextBox5.Text + "/HTAoutput.dat") Then
If p.Count > 0 Then
RichTextBox1.Refresh()
My.Computer.FileSystem.CopyFile(Form1.TextBox5.Text + "/HTAoutput.dat", Form1.TextBox5.Text + "/HTAoutemp.dat", Microsoft.VisualBasic.FileIO.UIOption.OnlyErrorDialogs, FileIO.UICancelOption.DoNothing)
RichTextBox1.LoadFile(Form1.TextBox5.Text + "/HTAoutemp.dat", RichTextBoxStreamType.PlainText)
RichTextBox1.SelectionStart = RichTextBox1.TextLength
RichTextBox1.ScrollToCaret()
Else
Call Button3_Click(sender, e)
End If
End If
End Sub
Is there a more efficient way to show this stream-writing onto my log-window?
Thanks all are gonna answer me
EDIT 1:
Here is the code I'm providing:
Dim p = Process.GetProcessesByName("fds2ftmi_win_64")
Dim appPath As String = Path.GetDirectoryName(Application.ExecutablePath)
Dim str As FileStream
str = File.Open(Form1.TextBox5.Text + "/HTAoutput.dat", FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
If My.Computer.FileSystem.FileExists(Form1.TextBox5.Text + "/HTAoutput.dat") Then
If p.Count > 0 Then
RichTextBox1.LoadFile(str, RichTextBoxStreamType.PlainText)
RichTextBox1.SelectionStart = RichTextBox1.TextLength
RichTextBox1.ScrollToCaret()
Application.DoEvents()
Else
Call Button3_Click(sender, e)
End If
End If
Here is a simple demonstration of opening a file once and continuing to read only new data as it is added to that file.
Create a new WinForms Application project with two forms. Add a TextBox and a Button to each form. Make the TextBox multiline on Form1. Add a text file to your project named Test.txt and set Copy to Output Directory to Copy always. Add some default text to the file. Add this code to Form1:
Imports System.IO
Public Class Form1
Private reader As StreamReader
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'Open the file for reading and allow sharing.
Dim filePath = Path.Combine(Application.StartupPath, "Test.txt")
Dim strm = File.Open(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
reader = New StreamReader(strm)
'Read all available text and append to the existing text.
TextBox1.Text = reader.ReadToEnd()
Form2.Show()
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
'Read all available text and append to the existing text.
TextBox1.AppendText(reader.ReadToEnd())
End Sub
End Class
and add this code to Form2:
Imports System.IO
Public Class Form2
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim filePath = Path.Combine(Application.StartupPath, "Test.txt")
'Write a new line of text to the file.
File.AppendAllText(filePath, Environment.NewLine & TextBox1.Text)
'Get ready for the next line of text.
TextBox1.Clear()
TextBox1.Select()
End Sub
End Class
Run the project and you'll see your default text in Form1. Enter some text into Form2 and click the Button. Do that a few times. Now click the Button on Form1. Voila! Repeat that cycle and see the text you enter on one form magically appear on the other.
Now go back and examine the code more closely. You can see that Form2 appends a line of code to the file each time you click the Button. Form1 reads the initial contents of the file when it loads and displays that, but it keeps the file open. Each time you click the Button, it will read only the new data, i.e. only the data after where it previously read up to. It then appends that new text to the existing text in the TextBox.
i have contains listbox. how to export listbox to notepad in vb? Please advise me
Notepad typically reads and writes plain old .txt files. These can be written with a standard StreamWriter. Just iterate over your ListBox and write each item to your file:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim txtFile As String = "C:\Users\mikes\Documents\Test.txt"
Using sw As New IO.StreamWriter(txtFile, False)
For Each item As String In ListBox1.Items
sw.WriteLine(item)
Next
End Using
End Sub
If you don't want to hard-code a filename, then use a SaveFileDialog to get a filename from the user.
How do you use a textbox value for VB to save some text to? This is what I have so far:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles butUpdate.Click
Dim ECOLID As String
ECOLID = txtID.Text
Dim file As System.IO.StreamWriter
file = My.Computer.FileSystem.OpenTextFileWriter("?", True)
file.WriteLine("ECOL Number:")
file.WriteLine(txtID.Text)
file.Close()
End Sub
The txtID text will determine the title however how can I get it to save it as "C:/Order/'txtID'.txt" for example?
A textbox has a property called Name and this is (usually) the same as the variable name that represent the TextBox in your code.
So, if you want to create a file with the same name of your textbox you could write
file = My.Computer.FileSystem.OpenTextFileWriter(txtID.Name & ".txt", True)
However there is a big improvement to make to your code
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles butUpdate.Click
Dim ECOLID As String
ECOLID = txtID.Text
Dim fileName = txtID.Name & ".txt"
Using file = My.Computer.FileSystem.OpenTextFileWriter(fileName, True)
file.WriteLine("ECOL Number:")
file.WriteLine(txtID.Text)
End Using
End Sub
In this version the opening of the StreamWriter object is enclosed in a Using Statement. This is fundamental to correctly release the resources to the operating system when you have done to work with your file because the End Using ensures that your file is closed and disposed correctly also in case of exceptions
Private Sub Button7_Click(sender As Object, e As EventArgs) Handles Button7.Click
Dim CurrentDir As String = Environment.CurrentDirectory
Dim OutputFile2 As String = IO.Path.Combine(CurrentDir, "input.txt")
IO.File.WriteAllLines(OutputFile2, Result1.Lines)
End Sub
Right now, I have coding that saves a text file in the current directory. However, I want to have a browse button for users so that they can pick where this text file is saved. How do I proceed this?
I was trying it by my self and I'm having a trouble with using save file dialog. If you can teach me how to use a save file dialog or anyway to write save browse button, I would very appreciate it!
The documentation for the SaveFileDialog object contains an example.
Here is a tutorial on how to implement SaveFileDialog using Toolbox in Visual Studio like you mentioned. The code sample is in C# but it can be easily converted to VB.
Link: www.dotnetperls.com/savefiledialog
Private Sub button1_Click(sender As Object, e As EventArgs)
' When user clicks button, show the dialog.
saveFileDialog1.ShowDialog()
End Sub
Private Sub saveFileDialog1_FileOk(sender As Object, e As CancelEventArgs)
' Get file name.
Dim name As String = saveFileDialog1.FileName
' Write to the file name selected.
' ... You can write the text from a TextBox instead of a string literal.
File.WriteAllText(name, "test")
End Sub
I am new to Visual Basic.NET and I am just playing around with it. I have a book that tells me how to read from a file but not how to write to the file with a button click. All I have is a button and a textbox named fullNameBox. When I click the button it gives me an unhandled exception error. Here is my code:
Public Class Form1
Sub outputFile()
Dim oWrite As System.IO.StreamWriter
oWrite = System.IO.File.CreateText("C:\sample.txt")
oWrite.WriteLine(fullNameBox.Text)
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
outputFile()
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
End Class
Have you tried stepping through your application to see where the error is? With a quick glance, it looks like you might need to use System.IO.File on the fourth line (oWrite = IO.File...) instead of just IO, but I haven't tried to run it.
Imports System.IO
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
SaveFileDialog1.FileName = ""
SaveFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
SaveFileDialog1.ShowDialog()
If SaveFileDialog1.FileName.Trim.Length <> 0 Then
Dim fs As New FileStream(SaveFileDialog1.FileName.Trim, FileMode.Create)
Dim sr As New StreamWriter(fs)
sr.Write(TextBox1.Text)
fs.Flush()
sr.Close()
fs.Close()
End If
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
OpenFileDialog1.FileName = ""
OpenFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
OpenFileDialog1.ShowDialog()
If OpenFileDialog1.FileName.Trim.Length <> 0 Then
Dim fs As New FileStream(OpenFileDialog1.FileName.Trim, FileMode.Open)
Dim sw As New StreamReader(fs)
TextBox1.Text = sw.ReadToEnd
fs.Flush()
sw.Close()
fs.Close()
End If
End Sub
End Class
this is a complete functional program if you want, you just need to drag drop a textbox, openfiledialog, and a savefiledialog.
feel free to play around with the code.
enjoy
by the way, the problem in your code is that you "must" close filestream when your done using it, doing so will release any resource such as sockets and file handles.
The .net framework is a very powerful framework. In the same way (however) it has easy and convenient methods for simple tasks. Most individuals tend to complicate things in order to display knowledge. But less code = less processing = faster and more efficient application (sometimes) so the large above method may not be suitable. Along with that, the above mentioned method would be better off written as a sub or if returning something then a function.
My.Computer.FileSystem.WriteAllText("File As String", "TextAsString", Append as Boolean)
A general Example would be
My.Computer.FileSystem.WriteAllText("C:\text.text", "this is what I would like to add", False)
this is what I would like to add
can be changed to the current text of a field as well.
so a more specific example would be
My.Computer.FileSystem.WriteAllText("C:\text.text", fullNameBox.text, True)
If you would like to understand the append part of the code
By setting append = true you are allowing your application to write the text at the end of file, leaving the rest of the text already in the file intact.
By setting append = false you will be removing and replacing all the text in the existing file with the new text
If you don't feel like writing that part of the code (though it is small) you could create a sub to handle it, however that method would be slightly different, just for etiquette. functionality would remain similar. (Using StreamWriter)
Private Sub WriteText()
Dim objWriter As New System.IO.StreamWriter("file.txt", append as boolean)
objWriter.WriteLine(textboxname.Text)
objWriter.Close()
End Sub
The Specific Example would be
Private Sub WriteText()
Dim objWriter As New System.IO.StreamWriter("file.txt", False)
objWriter.WriteLine(fullnamebox.Text)
objWriter.Close()
End Sub
then under the button_click event call:
writetext()
You can take this a step further as well. If you would like to create a more advabced Sub to handle any textbox and file.
Lets say you plan on having multiple separate files and multiple fields for each file (though there is a MUCH cleaner more elegant method) you could create a function. {i'll explain the concept behind the function as thoroughly as possible for this example}
below is a more advanced sub demonstration for your above request
Private Sub WriteText(Filename As String, app As Boolean, text As String)
Dim objWriter As New System.IO.StreamWriter(Filename, app)
objWriter.WriteLine(text)
objWriter.Close()
End Sub
What this does is allows us to (on the same form - if you need it global we can discuss that another time, it's not much more complex at all) call the function and input the information as needed.
Sub Use -> General Sample
WriteText(Filename As String, app As Boolean)
Sub Use -> Specific Sample
WriteText("C:\text.txt, False, fullnamebox.text)
But the best part about this method is you can change that to be anything as you need it.
Let's say you have Two Buttons* and **Two Boxes you can have the button_event for the first button trigger the above code and the second button trigger a different code.
Example
WriteText("C:\text2.txt, False, halfnamebox.text)
The best part about creating your own functions and subs are Control I won't get into it, because it will be off topic, but you could check to be sure the textbox has text first before writing the file. This will protect the files integrity.
Hope this helps!
Richard Sites.