I currently have the following code:
Public Class CPUForm
Dim myCPUList As New List(Of CPUClass)
Dim Counter As Integer = 0
Private Sub CPUForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
OpenFileDialog.ShowDialog()
Try
If IO.File.Exists(OpenFileDialog.FileName) = False Then
End If
Catch ex As IO.FileNotFoundException
MessageBox.Show("The File Could Not Be Found", "Alert")
End Try
If IO.File.Exists(OpenFileDialog.FileName) = True Then
Dim sr As IO.StreamReader = IO.File.OpenText(OpenFileDialog.FileName)
Dim line As Object
Dim data() As Object
Do Until sr.EndOfStream
line = sr.ReadLine
data = line.Split(",")
Dim ACpu As New CPUClass(data(0), data(1), data(2), data(3), data(4), data(5))
myCPUList(Counter) = ACpu
Counter += 1
Loop
sr.Close()
End If
lstOut.DataSource = Nothing
lstOut.DataSource = myCPUList
End Sub
End Class
The goal here is to read-in values from a comma separated text file, create objects of the class, add those objects to the collection, and then display the collection in a listbox using an overridden ToString method.
Right now I get no errors, even at runtime. The problem is that one the file is selected, nothing happens. Nothing is displayed in the listbox as if nothing was added to the collection. Also, an overloaded constructor exists to receive the values being read in.
Turns out the code is fine, the problem was an out of place comma in the text file.
Related
Can somebody help me with this, im stuck no idea what to do next
give a text file at any location in the computer it contains 15 different integers that can be repeated
make the program so that multiple repetitions of one number are not printed separately, but each number is printed exactly once
and next to it are written in which places he appeared
Imports System.IO
Public Class form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim povratnaVrijednost As DialogResult
Dim nazivDatoteke As String
Try
OpenFileDialog1.AddExtension = True
OpenFileDialog1.Multiselect = False
OpenFileDialog1.Filter = "Tekst datoteke (*.txt)|*.txt;"
povratnaVrijednost = OpenFileDialog1.ShowDialog()
If povratnaVrijednost = Windows.Forms.DialogResult.OK Then
If OpenFileDialog1.CheckFileExists = True And
OpenFileDialog1.CheckPathExists = True Then
nazivDatoteke = OpenFileDialog1.FileName
TextBox1.Text = nazivDatoteke
Dim citac As New StreamReader(nazivDatoteke)
Dim redTeksta As String = ""
Do
redTeksta = citac.ReadLine()
If Not redTeksta Is Nothing Then
RichTextBox1.Text = RichTextBox1.Text + redTeksta
End If
Loop Until redTeksta Is Nothing
citac.Close()
End If
End If
Catch ex As Exception
MsgBox("Greska prilikom otvaranja" + ex.StackTrace.ToString)
End Try
End Sub
End Class
123
Requirement #1:
give a text file at any location in the computer it contains 15 different integers that can be repeated
This requirement implies a couple of other requirements. First, you're expected to read the text file. Second, you're expected to parse the values into numbers (presumably integers).
You can use an OpenFileDialog (documentation) and specify that it can only accept text files:
Using browseFileDialog = New OpenFileDialog()
With browseFileDialog
.Filter = "*.txt|*.txt"
If (.ShowDialog() = DialogResult.Ok) Then
'.FileName will be the text file that the user picked
End If
End With
End Using
To read the text file, assuming you want each line, use the File.ReadAllLines method (documentation):
Using browseFileDialog = New OpenFileDialog()
With browseFileDialog
.Filter = "*.txt|*.txt"
If (.ShowDialog() = DialogResult.Ok) Then
Dim lines = IO.File.ReadAllLines(.FileName)
End If
End With
End Using
To parse the values, use the Array.ConvertAll method (documentation) and inside of the predicate use the Integer.Parse method (documentation):
Using browseFileDialog = New OpenFileDialog()
With browseFileDialog
.Filter = "*.txt|*.txt"
If (.ShowDialog() = DialogResult.Ok) Then
Dim lines = IO.File.ReadAllLines(.FileName)
Dim values = Array.ConvertAll(lines, Function(line) Integer.Parse(line))
End If
End With
End Using
Keep in mind that if you wanted to validate that the lines are all valid numbers, instead of assuming that they are, this step would be different. However, you didn't specify that requirement in your original post so I'm not including how to do that.
Requirement #2:
make the program so that multiple repetitions of one number are not printed separately, but each number is printed exactly once
You can use the Random.Next method (documentation) to generate random values. Be sure to declare the new instance of the random object once so that the seed is only set once. To randomly order the values, use the OrderBy method (documentation) passing the random value in the predicate:
Private ReadOnly _random As New Random()
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Using browseFileDialog = New OpenFileDialog()
With browseFileDialog
.Filter = "*.txt|*.txt"
If (.ShowDialog() = DialogResult.Ok) Then
Dim lines = IO.File.ReadAllLines(.FileName)
Dim values = Array.ConvertAll(lines, Function(line) Integer.Parse(line))
Dim randomlyOrderedValues = values.OrderBy(Function(value) _random.Next())
RichTextBox1.Text = String.Join(", ", randomlyOrderedValues.ToArray())
End If
End With
End Using
End Sub
Default for .AddExtension is True. Default for .Multiselect is False. I have simplified the If statement by comparing the return value of .Showdialog directly to the desired DialogResult. If the path of file don't exist the dialog will show a waring.
Always scope variables as narrowly as possible. I move the Dim nazivDatoteke to inside the If since it is not used anywhere else. StreamReaders require a Using block since they need to be disposed.
Why a RichTextBox for a text file?
As you can see getting the distince items in the array is easy, a single line of code. What is more difficult is finding the indexes in the original array, lines.
I looped through all the items in the distinct array (actually it is an IEnumerable(Of String) but that is not important to this code, it is just easier to type array in my explanation). I created a List(Of Integer) to hold the indexes of each item in the original array, lines. The startIndex where the FindIndex method of an Array is the location of the first occurrence of the String.
On each iteration of the Do loop I look for the matches to the item from the lines array. The FindIndex takes parameters (original array, index to start at, what we are looking for). It stops as soon as it finds a match and returns -1 if no matches are found. You can see the operation of this method be setting a break point and checking the variable values.
If a match is found I added that value to the list and change the startIndex to the position following the found index.
Next I used a StringBuilder to create the string to display. I chose the immediate window for testing purposes but you could show sb.ToString in a text box or add it to a ListBox.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
OpenFileDialog1.Filter = "Tekst datoteke (*.txt)|*.txt;"
If DialogResult.OK = OpenFileDialog1.ShowDialog Then
Dim nazivDatoteke = OpenFileDialog1.FileName
TextBox1.Text = nazivDatoteke
Dim lines = File.ReadAllLines(nazivDatoteke)
Dim distinct = lines.Distinct
For Each item In distinct
Dim lst As New List(Of Integer)
Dim startIndex = Array.IndexOf(lines, item)
Do
Dim FoundIndex = Array.FindIndex(lines, startIndex, Function(line) line = item)
If FoundIndex = -1 Then
Exit Do
Else
lst.Add(FoundIndex)
startIndex = FoundIndex + 1
End If
Loop
Dim sb As New StringBuilder
sb.Append(item)
For Each i In lst
sb.Append($" ({i})")
Next
Debug.Print(sb.ToString)
Next
End If
End Sub
This code displays the distinct items in the list and follow it with the positions (indexes) in the original list.
What I want to do is import a CSV file (called fwlist.txt), that looks like this:
modelname,power type,pic,part number,firmware, option1, option 1, etc
End result, i would like a combobox that shows the modelname, and when the model name is selected from the pulldown, it updates various labels and text boxes on the form with other information.
Here's what I have so far:
Dim filename As String = "fwlist.txt"
Dim pwrtype As String
Dim pic As String
Dim partnum As String
Dim lineread As String
Dim FirmwareName As String
Private Sub ReadFirmwaresLoad(sender As Object, e As EventArgs) Handles Me.Load
' Load the items into the NameComboBox list.
Dim ResponseDialogResult As DialogResult
Try
Dim FirmwareStreamReader As StreamReader = New StreamReader(filename)
' Read all the elements into the list.
Do Until FirmwareStreamReader.Peek = -1
lineread = FirmwareStreamReader.ReadLine()
Dim fields As String() = lineread.Split(",")
FirmwareName = fields(0) 'Take First Field
cbFW.Items.Add(FirmwareName)
'Set Text labels based on position in line.
pwrtype = fields(1)
pic = fields(2)
partnum = fields(3)
(...etc through options)
Loop
' Close the file.
FirmwareStreamReader.Close()
Catch ex As Exception
' File missing.
ResponseDialogResult = MessageBox.Show("File not Found!", "File Not Found",
MessageBoxButtons.OK, MessageBoxIcon.Question)
If ResponseDialogResult = DialogResult.OK Then
' Exit the program.
Me.Close()
End If
End Try
End Sub
Private Sub cbFW_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cbFW.SelectedIndexChanged
lblPwrType.Text = pwrtype
lblPic.Text = pic
lblPartNum.Text = parnum
....etc thruogh options
End Sub
This code works, but only sort of. If i select anything from the combo box, it only gives me the information from the very last line of the CSV file - even if its the first entry in the box. I'm pretty sure it's something simple that I'm messing up.. anyone help?
First we read the lines into Firmware objects then we set this List(Of Firmware) as the DataSource of the ComboBox.
Then we handle the SelectedIndexChanged event of the ComboBox which will get the currently selected firmware and loads its data to the TextBox controls.
This is a tested, working example below:
Public Class Firmware
Public Property ModelName As String
Public Property PowerType As String
Public Property Pic As String
Public Property PartNumber As String
Public Property Firmware As String
Public Property Option1 As String
End Class
Public Class MainForm
Private Sub btnLoad_Click(sender As Object, e As EventArgs) Handles btnLoad.Click
Dim lines As String() = Nothing
Try
' Read the file in one step
lines = File.ReadAllLines("fwlist.txt")
Catch ex As Exception
Dim dialogResult As DialogResult = MessageBox.Show(Me, "File not found! Would you like to exit program?", "Error reading file", MessageBoxButtons.YesNo, MessageBoxIcon.Error, MessageBoxDefaultButton.Button2)
If dialogResult = DialogResult.Yes Then
Me.Close()
End If
Exit Sub
End Try
Dim firmwares As List(Of Firmware) = New List(Of Firmware)
For Each line As String In lines
Dim rawData As String() = line.Split({","}, StringSplitOptions.None)
' Create Firmware object from each line
Dim firmware As Firmware = New Firmware() With
{
.ModelName = rawData(0),
.PowerType = rawData(1),
.Pic = rawData(2),
.PartNumber = rawData(3),
.Firmware = rawData(4),
.Option1 = rawData(5)
}
' We store the read firmwares into a list
firmwares.Add(firmware)
Next
' Set the list as the data source of the combobox
' DisplayMember indicates which property will be shown in the combobox
With cboModelNames
.DataSource = firmwares
.DisplayMember = "ModelName"
End With
End Sub
Private Sub cboModelNames_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboModelNames.SelectedIndexChanged
RefreshForm()
End Sub
Private Sub RefreshForm()
' Get the selected item as Firmware object
Dim currentFirmware As Firmware = DirectCast(cboModelNames.SelectedItem, Firmware)
' Refresh all the textboxes with the information
With currentFirmware
txtPowerType.Text = .PowerType
txtPic.Text = .Pic
txtPartNumber.Text = .PartNumber
txtFirmware.Text = .Firmware
txtOption1.Text = .Option1
End With
End Sub
End Class
Every time you set the value of a variable like pwrtype, its old value is thrown away and there is no way to get it back. And even if you did save multiple values for each variable, you would need a way to figure out which value goes with the currently selected item in the combo box. To resolve these two issues you need:
a way to group values from the same line together
a way to save all values read from the file, not just the most recent ones
Let's start with the first issue, grouping values together. In the example code below, I created a Structure type called FirmwareInfo to serve that purpose. Each FirmwareInfo has its own pwrtype, pic, etc.
The other piece of the puzzle that you are missing is a way to save more than one Firmware. The easiest way to do this is to add each FirmwareInfo to the combo box's item list, instead of adding just the display string. The combo box will convert each item to a string in the UI; the ToString() method tells it how you want this conversion to be done.
I haven't run this example code so I can't guarantee there aren't mistakes in there, but hopefully it's enough to show the general idea.
Dim filename As String = "fwlist.txt"
Structure FirmwareInfo
Public pwrtype As String
Public pic As String
Public partnum As String
Public FirmwareName As String
Public Overrides Function ToString() As String
Return FirmwareName
End Function
End Structure
Private Sub ReadFirmwaresLoad(sender As Object, e As EventArgs) Handles Me.Load
' Load the items into the NameComboBox list.
Dim ResponseDialogResult As DialogResult
Try
Dim FirmwareStreamReader As StreamReader = New StreamReader(filename)
' Read all the elements into the list.
Do Until FirmwareStreamReader.Peek = -1
Dim lineread = FirmwareStreamReader.ReadLine()
Dim fields As String() = lineread.Split(",")
Dim info As New FirmwareInfo With {
.FirmwareName = fields(0),
.pwrtype = fields(1),
.pic = fields(2),
.partnum = fields(3)
}
cbFW.Items.Add(info)
Loop
' Close the file.
FirmwareStreamReader.Close()
Catch ex As Exception
' File missing.
ResponseDialogResult = MessageBox.Show("File not Found!", "File Not Found",
MessageBoxButtons.OK, MessageBoxIcon.Question)
If ResponseDialogResult = DialogResult.OK Then
' Exit the program.
Me.Close()
End If
End Try
End Sub
Private Sub cbFW_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cbFW.SelectedIndexChanged
Dim currentInfo = DirectCast(cbFW.SelectedItem, FirmwareInfo)
lblPwrType.Text = currentInfo.pwrtype
lblPic.Text = currentInfo.pic
lblPartNum.Text = currentInfo.parnum
' ....etc through options
End Sub
I'm currently designing an application within visual basic using vb.net. The first form asks for login information and then prompts the next form to select a customer. The customer information is stored in a text file that gets put in an array. I next have a form for the user to display and edit that information. How can I use the array I already created in the previous form in my display and edit form?
Private Sub frmCustomerList_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim sr As StreamReader = File.OpenText("customer.txt")
Dim strLine As String
Dim customerInfo() As String
Do While sr.Peek <> -1
strLine = sr.ReadLine
customerInfo = strLine.Split("|")
cboCustomers.Items.Add(customerInfo(0))
customerList(count) = strLine
count = count + 1
Loop
End Sub
Private Sub cboCustomers_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboCustomers.SelectedIndexChanged
Dim customerInfo() As String
Dim index As Integer = cboCustomers.SelectedIndex
Dim selectedCustomer As String = customerList(index)
customerInfo = selectedCustomer.Split("|")
End Sub
Make the next form require it in the constructor:
Public Class EditCustomer
Public Sub New(customerInfo As String())
InitializeComponent() 'This call is required, do not remove
'Yay! Now you have your info
End Sub
End Class
You'd call it by doing something like...
Dim editForm = New EditCustomerFrom(customerInfo)
editForm.Show()
Alternatively, you could have a property on the form you set.
Dim editForm = New EditCustomerFrom()
editForm.Customer = customerInfo
editForm.Show()
Then inside the Load event of that form, you'd write the logic that would display it looking at that property.
Aside: You should look at maybe defining an object to hold customer info and do some JSON or XML serialization for reading/writing to the file, IMO. This architecture is kind of not good as is....
Here is my code:
Private Sub btnDisplayOrderDetails_Click(ByVal sender As Object, _
ByVal e As EventArgs) _
Handles btnDisplayOrder Details.Click
Dim myStreamReader As StreamReader
Try
myStreamReader = File.OpenText("Textfile1.txt")
Me.txtOrderDetails.Text = myStreamReader.ReadToEnd()
Catch exc As Exception
Finally
If Not myStreamReader Is Nothing Then
myStreamReader.Close()
End If
End Try
If txtOrderDetails.Text = "" Then
Dim mystreamreader1 As StreamReader
Try
mystreamreader1 = File.OpenText("textfile2.txt")
Me.txtOrderDetails.Text = myStreamReader.ReadToEnd()
Catch ex As Exception
Finally
If Not myStreamReader Is Nothing Then
mystreamreader1.Close()
End If
End Try
End If
End Sub
What I would like this code to do is:
Read the first Text file upon button click, then when I've cleared the text Box (with the use of a different button which is already coded) I would then like to read in the second text file upon button click into the same Text box as before.
It's not clear what you are trying to do with the files. Combine them all into a single text box, or does each file belong to a specific textbox.
The looping method to place all the files into a single text box:
Dim filePath As String = "C:\Users\Practice\Practice\bin\Debug"
Dim sb As New StringBuilder
For Each f As String In Directory.GetFiles(filePath, "*.txt")
sb.AppendLine(File.ReadAllText(f))
Next
txtOrderDetails.Text = sb.ToString()
Or if it's not a list, then you go through your files one by one:
Dim test1 As String = Path.Combine(filePath, "Textbox1.txt")
If File.Exists(test1) Then
TextBox1.Text = File.ReadAllText(test1)
End If
Dim test2 As String = Path.Combine(filePath, "Textbox2.txt")
If File.Exists(test2) Then
TextBox2.Text = File.ReadAllText(test2)
End If
So I feel like im pretty close, but I also have a feeling I am mixing up StreamReader and ReadAllLines
....................................................................................
Option Strict On
Imports System.IO
Public Class Form4
Dim file As System.IO.StreamWriter
Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
file = My.Computer.FileSystem.OpenTextFileWriter("c:\devices.bat", False)
file.WriteLine("#echo off")
file.WriteLine("cd " & Form1.TextBox2.Text)
file.WriteLine("adb devices > C:\devices.txt")
file.Close()
Shell("C:\devices.bat", AppWinStyle.Hide, True, 500)
Dim output() = System.IO.File.ReadAllLines("C:\deviceinfo2.txt")
Dim Devices As String = ""
Dim line() As String = {}
For X = 1 To output.Count = -1
line = output(X).Split(New Char() {(" ")})
Devices = line(0)
ComboBox1.Items.Add(Devices)
Next
output.Close()
output.Dispose()
End Sub
End Class
........................................................................
What I am trying to have it do is to start reading on line two of devices.txt and then read the first word from each line until the text file is done.
It seems simple enough, but like I said, I think I am mixing streamreader with readalllines
Any help is appreciated
Class Test
Public Sub Main()
Try
' Create an instance of StreamReader to read from a file.
' The using statement also closes the StreamReader.
Using sr As New StreamReader("TestFile.txt")
Dim line, firstWord As String
Dim i as Integer = 0
' Read and display lines from the file until the end of
' the file is reached.
Do
line = sr.ReadLine()
If Not (line Is Nothing) AndAlso i > 0 Then
firstWord = line.Split(" ")(i)
'do your logic
End If
i += 1
Loop Until line Is Nothing
End Using
Catch e As Exception
' Let the user know what went wrong.
End Try
End Sub
End Class
Grabbed this from MSDN and modified it. It should compile, but I didn't test it. This will loop through the lines, 1 by 1, skip the first line and grab each line's first word after. Hope this helps.