I want to read the value given by user in text box in vb.net.
if they give value ABC , i want to read the string one by one and display the particular character(ex. 3rd character(c)) in another text box.
Assuming you have 2 text boxes and a button:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim textBox1InputString As String
textBox1InputString = TextBox1.Text
' Call ToCharArray function.
Dim array() As Char = textBox1InputString.ToCharArray
' If we input ABC and we want C
TextBox2.Text = array(2)
End Sub
For i = 0 To TextBox1.Text.Length
If i = 2 Then
TextBox2.Text = TextBox1.Text(i)
End If
Next
Related
I want to Count how many times I click a button and display the number, but the format should be like: 0001 if reach 9999 restart to 0001 again and count till 9999.
I tried:
Private ButtonClickCount As Integer = 0
ButtonClickCount += 1
Label5.Text = "0000" & ButtonClickCount
And
Label5.Text = "0000" + Val(Label5.Text) + 1
This was the dumbest way I tried.lol
And the result was disapointing.
Is there any easy way to do it?
If you use a Static variable for the count, you can keep it in the button click event handler. (Static variables aren't used all that often, but it works here, assuming you don't need the variable anywhere else.)
If you check if the counter has reached 10000, you can set it back to 1.
You can format the number in the .ToString method.
Perhaps something like this:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Static clickCount As Integer = 0
clickCount += 1
If clickCount = 10000 Then
clickCount = 1
End If
lblClickCount.Text = clickCount.ToString("0000")
End Sub
You could use the Format command, which controls how many zeroes you want in the output:
Dim ButtonClicks As Integer = 0
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
ButtonClicks += 1
Label1.Text = Format(ButtonClicks, "0000")
End Sub
Dim ButtonClicks As Integer = 0
Private sub Button1_click(sender as object, e as EventArgs) handles Button 1.click
Buttonclick +=1
If buttonclick ="9999" then
Buttonlclick=1
Endif
Label1.text =format(Buttonclick, "0000")
End sub
You will need to keep track of the counter somewhere, in this case I would suggest storing the counter in the control's Tag property (documentation). In your button's click event, you would do the following:
Get the Tag
Convert the value to an Integer
Increment the value by 1
Check if the new value is greater than 9999
Optionally reset the value to 1 if 4 is true
Set the Text of the Button to the formatted result
Set the Tag of the button to the new value
Here is an example:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim clickedButton = DirectCast(sender, Button)
Dim tagValue = clickedButton.Tag
If (tagValue Is Nothing) Then
tagValue = 0
End If
Dim conversion As Integer
If (Not Integer.TryParse(tagValue.ToString(), conversion)) Then
conversion = 0
End If
conversion += 1
If (conversion > 9999) Then
conversion = 1
End If
clickedButton.Text = converstion.ToString("0000")
clickedButton.Tag = conversion
End Sub
Well, sorry guys, just realized that I could use the PadLeft function... And worked fine.
ButtonClickCount += 1
Label5.Text = ButtonClickCount.ToString().PadLeft(5, "0")
But Still don't know if it reaches 9999 will restart from 0001
sorry I'm a newbie and I'm trying to write a program to get ten integers from user with a an Inputbox or Textbox and displays the biggest and lowest one in a label with visual basic. I'll be appreciated if you help me out with this.
Thank you. this is my solution. I don't know how to compare these ten numbers with each other.
Private Sub btnShow_Click(sender As Object, e As EventArgs) Handles btnShow.Click
Dim i, Container, Max, Numbers
Max = 0
i = 1
While (i <= 10)
Numbers = InputBox("please enter a number", "Enter a number")
Max = Numbers
Container = Container & " " & Numbers
i = i + 1
End While
lblresult.Text = Container
End Sub
conceptually speaking you should use a List(Of Integer) or List(Of Double), perform the loop 10 times adding the value into the list.
Suppose this is our list
Dim container As New List(Of Integer)
To get input
Dim userInput = ""
Dim input As Integer
userInput = InputBox("please enter a number", "Enter a number")
If Integer.TryParse(userInput, input) Then
container.Add(input)
End If
After the loop
Console.WriteLine($"Min: {container.Min()} Max: {container.Max()}")
Does this make sense to you ?
Edit, based on asking for Windows Forms example.
You could do the following instead of a InputBox, requires a label, a button and a TextBox.
Public Class MainForm
Private container As New List(Of Integer)
Private Sub CurrentInputTextBox_KeyPress(sender As Object, e As KeyPressEventArgs) _
Handles CurrentInputTextBox.KeyPress
If Asc(e.KeyChar) <> 8 Then
If Asc(e.KeyChar) < 48 Or Asc(e.KeyChar) > 57 Then
e.Handled = True
End If
End If
End Sub
Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles Me.Shown
CurrentLabel.Text = "Enter number 1"
End Sub
Private Sub ContinueButton_Click(sender As Object, e As EventArgs) _
Handles ContinueButton.Click
If Not String.IsNullOrWhiteSpace(CurrentInputTextBox.Text) Then
container.Add(CInt(CurrentInputTextBox.Text))
CurrentLabel.Text = $"Enter number {container.Count + 1}"
If container.Count = 10 Then
ContinueButton.Enabled = False
CurrentLabel.Text =
$"Count: {container.Count} " &
$"Max: {container.Max()} " &
$"Min: {container.Min()}"
Else
ActiveControl = CurrentInputTextBox
CurrentInputTextBox.Text = ""
End If
End If
End Sub
End Class
I really didn't want to do your homework for you but I was afraid you might be hopelesly confused.
First let's go over your code. See comments
Private Sub btnShow_Click(sender As Object, e As EventArgs) Handles btnShow.Click
Dim i, Container, Max, Numbers 'Don't declare variables without an As clause
Max = 0 'Max is an object
i = 1 'i is and object
While i <= 10 'the parenthesis are unnecessary. You can't use <= 2 with an object
Numbers = InputBox("please enter a number", "Enter a number")
Max = Numbers
Container = Container & " " & Numbers 'Container is an object; you can't use & with an object
i = i + 1 'Again with the object i can't use +
End While
lblresult.Text = Container
End Sub
Now my approach.
I created a List(Of T) at the Form level so it can be seen from different procedures. The T stands for type. I could be a built in type or type you create by creating a Class.
The first click event fills the list with the inputted numbers. I used .TryParse to test if the input is a correct value. The first parameter is a string; the input from the user. The second parameter is a variable to hold the converted string. .TryParse is very clever. It returns True or False base on whether the input string can be converted to the correct type and it fills the second parameter with the converted value.
The second click event loops through the list building a string to display in Label1. Then we use methods available to List(Of T) to get the numbers you desire.
Private NumbersList As New List(Of Integer)
Private Sub FillNumberList_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim i As Integer
While i < 10
Dim input = InputBox("Please enter a whole number")
Dim inputInt As Integer
If Integer.TryParse(input, inputInt) Then
NumbersList.Add(inputInt)
i += 1 'We only increment i if the parse is succesful
End If
End While
MessageBox.Show("Finished Input")
End Sub
Private Sub DisplayResults_Click(sender As Object, e As EventArgs) Handles Button2.Click
Label1.Text = "You input these numbers "
For Each num In NumbersList
Label1.Text &= $"{num}, "
Next
Label2.Text = $"The largest number is {NumbersList.Max}"
Label3.Text = $"The smallest number is {NumbersList.Min}"
End Sub
Complete noob to vb.net (and programming in general) here, all I really want is every time I click a button, the number in the textbox is added by 1 but the new number shows up on the next line. Tried to google this a hundred times but nothing really helped.
I don't want to use loops as I don't want all numbers to show up at once, only for the added number to show up after clicking a specific button (on a new line).
Public Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim txtoutput As String = ""
Dim a As Integer = 1
txtoutput &= "the value of a =" & a & Environment.NewLine
a = a + 1
TextBox1.Text = txtoutput
End Sub
You are replacing the Text, you want to append a new line, so you need to do:
Private a As Int32 = 0
Public Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
a += 1
Dim newLine = $"the value of a = {a}"
TextBox1.Text = TextBox1.Text & Environment.NewLine & newLine
End Sub
You also have to use a field and not a local variable if you want to retain the old value and increment it. Otherwise it is reset always to it's inital value.
Please try to change dim a to static a
Public Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim txtoutput As String = ""
Static a As Integer = 1
txtoutput &= "the value of a =" & a & Environment.NewLine
a = a + 1
TextBox1.Text = txtoutput
End Sub
For example i got two barcode, so i scan the two barcode at the textbox, it appear AVM12323AVM44454..
But I want it to be displayed in textbox for example like AVM12323, AVM44454. where there is a "," comma between the two code.
Previously i'm only tested for scan one barcode only in the textbox. So now i'm trying to scan more than one barcode in one textbox.
i have been looking the few example but not success.
Private Sub TextBoxMulti_TextChanged(sender As Object, e As EventArgs) Handles TextBoxMulti.TextChanged
Dim selectedMultiArrayScan As String()
Dim selectedMultiScan As String = ""
selectedMultiScan = TextBoxMulti.Text & ","
selectedMultiArrayScan = selectedMultiScan.Split(",")
End Sub
Private Sub MultiScan_Click(sender As Object, e As EventArgs) Handles MultiScan.Click
For Each stateName As String In selectedMultiArrayScan
//some query for each scanned item
Next stateName
End Sub
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
Timer1.Enabled = False ' Fire only once
If TextBox1.Text.Trim <> "" Then TextBox1.Text += ", "
End Sub
Private Sub TextBox1_KeyUp(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyUp
Timer1.Enabled = True
End Sub
Read the textbox with the event TextChanged like this:
If TextBox1.Text.Length >3 Then
Dim txt As String = Label1.Text + ", " + TextBox1.Text
If txt.Length = 6 Then txt = txt.Remove(0, 2)
Label1.Text = txt
'if you want to erase the text in TextBox1
TextBox1.SelectionStart = 0
TextBox1.SelectionLength = Label1.Text.Length
Try
End If
I use this code and it show the Barcodes in a label, you can replace the label to show in the textBox. Also, my Barcodes lenght always have 4 Alphanumeric characters. For you, Replace the If TextBox1.Text.Length >3 Then (3 to 8) to detect where a Barcode is readed.
hello i want to read text file line by line and set every lien in textbox eash time i click the button
this is my code and working fine. but i looking for easy way to read large text that has more thean 5 lines ?
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Static count As Integer
count = count + 1
Dim textfile As String = "c:\test.txt"
If IO.File.Exists(textfile) Then
Dim readLines() As String = IO.File.ReadAllLines(myFile)
If count = 1 Then
TextBox1.Text = readLines(0)
End If
If count = 2 Then
TextBox1.Text = readLines(1)
End If
If count = 3 Then
TextBox1.Text = readLines(2)
End If
If count = 4 Then
TextBox1.Text = readLines(3)
End If
If count = 5 Then
TextBox1.Text = readLines(4)
End If
If count = 6 Then
TextBox1.Text = readLines(5)
End If
End If
End Sub
I think you need to read the file just one time when you load your form (assuming a WinForms example here)
' Declare these two globally
Dim readLines() As String
Dim count As Integer = 0
Private void Form_Load(sender As Oject, e As EventArgs) Handles Base.Load
' In form load, read the file, just one time
Dim textfile As String = "c:\test.txt"
If IO.File.Exists(textfile) Then
readLines() As String = IO.File.ReadAllLines(myFile)
else
TextBox1.Text "File not found"
End If
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
' Check if you have a file and if you don't have reached the last line
if readLines IsNot Nothing AndAlso count < readLines.Length Then
TextBox1.Text = readLines(count)
count += 1
else
TextBox1.Text "End of file"
End If
End Sub
This reduces the amount of code you need to write:
TextBox1.Text = readLines(count - 1)