Dynamically moving a control for each character in a Textbox - vb.net

Basically I'm trying to make a CheckBox move to the right using:
chk_ShowPassword.Location = New Point(X, Y)
Now the way I'm trying to do this is by checking for each character in the textbox and depending on the amount of characters there is, the checkbox will move to the right. I'm using:
For Each chr As Char In tb1.Text
chk_ShowPassword.Location = New Point(++85, 95)
Next
I need help with 2 things, I'm not sure why but it seems to be not moving to the right. It's meant to be moving to the right by 85 for each character. The other thing is that is 85 a good increment method for each character, is it too much, too little,
Can someone help me with this. Please if it's not clear you can ask me where to expand on and I'll do my best.

I think its important to save the starting point and do the movements from there. "Orgchk_ShowPasswordLocation"
So you can always go back to the starting point.
Do a count for the chars and then use "Orgchk_ShowPasswordLocation.X + Count * 10"
Then it will move forward or backwards if you add or delete chars in the text box.
Dim Orgchk_ShowPasswordLocation As Point
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Orgchk_ShowPasswordLocation = chk_ShowPassword.Location
End Sub
Dim cby As Integer
Dim cbx As Integer
Dim Count As Integer
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles tb1.TextChanged
cby = chk_ShowPassword.Location.Y
cbx = chk_ShowPassword.Location.X
Count = Nothing
For Each chr As Char In tb1.Text
Count = Count + 1
Next
cbx = Orgchk_ShowPasswordLocation.X + Count * 10
chk_ShowPassword.Location = New Point(cbx, cby)
End Sub

Related

Calculate cost of several items with tax and a discount

Can anyone help with this school task I have
The task is to ask the user for items and the cost of the items until they chose to stop. Then combine all the costs and take 20% VAT and 10% off from 2 randomly selected items.
Here is the code I have so far (I have 2 buttons and a listbox)
Public Class Form1
Dim CurrentA As Integer
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim Items(CurrentA) As String
Dim Coins(CurrentA) As Single
Dim Stay As String
CurrentA = 0
Do Until CurrentA = 20
Items(CurrentA) = InputBox("Please Enter The Item")
Coins(CurrentA) = InputBox("Please Enter The Cost Of The Item")
Stay = InputBox("Type Yes If More Items or Type No if no More")
Stay = Stay.ToLower
If Stay = "yes" Then
End If
If Stay = "no" Then
Exit Do
End If
ListBox1.Items.Add(Items(CurrentA) & " " & Coins(CurrentA))
CurrentA += 1
Loop
End Sub
End Class
First, a few comments on the code you presented.
Dim CurrentA As Integer
'An Integers default value is zero, I don't see why this is a class level variable
'always declare variables with as narrow a scope as possible
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Dim Items(CurrentA) As String 'Declares an Array of Type String with an Upper Bound of 0
'Upper Bound is the highest index in the array
'Arrays start with index 0
'So your array will have 1 element at index 0
Dim Coins(CurrentA) As Single
Dim Stay As String
CurrentA = 0 'unnecessary because the default of CurrentA is already 0, but OK for clarity because it could have been changed elsewhere
'This is behaving like a console application with the code repeating in a loop.
'In Windows Forms it would be more likely to do this in a button click event (btnAddItem)
Do Until CurrentA = 20
'On the first iteration CurrentA = 0
'On the second iteration CurrentA = 1 - this exceeds the size of your array
'and will cause an index out of range error
Items(CurrentA) = InputBox("Please Enter The Item")
'With Option Strict on you must change the input to a Single
Coins(CurrentA) = CSng(InputBox("Please Enter The Cost Of The Item"))
Stay = InputBox("Type Yes If More Items or Type No if no More")
Stay = Stay.ToLower 'Good! The user might no follow directions exactly
If Stay = "yes" Then
'This is kind of silly because it does nothing
End If
'Lets say I say no on the first iteration
'This avoids the index out of range error but
'nothing is added to the list because you Exit the loop
'before adding the item to the ListBox
If Stay = "no" Then
Exit Do
End If
ListBox2.Items.Add(Items(CurrentA) & " " & Coins(CurrentA))
CurrentA += 1
Loop
End Sub
We could use arrays but not knowing how many items will be added means either making the array bigger than needed or using Redim Preserve on every addition. A much better choice is a List(Of T). They work a bit like arrays but we can just add items without the ReDim stuff.
Private lstCost As New List(Of Single)
Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
'Pretend this button is called btnAdd, and you have 2 test boxes
lstCost.Add(CSng(TextBox2.Text))
'The $ introduces an interpolated string. It is a step up form String.Format
ListBox2.Items.Add($"{TextBox1.Text} - {CSng(TextBox2.Text):C}") 'The C stands for currency
TextBox1.Clear()
TextBox2.Clear()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
'Pretend this button is called btnTotal
'Dim total As Single = (From cost In lstCost
' Select cost).Sum
Dim total As Single = lstCost.Sum
Label1.Text = total.ToString("C") 'C for Currency
End Sub

Alternative Process

I have 2 buttons and a DataGridView with 2 Columns (0 & 1).
The 1st button transfers a randomized cell from the Column(1) to a TextBox. Then, it stores that Cell in variable (a), plus the cell that opposites it in variable (b).
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Dim rnd As New Random
Dim x As Integer = rnd.Next(0, Form1.DataGridView1.Rows.Count)
Dim y As Integer = 1
Dim a As String = Form1.DataGridView1.Rows(x).Cells(y).Value
Dim b As String = Form1.DataGridView1.Rows(x).Cells(y - 1).Value
TextBox3.Text = a
End Sub
The 2nd button, however, is supposed to compare if another TextBox's text has the same string variable (b) has as Strings. Now, if so, then it has to display a certain message and so on...
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
If TextBox4.Text = b Then '<<< ISSUE HERE!
MsgBox("Correct! ^_^")
ElseIf TextBox4.Text = "" Then
MsgBox("You have to enter something first! O_o")
Else
MsgBox("Wrong! >,<")
End If
End Sub
The problem is that the variable (b) is surely not shared across the two "private" subs. And so, there is NOTHING to compare to in the 2nd button's sub! I presume that the solution here is to split the "randomization process" into a separate function, then execute it directly when the 1st button gets activated. Furthermore, that function's variables have to be SHARED somehow, and I certainly don't know how!
Thanks for Mr. Olivier, the code has been improved significantly! Yet, I still encounter a "wrong" comparison issue, somehow!
Dim RND As New Random
Dim x As Integer
Private Function GetCell(ByVal rowIndex As Integer, ByVal cellIndex As Integer) As String
Return Form1.DataGridView1.Rows(rowIndex).Cells(cellIndex).Value
End Function
Private Sub btnRoll_Click(sender As Object, e As EventArgs) Handles btnRoll.Click
x = RND.Next(0, Form1.DataGridView1.Rows.Count)
tbxRoll.Text = GetCell(x, 1)
End Sub
Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
If tbxSubmit.Text = GetCell(x, 0) Then
MsgBox("Correct! ^_^")
ElseIf tbxSubmit.Text = "" Then
MsgBox("You have to enter something first! O_o")
Else
MsgBox("Wrong! >,<")
End If
End Sub</code>
Well, unbelievably, I read a guide about "comparison operations" in VB.net and tried out the first yet the most primal method to compare equality - which was to use .Equals() command - and worked like a charm! Thank God, everything works just fine now. ^_^
If tbxSubmit.Text.Equals(GetCell(x, 0)) Then
Alright now... This is going to sound weird! But, following Mr. Olivier's advise to investigate "debug" the code, I rapped the string I'm trying to compare with brackets and realized that it's been outputted after a break-line space! So, I used the following function to remove the "white-space" from both of the comparison strings! And it bloody worked! This time for sure, though. ^_^
Function RemoveWhitespace(fullString As String) As String
Return New String(fullString.Where(Function(x) Not Char.IsWhiteSpace(x)).ToArray())
End Function
If RemoveWhitespace(tbxSubmit.Text) = RemoveWhitespace(GetCell(x, 0)) Then
Turn the local variables into class fields.
Dim rnd As New Random
Dim x As Integer
Dim y As Integer
Dim a As String
Dim b As String
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
x = rnd.Next(0, Form1.DataGridView1.Rows.Count)
y = 1
a = Form1.DataGridView1.Rows(x).Cells(y).Value
b = Form1.DataGridView1.Rows(x).Cells(y - 1).Value
TextBox3.Text = a
End Sub
These fields can now be accessed from every Sub, Function and Property.
Of course Button3_Click must be called before Button2_Click because the fields are initialized in the first method. If this is not the case then you should consider another approach.
Create a function for the Cell access
Private Function GetCell(ByVal rowIndex As Integer, ByVal cellIndex As Integer) _
As String
Return Form1.DataGridView1.Rows(rowIndex).Cells(cellIndex).Value
End Function
And then compare
If TextBox4.Text = GetCell(x, y - 1) Then
...
And don't store the values in a and b anymore. If y is always 1 then use the numbers directly.
If TextBox4.Text = GetCell(x, 0) Then
...
One more thing: give speaking names to your buttons in the properties grid before creating the Click event handlers (like e.g. btnRandomize). Then you will get speaking names for those routines as well (e.g. btnRandomize_Click).
See:
- VB.NET Class Examples
- Visual Basic .NET/Classes: Fields

Getting upperbound and lowerbound from a textbox

I'm trying to figure out the code for a project but I don't completely understand it. The objective is to write a program that generates a set of 10 random numbers and stores it in an array (the 10 numbers display in the textbox correctly). It should have a button that will compute the minimum, maximum and average of the array. I cant seem to get the max and min values of it from a textbox. I know people don't post the answers and I'm not looking for that but if someone could tell my why what I'm doing for the max/min is wrong or point my in the right direction I would appreciate it. Thank you!
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim randomArray As New Random()
Dim randomNumber As Integer
For i = 1 To 10
randomNumber = randomArray.Next(1, 101)
displaynumbersTextBox1.AppendText(randomNumber & " ")
displaynumbersTextBox1.Text = Convert.ToString(randomNumber)
Next
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim randomArray As New Random()
Dim randomNumber As Integer
For i = 1 To 10
randomNumber = randomArray.Next(1, 101)
displaynumbersTextBox1.AppendText(randomNumber & " ")
Next
Dim min As Integer
min = displaynumbersTextBox1.Text.GetLowerBound()
displayminTextBox2.Text = min
End Sub
For starters, I see this code in Button1:
TextBox1.AppendText(randomNumber & " ")
TextBox1.Text = Convert.ToString(randomNumber)
The 2nd line negates the first. Just remove it. Instead, clear the textbox at the beginning of the button click handler.
Next, in button 2 the code goes through and re-creates a new set of random numbers, instead of using the set created from the first button. What is more, at no point are the numbers ever stored in an array. You need an array declared outside of either button, in in the code for Button1 set the elements of the array, so you can use those numbers again in Button2 more easily.

Case Statement not working with String Literals

Hi all I am trying to learn VB and am having trouble with some code I am using. I would like my program to output a specific number based on if a check box is checked using case statements but my code is not working.
Public Class frmBTPW
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles btncalc.Click
Dim dblhdr As Double
Dim dblfdr As Double
Dim dbltdr As Double
dblhdr = 24
dblfdr = 35
dbltdr = 50
Select Case "Power Wash Rental"
Case "Half Day Rental"
If chkhd.Checked = True Then
txtrc.Text = "poop"
End If
Case "Full Day Rental"
If chkFD.Checked = True Then
txtrc.Text = dblfdr
End If
End Select
End Sub
Private Function Button1_Click() As CheckBox
Throw New NotImplementedException
End Function
End Class
Help would be greatly appreciated.My code isn't outputting anything in the text-box.
Beyond case statements, respectfully I think you should read up on the distinction between a literal value and a variable. "Power Wash Rental" is nothing more than a series of characters, AKA a string: (In this case "P" followed by "o" etc.) Likewise, "Half Day Rental" is a series of characters, "H" followed by "a" etc.)
"Power Wash Rental" is a literal string. So is ""Half Day Rental" and of course they will never match.
Whereas:
Dim A as string
A = TextBox1.text
Now, A is a variable. It is a string which contains whatever series of characters (text) is typed into the textbox.
This is a simple way to do it.
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
chkhd.tag = 24 ' store values in the check boxes
chkfd.tag = 35 ' using the tag property
chktd.tag = 50 ' and later add up the values
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles btncalc.Click
dim total as double = 0
total += IF(chkhd.checked, cdbl(chkhd.tag), 0)
total += IF(chkfd.checked, cdbl(chkfd.tag), 0)
total += IF(chktd.checked, cdbl(chktd.tag), 0)
msgbox(total)
End Sub
However, I think you might want radio buttons instead of checkboxes.
Checkboxes can all be checked. Radio buttons can only have one at a time.
This solution allows you to keep your price with the checkbox -- you could do this in the form designer instead of form load.
I would recommend reading up on Case Statements. Currently you will never get anywhere as your using a string to what, nothing. You also do not need a case for this... Also if the first condition is true and the last one is as well, the last one win's for setting the text, didn't know if you had this there for a reason or not?
If chkhd.Checked = True Then
txtrc.Text = "poop"
End If
If chkFD.Checked = True Then
txtrc.Text = dblfdr
End If
As others have stated your Case statement isn't working because you are using string literals to compare "Power Wash Rental" to "Half Day Rental" which will always be false. Plutonix was also correct in saying that a ComboBox for the rental duration should be used. The only reason not to be is if you were calculating cumulative rental days/amounts; however in that situation you should be using some sort of NumericUpDown for your multiplier against a time duration.
Here is an example that should help you get started. You could make the structure into a type of keyed collection or make it a wrapper class for a dictionary object which would make be easier to use in code. The following may not be exactly plug-and-play with your project, however it should help give you some ideas on how to handle the situation.
Option Strict On
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Me.ComboBox1.Items.AddRange({PowerWashRentals.halfDayText, PowerWashRentals.FullDayText, PowerWashRentals.TwoDayText})
AddHandler ComboBox1.SelectedValueChanged, AddressOf Me.ComboBox1_SelectedChanged
End Sub
Private Sub ComboBox1_SelectedChanged(sender As Object, e As EventArgs)
Dim cBox As ComboBox = DirectCast(sender, ComboBox)
Select Case cBox.SelectedItem.ToString
Case PowerWashRentals.halfDayText
Label1.Text = PowerWashRentals.HalfDayPrice.ToString
Case PowerWashRentals.FullDayText
Label1.Text = PowerWashRentals.FullDayPrice.ToString
Case PowerWashRentals.TwoDayText
Label1.Text = PowerWashRentals.TwoDayPrice.ToString
End Select
End Sub
End Class
Public Structure PowerWashRentals
Public Const HalfDayPrice As Double = 24
Public Const FullDayPrice As Double = 35
Public Const TwoDayPrice As Double = 50
Public Const halfDayText As String = "Half Day Rental"
Public Const FullDayText As String = "Full Day Rental"
Public Const TwoDayText As String = "Two Day Rental"
End Structure

Getting row number in a DataGridView

How do you get row number DataGridView cell? Specifically, if a user has selected a single cell, how can you get that row number? It needs to access a particular cell based on what the user has selected.
I know that the RemoveAt method can be used to remove at the Focus, but you cannot get the row number at focus apparently?
Thanks for the help!
You can simply use RowIndex on the current cell:
var row = dataGridView1.CurrentCell.RowIndex;
this one works fine .
Private Sub DataGridView1_RowPrePaint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewRowPrePaintEventArgs) Handles DataGridView1.RowPrePaint
If e.RowIndex >= 0 Then
Me.DataGridView1.Rows(e.RowIndex).Cells(0).Value = e.RowIndex + 1
End If
End Sub
It is nearly the same but you may also use this solution:
var row = dataGridView1.CurrentRow.Index
Another way if you need to track user interaction with a DataGridView:
In my case there is extra processing in some generic functions that use the Me.I_SelCol and Me.I_SelRow column and row coordinates, but I haven't shown that because it's not relevant to the OP.
Best regards,
Rob
Private Sub I_DataGridView_CurrentCellChanged(sender As Object, e As EventArgs) Handles I_DataGridView.CurrentCellChanged
If Me.I_DataGridView.CurrentCellAddress.X < 0 Or Me.I_DataGridView.CurrentCellAddress.Y < 0 Then Exit Sub
' The Windows Me.I_DataGridView object will have already deselected the current cell and selected the
' new cell as per user navigation using mouse or cursor keys. We just need to store the current
' co-ordinates for the currently selected cell.
Me.I_SelCol = Me.I_DataGridView.CurrentCellAddress.X
Me.I_SelRow = Me.I_DataGridView.CurrentCellAddress.Y
Exit Sub
If you in event procedure of datagridview you will found "e As DataGridViewCellEventArgs" you can get row number with e.RowIndex and column number with e.ColumnIndex
Private Sub myDGV_CellLeave(sender As Object, e As DataGridViewCellEventArgs) Handles myDGV.CellLeave
Dim myRow As Integer = e.RowIndex
End Sub
And if you in normal procedure you can get row number like this:
Private Sub btnGetRow_Click(sender As Object, e As EventArgs) Handles btnGetRow.Click
dim myRow1 as Integer = 0
dim myRow2 as Integer = 0
myRow1 = myDGV.CurrentCell.RowIndex
myRow2 = myDGV.CurrentRow.Index
End Sub