I'm writing a program that kids can use to code from within my application instead of a console-based approach
So I have a lesson that teaches them about message boxes, they are given a sample line of code and what it creates and are told to create their own by entering code into a textbox to create their own that says "Hey Dude!", the problem is, I'm having trouble getting the system to check if what they entered was correct or not... eg:
Private Sub btnShowMsgBox_Click(sender As Object, e As EventArgs) Handles btnShowMsgBox.Click
If txtUserInput.Text = MessageBox.Show("I can code!") Then
MessageBox.Show("I can code!")
Else
MessageBox.Show("That's not quite right, try again!")
End If
I've tried adding " " around the relevent code on the first line of the if statement but no joy, as well as trying a variable approach
So basically the problem is the program is getting confused and doesn't understand why I'm checking to see if code for a message box is present, the syntax of the messagebox code doesn't fit well either
Does anyone have any suggestions as to how I would get this working? The logic is so straightforward but it's driving me nuts!
Thanks a million in advance
I believe you want the code to look more like...
Private Sub btnShowMsgBox_Click(sender As Object, e As EventArgs) Handles btnShowMsgBox.Click
If txtUserInput.Text = "MessageBox.Show(""I can code!"")" Then
MessageBox.Show("I can code!")
Else
MessageBox.Show("That's not quite right, try again!")
End If
The double quotes will return as single quotes within the string between the single quotes.
Related
I'm trying to format two specific text boxes to show up as Sq. ft. (txt.Squareft.Text) and US currency (txtTotalprice.Text) after a calculation has been made in Visual Studio 2019 as a Windows Form Application and using visual basic code. I am using .NET framework v4.7.2 and utilizing Windows 10. The way it runs now, the numbers that show up in the textboxes are just numbers without the added Sq. ft. at the end and no currency formatting. I will also add that I am very new to VB and programming in general. Any help or suggestions?
Option Explicit On
Option Infer Off
Public Class Form1
Private Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click
'Variables
Dim decTotalprice As Decimal
Dim decLength As Decimal
Dim decWidth As Decimal
Dim decPrice As Decimal
Dim decSquareft As Decimal
Decimal.TryParse(txtLength.Text, decLength)
Decimal.TryParse(txtWidth.Text, decWidth)
Decimal.TryParse(txtPrice.Text, decPrice)
Decimal.TryParse(txtSquareft.Text, decSquareft)
txtTotalprice.Text = decTotalprice.ToString("C2")
txtSquareft.Text = decSquareft.ToString("N2") & " Sq. ft."
' Calculate the square feet and total price
txtSquareft.Text = txtLength.Text * txtWidth.Text
txtTotalprice.Text = txtPrice.Text * txtSquareft.Text
End Sub
Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click
' Clears all the text fields with button click
txtLength.Clear()
txtWidth.Clear()
txtPrice.Clear()
txtSquareft.Clear()
txtTotalprice.Clear()
End Sub
Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
' Exits the form
Me.Close()
End Sub
End Class
There are two primary issues here and I feel like I bring them up at least ten times a day. Firstly, you are trying to write code without knowing what that code has to do. You've considered the end result but not the steps to get there. If you had done that then it would be obvious that your code doesn't what it's supposed to. Secondly, you clearly haven't debugged your code, which is the first thing anyone should do when they don't get the expected result. That would also let you see that your code doesn't make sense IF you considered what each line is supposed to be doing as it does it.
If this was a manual task, you would get the input from the user, perform the calculation, then display the result. Is that what you're doing here? No, it is not. First you get the user input. That's a start, but you're doing it wrong. As it stands, you would end with zero for any invalid input but you're just ignoring that. The next thing you do is display the formatted output that you haven't even calculated yet. If you had debugged, you'd have seen that both decTotalprice and decSquareft are zero at that point. You finally do the calculations, but with the raw text input instead of the numbers you already parsed, and then you display the results unformatted. You've even got a comment in your code that says that you're doing the calculation AFTER you've displayed the formatted output.
Stop writing code and think about what the required steps are to get to your desired result. Parse the user input, perform the calculations with the numeric data and not the unparsed text, then display those results with formatting. Once you have a clear idea of what you have to do AND tested that manually, then you can write code to implement that algorithm, rather than some vague idea in your head that involves a final result and little else.
You're certainly not the only person who makes these mistakes but they are elementary mistakes. They happen partly because of bad teaching in some cases, but they also happen because everyone wants to jump into the part that is sexy and fun, i.e. writing the code, but they don't want to do the harder but just as important part of considering what the code actually has to do. When they don't get the expected result, they throw their hands up without ever really having tried to fix it. If you haven't tried to understand what the code has to do, you can't have tried to make it do that.
I have declared a Sub that is meant to trigger when the listbox 'lstStudents' is double-clicked. However, it does not trigger when this happened. There can't be an error in the code itself as it is auto-generated. Why does the code not function as expected? The code is below:
Private Sub lstStudents_DoubleClick(sender As Object, e As EventArgs) Handles lstStudents.DoubleClick
Msgbox("test")
End Sub
The message box is only present for testing purposes.
Could You try to delete that previous "lstStudents" and add new one then apply the "ListBox1_DoubleClick" on it again to make sure it works.
Otherwise let us know what is going there because I think your code is normally and it should be working 100%.
I'm working on visual studio 2015 and I'm working on a classic subscribing form.
I want to generate error labels when the user type wrong password, the wrong pseudo, etc. But I can work on it myself.
But when I write those error labels and set their visible at false in "Dev mode", I have to juxtapose those labels if I want my labels at the same place, and it's not what I want when I have many errors to manage on one textBox for example.
Is there a solution to gererate those labels, without write them before playing with hide() or show() ?
Here is the screenshot in order to illustrate my problem.
It's not really a problem itself, but It's not practical when I'm develop many errors.
Sorry for my english, I hope you understood my problem, I can give you more details =)
Have a nice day full of code !
Here the button code:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If TextBox1.Text <> "Password" Then
Label2.Text = "Your answer is wrong"
End If
End Sub
This is what it looks like:
I am coding a terminal in VB.net, And when I type in 'help' and press enter, Nothing happens. It is supposed to show 'This is the only command. :P'.
I appear to not be more specific so let me explain what happened.
I put in the code below, I executed the application and then I typed in 'help' and then I hit the enter key then nothing happened at ALL.
Here is the entire code:
Private Sub RichTextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles RichTextBox1.KeyPress
Dim lines = RichTextBox1.Lines
Dim num = lines
Dim textlength = RichTextBox1.TextLength
If Asc(e.KeyChar) = 13 Then
If num.Last.ToString() = "help" Then
RichTextBox1.AppendText("This is the only command. :P\r\n")
End If
End If
End Sub
Please help!
So, having attached a debugger to your code, it was instantly obvious what the problem is... When you get to the comparison, lines.Last() is an empty string.
There are a number of ways to get the 2nd to last line. I prefer LINQ, so here's your code tidied up, using a case and culture-insensitive string comparison (so you can type Help too)...
Private Sub RichTextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles RichTextBox1.KeyPress
If Asc(e.KeyChar) = 13 Then
If String.Equals(RichTextBox1.Lines.Reverse.Skip(1).First(),
"help",
StringComparison.InvariantCultureIgnoreCase) Then
RichTextBox1.AppendText(String.Format("This is the only command. :P{0}", Environment.NewLine))
End If
End If
End Sub
I've also used Environment.NewLine to make your code more portable, and String.Format() to combine the strings in a way that doesn't eat memory for no reason. It's overkill for this example but it shows how it should be done.
It's worth noting that using a debugger is a crucial skill for any developer (well, ok, there is an alternative which is extensive logging, but you need to know both). You will need this skill to solve any number of problems.
In case you're not familiar with the concept, debugging is like pausing your program and letting you examine what's going on, then run a single command at a time to see what the program is doing.
This isn't really an answer, but I noticed that you are writing your code to create a new line incorrectly
You did this:
RichTextBox1.AppendText("This is the only command. :P\r\n")
While it should be something like this:
RichTextBox1.AppendText("This is the only command. :P" & vbCrLf)
By trying your code and removing the
If num.Last.ToString() = "help" Then
End If
And putting this line of code
If Asc(e.KeyChar) = 13 Then
RichTextBox1.AppendText(Environment.NewLine & "This text will appear on the next line.")
End If
It works fine.
Hope this helps.
I use the LostFocus Event in vb.net to check the validity of a field for the name.
After this field a have another one which is the for the password validity, and i'm handilg the same event in order to check the password.
My problem comes when i run the (name) lost focus, runs the code inside the sub and after that automatically goes to the password_lostfocus which brings me alot of troubles.
That happens even i use the error provider which works fine and bring to me the error with the red flashing.After that i put the command (name_textbox.focus), which logically has to bring the control in the name_textbox.. But NO.. the control goes to the Password_textbox sub automatically.
Please see my sub
Private Sub UsernameTextBox_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles UsernameTextBox.LostFocus
Select Case DB_Access.IfExistUser(UsernameTextBox.Text, sender, e)
Case True
PasswordTextBox.Focus()
Case False
ErrorProvider1.SetError(UsernameTextBox, "Ο χρήστης ΔΕΝ υπάρχει παρακαλώ καλέστε τον Administrator")
Beep()
UsernameTextBox.Text = ""
UsernameTextBox.Focus()
End Select
End Sub
Please if anyone have seen this issue and face it, assist me.
Excuse me for some Greek characters they are meaningless, they are comments
Well finally i found that.
In order to handle the Login Form as it give it from visual studio 2010 you need to do it in only one sub (Lost Focus) and that is only the password_LostFocus.
I believe the particular form is meant to be like that.
Any way i solve the issue and if anybody needs assistance on that just "asc a question"