I'm trying to block my text boxes in order that they can only accept numbers. I was looking in the Internet and I found this code
Private Sub TextBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) HandlesTextBox1.TextChanged
If Not Char.IsNumber(e.KeyChar) And Not Char.IsControl(e.KeyChar) Then
e.Handled = True
End If
End Sub
The thing is that there is an error message displayed:
e.keychar is not a member of system.eventargs
I already imported the Imports System.EventArgs. Any idea how to fix this?
I believe the problem lies in the event you’re handling. It should probably not be TextChanged. e.KeyChar is usually in the EventArgs for KeyPress handlers. Try using something like TextBox1_KeyPress.
This should work:
Public Class Form1
Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs)
If e.KeyValue < 48 OrElse e.KeyValue > 57 Then _
e.SuppressKeyPress = True
End Sub
End Class
It needs to have (sender As Object, e As KeyPressEventArgs)
which e.KeyChar is a member of
Related
I want to go get keystrokes, and this code works. But when I add a button or textbox the code is not running. Can any one help me with this code:
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub Form1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles Me.KeyPress
If Asc(e.KeyChar) > 1 Then Label1.Text = e.KeyChar
End Sub
End Class
You need to set the Form's KeyPreview property to True, in which case the Form will raise those keyboard events
The following code eats the Enter key for a TextBox (with "MultiLine" set to True):
Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
If Asc(e.KeyChar) = 13 Then
e.Handled = True
End If
End Sub
The same code for a RichTextBox however doesn't work: The Enter key is not eaten:
Private Sub RichTextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles RichTextBox1.KeyPress
If Asc(e.KeyChar) = 13 Then
e.Handled = True
End If
End Sub
I don't see where I could have made a mistake.
Does anybody see where this behaviour might come from?
Got it.
I needs to be consumed in KeyDown. Unlike for TextBox:
Private Sub RichTextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles RichTextBox1.KeyDown
If e.KeyCode = Keys.Enter Then
e.Handled = True
End If
End Sub
I am wondering if anyone can help me to do the above question.
Basically what i have is a label which has had a randomly generated letter placed into it.
What I want to do is to show a msgbox (just to show that it works for now) when the same key in the label is pressed. I have tried two methods but none seem to work, could anyone point me in the right direction? It doesn't seem like it would be that hard, i am just new to coding.
Private Sub speedtyping_Keydown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Me.KeyPress
If (e.KeyChar = lblletter1.Text.ToString) Then
MsgBox("WORKS")
ElseIf (e.KeyChar = lblletter2.Text) Then
MsgBox("words")
End If
Many thanks!
In order to handle the form's KeyPress event, you need to set it's KeyPreview property. You can do that in the Form Designer or in the form's Load event handler as below.
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Me.KeyPreview = True
End Sub
Private Sub Form1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles Me.KeyPress
If e.KeyChar = lblletter1.Text(0) Then
MessageBox.Show("WORKS")
ElseIf e.KeyChar = lblletter2.Text(0) Then
MessageBox.Show("words")
End If
End Sub
End Class
Try this
Private Sub speedtyping_Keydown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Me.KeyPress
If (e.KeyChar.ToString = lblletter1.Text) Then
MsgBox("WORKS")
ElseIf (e.KeyChar.ToString = lblletter2.Text) Then
MsgBox("words")
End If
End Sub
Try this
Private Sub speedtyping_Keydown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Me.KeyPress
If (e.KeyChar.Trim() = lblletter1.Text.Trim()) Then
MsgBox("WORKS")
ElseIf (e.KeyChar.Trim() = lblletter2.Text.Trim()) Then
MsgBox("words")
End If
End Sub
I think this is possible, but I don't know... I want to check when the key A is pressed to move the player to the left, but for now just a messagebox.
Here is all the code I could find on the internet, it didn't work...
Private Sub TextBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyUp
If e.KeyCode = Keys.A Then
MsgBox("Left")
End If
End Sub
I am not asking how to do things when you enter stuff in a textbox, I'm asking how to run a event when you press a key.
Try this...
Private Sub TextBox1_KeyPress(sender As Object, e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
If Asc(e.KeyChar) = 97 Or Asc(e.KeyChar) = 65 Then
MsgBox("hello")
End If
End Sub
This should work. 97 is 'a' and 65 is 'A' in ASCII.
Try this
Private Sub TextBox1_KeyPress(sender As Object, e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
If e.KeyCode = Keys.A Then
MsgBox("Left")
End Sub
or
Private Sub textBox1_KeyDown(sender As Object, e As System.Windows.Forms.KeyEventArgs) _
Handles textBox1.KeyDown
If e.KeyCode = Keys.A Then
MsgBox("Left")
end if
End Sub
You probably want to set the form's KeyPreview property to true.
Doing this makes sure the form sees all key events even if one of
its child controls
Use the KeyEventArgs.KeyData property to see what key was pressed.
KeyCode , KeyData and KeyValue are members of
System.Windows.Forms.KeyEventArgs in the KeyUp and KeyDown events
only.
They actually simplified this from VB6.The new way with VB 2017 is...
Private Sub Textbox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles txtProblem.KeyPress
If e.KeyCode = "a" or e.KeyCode = "A" Then
MsgBox("Left")
End If
End Sub
So, I got one step in the right direction maybe it will help. I'm trying to give control of the paddle to the player in a game of pong and found if textbox1 is highlighted or "has focus" then these commands will execute and I can move the paddle around the screen. The problem is there is also a textbox filling up with letters in the corner of the screen as this happens I'm not sure how to get rid of just yet. Perhaps it will be useful though.
Private Sub
Textbox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
If Asc(e.KeyChar) = 97 Then 'a
Paddle.Location = New Point(Paddle.Location.X - 10, Paddle.Location.Y)
End If
If Asc(e.KeyChar) = 119 Then 'w
Paddle.Location = New Point(Paddle.Location.X, Paddle.Location.Y - 10)
End If
If Asc(e.KeyChar) = 100 Then 'd
Paddle.Location = New Point(Paddle.Location.X + 10, Paddle.Location.Y)
End If
If Asc(e.KeyChar) = 115 Then 's
Paddle.Location = New Point(Paddle.Location.X, Paddle.Location.Y + 10)
End If
End Sub
Also, you can use this command to give focus to the textbox from a different event
Public Sub ControlSetFocus(control As Control)
If Control.CanFocus Then
control.Focus()
End If
End Sub
This works for me
If e.KeyChar = Convert.ToChar("a") Then
MsgBox(Convert.ToChar("a") +"enter key pressed ")
End If
Also you can use numbers and uppercase in ""
I would like to know how i can validate a textbox to not allow any decimal values?
this solution i got from this link ( How to allow user to enter only numbers in a textbox in vb.net? )
Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
If (Microsoft.VisualBasic.Asc(e.KeyChar) < 48) _
Or (Microsoft.VisualBasic.Asc(e.KeyChar) > 57) Then
e.Handled = True
End If
If (Microsoft.VisualBasic.Asc(e.KeyChar) = 8) Then
e.Handled = False
End If
End Sub
You can use the KeyPress event and use the IsNumeric Function to trap the numeric keys.
Private Sub TextBox1_KeyPress(sender As System.Object, e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
If IsNumeric(e.KeyChar) Then
e.Handled = True
End If
End Sub
If you can, use a MaskedTextBox
Since handling the KeyPress can cause problem with delete/backspace/copy/paste/...