[RESOLVED] vb.net remove first char from text

[LiwisJames]

i'm make a textbox print another char with keydown event using this:


on keydown event:

if e.keycode = keys.A then
 My.Computer.Keyboard.SendKeys("B")
end if

i need know how i can remove the key that i press of end result see textbox show:

aBaBaB

but i only need B result on textbox

[.paul.]

Try…

if e.keycode = keys.A then
    e.Handled = True
    My.Computer.Keyboard.SendKeys("B")
end if

[jmcilhinney]

Don't use KeyDown in the first place. Use KeyPress and you can just replace the character:

Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
    If e.KeyChar = "A"c Then
        e.KeyChar = "B"c
    End If
End Sub

Note that KeyPressEventArgs.KeyChar was originally read-only but was made read/write some time ago. Unless you're targeting a really old .NET version, you should be fine.

Just note that, because this is working with characters and not keys, you will need to take case into account. You should have with keys too, i.e. you should have taken modifiers into account, but it's still different with KeyPress.

[jmcilhinney]

I just checked and it was .NET Framework 2.0 in which that KeyChar property was made read/write so you definitely should not have an issue with that.

[LiwisJames]

Try…

if e.keycode = keys.A then
    e.Handled = True
    My.Computer.Keyboard.SendKeys("B")
end if

nothing happens remains the same error.

[LiwisJames]

Don't use KeyDown in the first place. Use KeyPress and you can just replace the character:

Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
    If e.KeyChar = "A"c Then
        e.KeyChar = "B"c
    End If
End Sub

Note that KeyPressEventArgs.KeyChar was originally read-only but was made read/write some time ago. Unless you're targeting a really old .NET version, you should be fine.

Just note that, because this is working with characters and not keys, you will need to take case into account. You should have with keys too, i.e. you should have taken modifiers into account, but it's still different with KeyPress.

I chose keydown because it works when the key keeps pressing and sending input, how much keypress only sends the result when pressed several times, as in a game that asks to stay clicking a button several times to accomplish something.

[LiwisJames]

I just checked and it was .NET Framework 2.0 in which that KeyChar property was made read/write so you definitely should not have an issue with that.

framework 2 is very cool it is a hybrid between vb6 and vb.net many chose it.

[jmcilhinney]

framework 2 [...] is a hybrid between vb6 and vb.net

No it isn't. I don't know whether you're referring to the fact that default form instances were added to VB 2005 but that's a language thing, not a Framework thing.

[LiwisJames]

No it isn't. I don't know whether you're referring to the fact that default form instances were added to VB 2005 but that's a language thing, not a Framework thing.

yes I mean the design and likeness of code.

[jmcilhinney]

I chose keydown because it works when the key keeps pressing and sending input, how much keypress only sends the result when pressed several times, as in a game that asks to stay clicking a button several times to accomplish something.

That's complete rubbish. If you press and hold a key then you get multiple KeyDown and KeyPress events. You can see it for yourself if you bother to test. Try this code:

Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown
    Console.WriteLine($"KeyDown: {e.KeyCode} ({e.KeyData})")
End Sub
 
Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
    Console.WriteLine($"KeyPress: {e.KeyChar}")
End Sub
 
Private Sub TextBox1_KeyUp(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyUp
    Console.WriteLine($"KeyUp:  {e.KeyCode} ({e.KeyData})")
End Sub

Run that and watch the Output window in VS as you press, hold and release keys. Try using modifier keys as well and see the difference between KeyCode and KeyData.

[jmcilhinney]

yes I mean the design and likeness of code.

The only thing about VB 2005 that is more like VB6 than VB.NET 2003 is the fact that default form instances allow you to use a form without explicitly creating an object and passing a reference to it around. Not sure that that really qualifies as "design and likeness of code".

[LiwisJames]

That's complete rubbish. If you press and hold a key then you get multiple KeyDown and KeyPress events. You can see it for yourself if you bother to test. Try this code:

Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown
    Console.WriteLine($"KeyDown: {e.KeyCode} ({e.KeyData})")
End Sub
 
Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
    Console.WriteLine($"KeyPress: {e.KeyChar}")
End Sub
 
Private Sub TextBox1_KeyUp(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyUp
    Console.WriteLine($"KeyUp:  {e.KeyCode} ({e.KeyData})")
End Sub

Run that and watch the Output window in VS as you press, hold and release keys. Try using modifier keys as well and see the difference between KeyCode and KeyData.

Where from this shift ?

KeyPress: a
KeyUp: A (A)
KeyDown: ShiftKey (ShiftKey, Shift)
KeyDown: B (B, Shift)
KeyPress: B
KeyUp: B (B, Shift)
KeyUp: ShiftKey (ShiftKey)

[jmcilhinney]

Like I said, KeyDown and KeyUp are about keys on the keyboard while KeyPress is about characters. If you want an upper-case B character then you you need to depress and release both the Shift key and the B key, so to get a single KeyPress event you need two KeyDown events and two KeyUp events. Maybe make an effort on your own behalf and read the documentation for those events instead of asking someone else to explain it to you. That documentation exists for a reason.

[LiwisJames]

Like I said, KeyDown and KeyUp are about keys on the keyboard while KeyPress is about characters. If you want an upper-case B character then you you need to depress and release both the Shift key and the B key, so to get a single KeyPress event you need two KeyDown events and two KeyUp events. Maybe make an effort on your own behalf and read the documentation for those events instead of asking someone else to explain it to you. That documentation exists for a reason.

well I research about I have the concept of each, but I like to summarize the understanding of reading to be faster and learning and creation. but I read the Microsoft articles in 2016

thank u by u solution.

[LiwisJames]

Like I said, KeyDown and KeyUp are about keys on the keyboard while KeyPress is about characters. If you want an upper-case B character then you you need to depress and release both the Shift key and the B key, so to get a single KeyPress event you need two KeyDown events and two KeyUp events. Maybe make an effort on your own behalf and read the documentation for those events instead of asking someone else to explain it to you. That documentation exists for a reason.

worked friend worked and even more it does faster and better the concepts are widespread and keypress presents more positive result.