Manipulating Keyboard Input

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4.00/5 (1 vote)

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Hello Experts,

How can i manipulate the input inside a edit box,
let's suppose,

when a edit box has a focus, and we press a key (say letter 'A'), i want it to be displayed as letter 'B' instead of 'A',

which is is the best place to manipulate this, among all different keyboard events, i tried it several places but no success.

KeyDown,
KeyPress
KeyUp
PreviewKeyDown

please suggest.

regards Prateek.

Posted 23-Mar-11 23:38pm

Katiyar S.

Updated 24-Mar-11 18:16pm

Sergey Alexandrovich Kryukov

v2

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Sergey Alexandrovich Kryukov 24-Mar-11 13:11pm

OK, you got some Answers, but I'm not sure they are for you, because... Tag your Question properly. WPF, WinForms? - what?
--SA

Katiyar S. 24-Mar-11 23:32pm

i want to create a control, so it can be used at both (Web form, Windows form) places.

Sergey Alexandrovich Kryukov 25-Mar-11 0:15am

Why didn't you tag your question? Still don't want answers? People look at the Question list first, so you need tags.
--SA

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Brijesh Kr · Answer 1 · 2011-03-24T18:41:00

Solution 5

Hey the best event is KeyDown, at handler just cancel KeyEventArgs,

C#

private void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            Keys k = (Keys)sender;
            if(k.GetType = Keys.A)
            e.Handled = false; // to check it to fulfill
            
            // Do as your wish
        }

Hope it would help you..

Posted 24-Mar-11 18:41pm

Brijesh Kr

Comments

Sona s 25-Mar-11 9:17am

Its a Good 1 tips..

Sergey Alexandrovich Kryukov · Answer 2 · 2011-03-24T18:23:00

Solution 4

This sample works, tested:

C#

MyTextBox.KeyPress += (sender, eventArgs) => {
    if (eventArgs.KeyChar == 'A')
        eventArgs.KeyChar = 'B';
};

—SA

Posted 24-Mar-11 18:23pm

Sergey Alexandrovich Kryukov

Bosah Chude · Answer 3 · 2011-03-24T03:34:00

Solution 3

C#

private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyData.ToString().Equals("A"))
    {
        textBox1.Text += "B";
    }
}

Posted 24-Mar-11 3:34am

Bosah Chude

Comments

Sergey Alexandrovich Kryukov 25-Mar-11 0:18am

This will not do the trick because you cannot assume insertion point is at the end.
--SA

Nick Reshetinsky · Answer 4 · 2011-03-24T03:05:00

Solution 2

KeyPress would do it has additional event arguments so you can better analyza keyboard events

Posted 24-Mar-11 3:05am

Nick Reshetinsky

Comments

Sergey Alexandrovich Kryukov 25-Mar-11 0:24am

This is the only variant which works, I only put code sample and test it.

#realJSOP · Answer 5 · 2011-03-23T23:43:00

Solution 1

Handle the TextChanged event for the TextBox.

Posted 23-Mar-11 23:43pm

#realJSOP

Comments

avigodse 24-Mar-11 11:08am

Hi John, i wonder that TextChanged event will be raised after TextBox's value updates. We need to get it and change it before its assigned to TextBox.

Sergey Alexandrovich Kryukov 25-Mar-11 0:25am

The problem is that TextChanged has no parameters.
I found a solution using KeyPress, see my Answer.
(I did not vote.)
--SA