How to send key event to an edit text

Question

For example, send a backspace key to the edit text control to remove a character or send a char code like 112 to append a character in the edittext control programmatically.

Answer 1

Your question is not all that clear, but I think you want to modify/append text to a TextView when certain buttons are pressed. If so, you want a combination of some of the existing answers.

@Override
public void onCreate(Bundle savedInstanceState) {
    ...
    (TextView) textView = (TextView) findViewById(R.id.myTextView);
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
    switch(keyCode) {
    case KeyEvent.KEYCODE_BACK:
        // user pressed the "BACK" key.  Append "_back" to the text
        textView.append("_back");
        return true;
    case KeyEvent.KEYCODE_DEL:
        // user pressed the "BACKSPACE" key.  Append "_del" to the text
        textView.append("_del");
        return true;
    default:
        return super.onKeyDown(keyCode, event);
    }
}

Whether to return true for each case you have handled (as above) or to always return super.onKeyDown(keyCode, event); after your switch statement will depend on your exact requirements. Check the documentation for the behaviour of onKeyDown

If, instead of appending text in each case you want to delete a character, or move the cursor, you could do that in each case statement. Have a look at the TextView documentation for the different methods you can call. Also look at the KeyEvent documentation for a list of the keys you can check for.