在输入android时显示字符？

Question

I need to see characters while I am typing characters in keyboard.But i want to get result from keyboard.

This is not used below this code :

@Override
public boolean dispatchKeyEvent(KeyEvent KEvent) 
{
    int keyaction = KEvent.getAction();

    if(keyaction == KeyEvent.ACTION_DOWN)
    {
        int keycode = KEvent.getKeyCode();
        int keyunicode = KEvent.getUnicodeChar(KEvent.getMetaState() );
        char character = (char) keyunicode;

        System.out.println("DEBUG MESSAGE KEY=" + character + " KEYCODE=" +  keycode);
    }


    return super.dispatchKeyEvent(KEvent);
}

Answer 1

Approach:Basic Idea is to get the unicode character. What it is and how to work with it, take a look on the links below. Following code shows three possibilities to get this unicode character from android.view.KeyEvent. Try what works for you.

android.view.KeyEvent event = ...you got the event

// first option
int unicode = event.getUnicodeChar();

// second option with meta-state
int unicode = event.getUnicodeChar(event.getMetaState());

// third option over the KeyCharacterMap
KeyCharacterMap map = event.getKeyCharacterMap();
int unicode = map.get(keyCode, event.getMetaState());

// once you have the unicode as integer you can do this to get the char
char unicodeChar = Character.toChars(unicode)[0];

UPDATE: // for older versions of android

Check this out in order to get the android.view.KeyCharacterMap:

KeyCharacterMap map = KeyCharacterMap.load(KeyCharacterMap.BUILT_IN_KEYBOARD);

Or just try to get this map somehow over the static methods from the mentioned class.

Good Programming! :-)

Some interesting links:

• http://developer.android.com/reference/android/view/KeyCharacterMap.html
• https://docs.oracle.com/javase/tutorial/i18n/text/unicode.html

Answer 2

In order to get the text while typing into an android.widget.EditText you have to use the android.text.TextWatcher . Please try following:

1. Create an android.text.TextWatcher instance
2. Use the android.text.TextWatcher.onTextChanged(CharSequence s, int start, int before, int count) method to get the text
3. Add the android.text.TextWatcher you created to the android.widget.EditText by android.widget.EditText.addTextchangedListener(..your text watcher);

Your initially question was to get the pressed key. Therefore use the passed java.lang.CharSequence and get the last char by:

char lastKey = s.charAt(s.length() - 1);

This should work. Before using this check if not null or if the length is actually not 0. So some checks before are always a good idea :-)

Hope this time you get your result!! Good Programming!

PS I tried this right now in a dummy app with following code and it does work :-)

    this.editText = (EditText) this.findViewById(R.id.edit_text);
    this.editText.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(final CharSequence s, final int start, final int before, final int count) {
            if (s != null && s.length() > 0) {
                final char lastKey = s.charAt(s.length()-1);
                Toast.makeText(MainActivity.this, String.valueOf(lastKey),
                        Toast.LENGTH_SHORT).show();
            }
        }

        @Override
        public void beforeTextChanged(final CharSequence s, final int start, final int count,
                final int after) {
            // TODO Auto-generated method stub
        }

        @Override
        public void afterTextChanged(final Editable s) {
            // TODO Auto-generated method stub
        }
    });