如何在自定义android键盘中定义上下箭头

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.setInputMethod(getPackageName() + ".CustomKeyboard");

InputConnection ic = getCurrentInputConnection();
ic.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DPAD_UP));
ic.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_DPAD_UP));

<activity
    android:name=".YourActivity"
    android:windowSoftInputMode="stateAlwaysHidden"
    android:configChanges="orientation|keyboardHidden">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
    <meta-data
        android:name="android.view.inputmethod"
        android:resource="@xml/keyboard" />
</activity>