android屏蔽返回键

import android.view.KeyEvent;

public boolean onKeyDown(int kCode, KeyEvent kEvent) {    switch (kCode) {    case KeyEvent.KEYCODE_DPAD_LEFT: {        return true;    }    case KeyEvent.KEYCODE_DPAD_UP: {        return true;    }    case KeyEvent.KEYCODE_DPAD_RIGHT: {        return true;    }    case KeyEvent.KEYCODE_DPAD_DOWN: {        return true;    }    case KeyEvent.KEYCODE_DPAD_CENTER: {        return true;    }    case KeyEvent.KEYCODE_BACK: {        return false;    }    }    return super.onKeyDown(kCode, kEvent);}