Android keyguard之上如何显示Toast

ENV : Android M 6.0.1

锁屏之上应该如何显示Toast呢？ 看下面的实现：

public class KeyguardToast {

    public static Toast makeText(Context context, CharSequence text, int duration) {
        Toast toast = Toast.makeText(context, text, duration);
        toast.getWindowParams().type = WindowManager.LayoutParams.TYPE_STATUS_BAR_PANEL;
        toast.getWindowParams().privateFlags |= WindowManager.LayoutParams.PRIVATE_FLAG_SHOW_FOR_ALL_USERS;
        toast.getWindowParams().flags |= WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED;

        // set offset position
        toast.setGravity(Gravity.CENTER, 0, 400);
        return toast;
    }
}

锁屏之上如何显示Dialog？看下面的实现：

public class SystemUIDialog extends AlertDialog {

    private final Context mContext;

    public SystemUIDialog(Context context) {
        super(context, R.style.Theme_SystemUI_Dialog);
        mContext = context;

        getWindow().setType(WindowManager.LayoutParams.TYPE_STATUS_BAR_PANEL);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM
                | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
        WindowManager.LayoutParams attrs = getWindow().getAttributes();
        attrs.setTitle(getClass().getSimpleName());
        getWindow().setAttributes(attrs);
    }

    public void setShowForAllUsers(boolean show) {
        if (show) {
            getWindow().getAttributes().privateFlags |=
                    WindowManager.LayoutParams.PRIVATE_FLAG_SHOW_FOR_ALL_USERS;
        } else {
            getWindow().getAttributes().privateFlags &=
                    ~WindowManager.LayoutParams.PRIVATE_FLAG_SHOW_FOR_ALL_USERS;
        }
    }

    public void setMessage(int resId) {
        setMessage(mContext.getString(resId));
    }

    public void setPositiveButton(int resId, OnClickListener onClick) {
        setButton(BUTTON_POSITIVE, mContext.getString(resId), onClick);
    }

    public void setNegativeButton(int resId, OnClickListener onClick) {
        setButton(BUTTON_NEGATIVE, mContext.getString(resId), onClick);
    }
}