菜单打开时覆盖 BackButton

Question

我想要实现的是，当用户在MENU可见时单击后退按钮时，menuActual和MENU的状态从可见变为不可见。如果MENU未打开且用户单击返回，则会Toast显示"Press again to Exit"，如果您在 2 秒内单击返回，应用程序将关闭。我拥有的代码：@Override    public void finish() {    if (MENU.getVisibility() == View.VISIBLE){        MENU.setVisibility(View.INVISIBLE);        menuActual.setVisibility(View.INVISIBLE);    }else {        if (doubleBackToExitPressedOnce) {            super.onBackPressed();            moveTaskToBack(true);            return;        }else {            this.doubleBackToExitPressedOnce = true;            Toast.makeText(this, "Tap again to Exit!", Toast.LENGTH_SHORT).show();            new Handler().postDelayed(new Runnable() {                @Override                public void run() {                    doubleBackToExitPressedOnce=false;                }            }, 2000);        }    }}`我已经声明 boolean doubleBackToExitPressedOnce = false;该应用程序就显示该Toast语句而言"Press again to Exit"，但如果再次单击返回，该应用程序会显示"AppName isn't responding"努力弄清楚为什么会这样，这是漫长的一天。

Answer 1

做到在onBackPressed这样的：

private boolean doubleBackToExitPressedOnce = false;

private Handler handler;

private Runnable runnable;

@Override

public void onBackPressed() {

    if (MENU.getVisibility() == View.VISIBLE) {

        MENU.setVisibility(View.INVISIBLE);

        menuActual.setVisibility(View.INVISIBLE);

        return;

    }

    if (!doubleBackToExitPressedOnce) {

        doubleBackToExitPressedOnce = true;

        Toast.makeText(this, "Tap again to Exit!", Toast.LENGTH_SHORT).show();

        handler = new Handler();

        handler.postDelayed(runnable = new Runnable() {

            @Override

            public void run() {

                doubleBackToExitPressedOnce = false;

            }

        }, 2000);

        return;

    }

    // Removes the callBack

    handler.removeCallbacks(runnable);

    // Replace this next line with finishAffinity() if you want to close the app.

    super.onBackPressed();

}