如何以编程方式从Android的导航抽屉中删除子菜单?

问题描述：

我正在开发一个Android应用程序.首先，让我告诉你我不是专业人士.我现在要做的是根据情况在菜单中添加子菜单.但是我需要经常在我的应用中执行此操作.但是我的问题是我第一次在菜单中添加了子菜单.

I am developing an Android app. Firstly, let me tell you that I am not professional. What I am doing now is I am adding submenu to menu depending on a condition. But I need to do it very often in my app. But my problem is I added a submenu to the menu as first time.

但是第二次当我根据条件更新菜单时，现有子菜单不会被删除，新的子菜单会附加到导航抽屉中.如何删除以编程方式添加到菜单的子菜单?为什么我的代码没有删除它?

But second time when I update menu depending on condition, existing submenu is not removed and new submenu is appended to navigation drawer. How can I remove submenu that is programmatically added to menu? Why my code is not removing it?

这是我的代码

public void updateAuthUI()
    {
        isLoggedIn = tempStorage.getBoolean(getResources().getString(R.string.pref_is_logged_in),false);
        Menu menu = leftDrawer.getMenu();
        menu.removeItem(getResources().getInteger(R.integer.logout_item_id));
        menu.removeItem(getResources().getInteger(R.integer.login_item_id));
        menu.removeItem(getResources().getInteger(R.integer.register_item_id));
        SubMenu authSubMenu = menu.addSubMenu("Auth");

        if(isLoggedIn)
        {
            authSubMenu.add(1,getResources().getInteger(R.integer.logout_item_id),99,"Sign out");
        }
        else{
            authSubMenu.add(1,getResources().getInteger(R.integer.register_item_id),97,"Register");
            authSubMenu.add(1,getResources().getInteger(R.integer.login_item_id),98,"Sign in").setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
                @Override
                public boolean onMenuItemClick(MenuItem item) {
                    openLoginActivity();
                    item.setChecked(true);
                    return true;
                }
            });
        }
    }

这是我的问题的屏幕截图

Here is the screenshot of my problem

如您所见，身份验证"子菜单已添加，但未删除现有子菜单.

As you can see Auth submenu is appended without removing existing one.

答

尝试

authSubMenu.clear();

在您的第一个

authSubMenu.add();

我刚刚在使用第三方库的Android应用中使用了SubMenu.clear()，并且需要从操作栏中清除不需要的子菜单. (我实际上是想完全删除该子菜单，这是我可以找到的唯一方法.它似乎起作用.)

I just used SubMenu.clear() in an Android app where I was using a third-party library, and I needed to clear out an unwanted submenu from the action bar. (I actually wanted to remove the submenu completely, and this was the only way I could find to do it. It seemed to work.)

与您的情况不同，在这里，authSubMenu是您刚刚通过menu.addSubMenu("Auth")添加的菜单，因此您希望它为空.但是，正如您所看到的，它显然不是空的:而是返回该标题的现有子菜单. (我找不到达到这种效果的文档；我只是按照您报告的结果进行操作.)

That's different from your situation, where authSubMenu is a menu you just added via menu.addSubMenu("Auth"), so you would expect it to be empty. But, as you've seen, it apparently isn't empty: rather, addSubMenu("Auth") returns the existing submenu of that title. (I can't find documentation to that effect; I'm just going by the results you've reported.)

如果确实如此，那么authSubMenu.clear()将从子菜单中删除所有现有项目.

If that really is the case, as it appears to be, then authSubMenu.clear() will remove all existing items from the submenu.

如何以编程方式从Android的导航抽屉中删除子菜单?

相关推荐