Android 如何在抽屉布局的NavigationView中设置未读通知计数？

我已经创建了一个内部使用

如何在
NavigationView
项目上设置未读通知计数器？
NavigationView
旨在成为实现符合材料设计指南的基本导航抽屉的简单方法

如果您想要的不仅仅是一个基本的导航抽屉（即带有文本导航项和可选标题的抽屉），您需要为导航抽屉创建自己的布局。
我建议您删除导航视图，并将导航抽屉元素作为片段添加，例如在DarawerLayout文件中

<android.support.v4.widget.DrawerLayout    xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<LinearLayout

然后，您可以将此片段添加到您的主要活动中，即

mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    navigationDrawerFragment = (NavigationDrawerFragment)
            getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);
    navigationDrawerFragment.setUp(R.id.fragment_navigation_drawer,mDrawerLayout, toolbar);

“setup”方法位于片段中，您可以在片段中初始化它

public void setUp(int fragmentId, DrawerLayout drawerLayout, final Toolbar toolbar) {

    containerView = getActivity().findViewById(fragmentId);
    mDrawerLayout = drawerLayout;
    mActionBarDrawerToggle = new ActionBarDrawerToggle(
            getActivity(), mDrawerLayout, toolbar,
            R.string.navigation_drawer_open, R.string.navigation_drawer_close
    ) {
        @Override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);

            }
            getActivity().invalidateOptionsMenu();

        }

        @Override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);


        }

}

在抽屉的布局文件中，添加要为其设置未读通知的元素，然后添加将其方向设置为垂直的相对布局，即

<RelativeLayout
    android:layout_below="@+id/drawer_layout_unread_notif"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="fill_parent">



在此垂直相对布局中，为图元添加另一个相对布局。这将是您在发布的图像中添加“警报”部分的地方。该相对布局应为水平布局，即

<RelativeLayout
        android:layout_below="@+id/drawer_items_1"
        android:orientation="horizontal"
        android:background="@drawable/drawer_selector"
        android:clickable="true"
        android:layout_width="match_parent"
        android:id="@+id/drawer_items_2"
        android:layout_height="48dp">

        <ImageView
            android:src="@drawable/ic_notification"
            android:padding="8dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            android:layout_centerVertical="true"
            android:layout_gravity="center_vertical"/>

        <TextView
            android:text="Notifications"
            android:textColor="@color/primary_text"
            android:layout_marginLeft="72dp"
            android:layout_centerVertical="true"
            android:layout_gravity="center_vertical"
            android:padding="8dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <TextView
            android:background="@color/red"
            android:layout_marginRight="10dp"
            android:id="@+id/drawer_notifications"
            android:layout_alignParentRight="true"
            android:padding="8dp"
            android:layout_centerVertical="true"
            android:textColor="@color/white"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />


    </RelativeLayout>



代码中的最后一个textview元素将包含要为未读通知添加的计数器。在xml中，其颜色设置为红色。从这里，使用它的ID（在oncreateview中）在导航抽屉片段类中获取对它的引用，并用计数器填充它

希望这有帮助
 更新答案：

使用支持库23.1.1或更高版本的
app:actionLayout
将支持如下自定义布局

创建自定义计数器布局，如下所示

菜单\u counter.xml：

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:gravity="center_vertical"
    android:textAppearance="@style/TextAppearance.AppCompat.Body2" />

<item
    android:id="@+id/navigation_drawer_item_1"
    android:icon="@drawable/ic_menu_1"
    android:title="@string/navigation_drawer_item_1"
    app:actionLayout="@layout/menu_counter"
    />

请注意，如果必须支持
Android 2.x
版本，则需要使用
MenuItemCompat

以前的答案（对于旧版本）：

使用
ListView
内部
NavigationView
解决，如下代码

<android.support.design.widget.NavigationView
    android:id="@+id/my_courses_nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header" >

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="150dp" > <!-- Give layout margin top according to "headerLayout" height -->

        <ListView
            android:id="@+id/left_drawer"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@android:color/white"
            android:cacheColorHint="@android:color/transparent"
            android:choiceMode="singleChoice"
            android:divider="@android:color/transparent"
            android:dividerHeight="0dp" />

    </FrameLayout>
</android.support.design.widget.NavigationView>

我相信，23个设计库中都添加了对这一点的支持

在菜单XML文件中，在
app
XML前缀中设置
actionLayout
：

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.user.myapplication.MainActivity" >
    <item android:id="@+id/menu_one"
        android:checkable="true"
        android:title="Unread items"
        app:actionLayout="@layout/unread_items"
        />
</menu>



然后让菜单包含布局计算未读项，可能使用自定义视图或片段获取数据
 我在这个网站上发现了这个易于实现的解决方案，请按照以下步骤操作

第1步：
创建一个Android Studio项目，而不是选择空活动，选择“导航抽屉活动”

第二步：
将“actionViewClass”属性添加到导航抽屉菜单（即menu/youractivityname\u drawer.xml）

第五步：
在需要的地方初始化initializeCountDrawer（）。它还可用于更新导航抽屉菜单项中的计数或徽章值

private void initializeCountDrawer(){

   //Gravity property aligns the text
   gallery.setGravity(Gravity.CENTER_VERTICAL);
   gallery.setTypeface(null, Typeface.BOLD);
   gallery.setTextColor(getResources().getColor(R.color.colorAccent));
   gallery.setText("99+");
   slideshow.setGravity(Gravity.CENTER_VERTICAL);
   slideshow.setTypeface(null,Typeface.BOLD);                                                                                                                    slideshow.setTextColor(getResources().getColor(R.color.colorAccent));
  //count is added     
  slideshow.setText("7");
}

来源：
通过读取反编译的NavigationView代码（找不到原始的…），似乎无法使用NavigationView实现这一点。你必须实现你自己的。这是你最好的例子question@SatishPathuri我问的是如何使用
NavigationView
？在您的链接中，它没有使用
NavigationView
。这是否回答了您的问题？完美的答案，这应该是保护我需要更多的按钮来投票。仅仅一个是不够的。真棒的回答！回答得很好（最新的部分在顶部）。需要注意的是，我必须将TextView包装在一个相对的窗口中，并在TextView上设置
android:layout\u centerInParent=“true”
，以便在使用可绘制背景时使其垂直居中。使用该方法，我只需调用
actionView？.findviewbyd（R.id.text\u view）
即可获得对TextView的引用。非常好用，感谢您的解决方案！这节省了我很多时间！更新后的答案从此处复制：
<item
    android:id="@+id/navigation_drawer_item_1"
    android:icon="@drawable/ic_menu_1"
    android:title="@string/navigation_drawer_item_1"
    app:actionLayout="@layout/menu_counter"
    />

private void setMenuCounter(@IdRes int itemId, int count) {
    TextView view = (TextView) navigationView.getMenu().findItem(itemId).getActionView();
    view.setText(count > 0 ? String.valueOf(count) : null);
}

<android.support.design.widget.NavigationView
    android:id="@+id/my_courses_nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header" >

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="150dp" > <!-- Give layout margin top according to "headerLayout" height -->

        <ListView
            android:id="@+id/left_drawer"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@android:color/white"
            android:cacheColorHint="@android:color/transparent"
            android:choiceMode="singleChoice"
            android:divider="@android:color/transparent"
            android:dividerHeight="0dp" />

    </FrameLayout>
</android.support.design.widget.NavigationView>

    private final String[] mMenuTitles = { getResources().getString(R.string.bookmarks), getResources().getString(R.string.alerts), getResources().getString(R.string.settings)  };
    private final int[] mMenuIconId = { R.drawable.ic_drawer_bookmarks, R.drawable.ic_drawer_alerts, R.drawable.ic_drawer_settings };


    ListView mDrawerList = (ListView) findViewById(R.id.left_drawer);
    mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

    private ArrayList<SlideMenuItem> drawerItemList = new ArrayList<SlideMenuItem>();           
    for( int i = 0; i < mMenuTitles.length; i++ ) {
        SlideMenuItem item = new SlideMenuItem();
        item.setTitle(mMenuTitles[i]);
        item.setIconID(mMenuIconId[i]);
        // item..setUnread(5) //set or update unread count & notify dataset changed to adapter
        drawerItemList.add(item);
    }

    MenuAdapter mMenuAdapter = new MenuAdapter( MyCoursesActivity.this, R.layout.drawer_list_item, drawerItemList);
    mDrawerList.setAdapter(mMenuAdapter);

private class DrawerItemClickListener implements ListView.OnItemClickListener {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        try {
            mDrawerLayout.closeDrawers();
            SlideMenuItem item =  (SlideMenuItem) parent.getItemAtPosition(position);
            switch (item.getIconId()) {

                case R.drawable.ic_drawer_bookmarks: {

                }
                break;
                case R.drawable.ic_drawer_alerts: {

                }
                break;
                case R.drawable.ic_drawer_settings: {

                }
                break;                  
                default: {
                }
                break;
            }
        } catch (Exception e) {             
        }

    }
}

public class MenuAdapter extends ArrayAdapter<SlideMenuItem> {

private Activity activity;
private List<SlideMenuItem> itemList;
private SlideMenuItem item;
private int row;

public MenuAdapter(Activity act, int resource, List<SlideMenuItem> arrayList) {
    super(act, resource, arrayList);
    this.activity = act;
    this.row = resource;
    this.itemList = arrayList;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    View view = convertView;
    ViewHolder holder;
    if (view == null) {
        LayoutInflater inflater = (LayoutInflater) activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = inflater.inflate(row, null);

        holder = new ViewHolder();
        holder.tvTitle = (TextView) view.findViewById(R.id.menu_title);
        holder.imgView = (ImageView) view.findViewById(R.id.menu_icon);
        holder.tvUnread = (TextView) view.findViewById(R.id.unread_count);
        view.setTag(holder);
    } else {
        holder = (ViewHolder) view.getTag();
    }

    if ((itemList == null) || ((position + 1) > itemList.size()))
        return view;

    item = itemList.get(position);

    holder.tvTitle.setText(item.getTitle());
    holder.imgView.setImageResource(item.getIconId());
    if( item.getUnreadCount() > 0 ) {
        holder.tvUnread.setVisibility(View.VISIBLE);
        holder.tvUnread.setText(item.getUnread());
        if( MyCoursesActivity.DRAWER_MENU_ALERTS_POSITION == position ) {
            holder.tvUnread.setBackgroundResource(R.drawable.round_unread_count_bg_red);    
        }
        else {
            holder.tvUnread.setBackgroundResource(R.drawable.round_unread_count_bg_green);
        }
    }
    else {
        holder.tvUnread.setVisibility(View.GONE);
    }
    return view;
}

public class ViewHolder {

    public TextView tvTitle;
    public ImageView imgView;
    public TextView tvUnread;
}

}

<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="vertical">

<RelativeLayout
android:id="@+id/drawar_list_view"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<ImageView
    android:id="@+id/menu_icon"
    android:layout_width="20dp"
    android:layout_height="20dp"
    android:layout_alignParentLeft="true"
    android:layout_centerVertical="true"
    android:layout_marginLeft="16dp"
    android:layout_marginRight="16dp"
    android:gravity="center_vertical"
    android:src="@drawable/ic_drawer" />

<TextView
    android:id="@+id/menu_title"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:layout_toLeftOf="@+id/unread_count"
    android:layout_toRightOf="@+id/menu_icon"
    android:minHeight="?attr/listPreferredItemHeightSmall"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:text="About Us"
    android:gravity="center_vertical"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/black" />

<TextView
    android:id="@+id/unread_count"
    android:layout_width="20dp"
    android:layout_height="20dp"
    android:layout_alignParentRight="true"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:layout_marginLeft="16dp"
    android:layout_marginRight="16dp"
    android:gravity="center" 
    android:text="99+"
    android:textColor="@android:color/white"
    android:textSize="10sp"
    android:visibility="gone" />

public class SlideMenuItem {

private Bitmap icon;
private String title;
private String unread;
private int iconID;

public String getTitle() {
    return title;
}

public void setTitle(String title) {
    this.title = title;
}

public Bitmap getIcon() {
    return icon;
}

public void setIcon(Bitmap icon) {
    this.icon = icon;
}

public int getIconId() {
    return iconID;
}

public void setIconID(int icon) {
    this.iconID = icon;
}

public String getUnread() {
    return unread;
}

public int getUnreadCount() {
    int count = Flinnt.INVALID;
    try {
        if( null != unread ) {
            count = Integer.parseInt(unread);
        }
    } catch (Exception e) {
    }
    return count;
}

public void setUnread(String unread) {
    this.unread = unread;
}

}

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.user.myapplication.MainActivity" >
    <item android:id="@+id/menu_one"
        android:checkable="true"
        android:title="Unread items"
        app:actionLayout="@layout/unread_items"
        />
</menu>

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">

<group android:checkableBehavior="single">
    <item
        android:id="@+id/nav_camera"
        android:icon="@drawable/ic_menu_camera"
        android:title="Import" />
    <item
        android:id="@+id/nav_gallery"
        app:actionViewClass="android.widget.TextView"
        android:icon="@drawable/ic_menu_gallery"
        android:title="Gallery" />
    <item
        android:id="@+id/nav_slideshow"
        app:actionViewClass="android.widget.TextView"
        android:icon="@drawable/ic_menu_slideshow"
        android:title="Slideshow" />
    <item
        android:id="@+id/nav_manage"
        android:icon="@drawable/ic_menu_manage"
        android:title="Tools" />
</group>

//Create these objects above OnCreate()of your main activity
TextView slideshow,gallery;

//These lines should be added in the OnCreate() of your main activity
 NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
 navigationView.setNavigationItemSelectedListener(this);

gallery=(TextView) MenuItemCompat.getActionView(navigationView.getMenu().
        findItem(R.id.nav_gallery));

slideshow=(TextView) MenuItemCompat.getActionView(navigationView.getMenu().
        findItem(R.id.nav_slideshow));

//This method will initialize the count value
initializeCountDrawer();

private void initializeCountDrawer(){

   //Gravity property aligns the text
   gallery.setGravity(Gravity.CENTER_VERTICAL);
   gallery.setTypeface(null, Typeface.BOLD);
   gallery.setTextColor(getResources().getColor(R.color.colorAccent));
   gallery.setText("99+");
   slideshow.setGravity(Gravity.CENTER_VERTICAL);
   slideshow.setTypeface(null,Typeface.BOLD);                                                                                                                    slideshow.setTextColor(getResources().getColor(R.color.colorAccent));
  //count is added     
  slideshow.setText("7");
}