Android导航组件“向上按钮”打开抽屉导航答案

【问题标题】：Android Navigation Component 'Up button' opens drawer navigationAndroid导航组件“向上按钮”打开抽屉导航
【发布时间】：2019-01-31 13:07:40
【问题描述】：

我正在尝试使用带有导航图和导航控制器的导航组件来实现简单的导航。我的 MainActivity 带有带有汉堡图标和应用程序标题的操作栏、抽屉导航和内容区域。

内容区是我展示不同片段的地方。

内容区域首先加载我的 homescreenFragment，其中包含 4 个按钮（新闻、事件、时间表、配置文件） - 每个按钮都将片段加载到我的 MainActivity 的内容区域中。它工作正常，唯一的问题是：当我按下 新闻按钮 并从我的 主屏幕 导航到我的 NewsFragment 时，它会加载片段 OK 并将操作栏标题更改为新闻。 汉堡包图标已更改为“向上按钮”图标，但当我按下它时，应用程序会打开导航抽屉，就像我按下汉堡包图标一样，而不是将我导航回主屏幕。

如何使向上按钮向上而不显示左侧导航抽屉？

这是我的 MainActivity.java：

import android.os.Bundle;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;

import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.NavigationUI;

public class MainActivity extends AppCompatActivity  {

    Toolbar m_toolbar;
    DrawerLayout m_drawer;
    ActionBarDrawerToggle m_toggle;
    NavigationView m_navigationView;
    NavController m_navController;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        m_toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(m_toolbar);

        m_drawer = findViewById(R.id.drawer_layout);

        m_navigationView = findViewById(R.id.nav_drawer_view);

        m_navController = Navigation.findNavController(this, R.id.content);

        m_toggle = new ActionBarDrawerToggle(
                this, m_drawer, m_toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        m_drawer.addDrawerListener(m_toggle);
        //m_toggle.syncState();

        //connect actionbar icon and drawer with nav controller
        NavigationUI.setupWithNavController(m_navigationView, m_navController);
        NavigationUI.setupActionBarWithNavController(this, m_navController);
        NavigationUI.setupActionBarWithNavController(this, m_navController, m_drawer);

    }

    @Override
    public boolean onSupportNavigateUp() {
        return Navigation.findNavController(this, R.id.nav_drawer_view).navigateUp() || super.onSupportNavigateUp();
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }


}

我的activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout 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"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">

    <LinearLayout
        android:orientation="vertical"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

        <android.support.design.widget.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/AppTheme.AppBarOverlay">

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                app:popupTheme="@style/AppTheme.PopupOverlay" />

        </android.support.design.widget.AppBarLayout>

            <FrameLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent">
                <fragment
                    android:id="@+id/content"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    app:layout_behavior="@string/appbar_scrolling_view_behavior"
                    android:name="androidx.navigation.fragment.NavHostFragment"
                    app:navGraph="@navigation/nav_graph"
                    app:defaultNavHost="true"/>

            </FrameLayout>

    </LinearLayout>

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

</android.support.v4.widget.DrawerLayout>

导航图：

<?xml version="1.0" encoding="utf-8"?>
<navigation 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"
    android:id="@+id/nav_graph"
    app:startDestination="@id/homeScreenFragment">

    <fragment
        android:id="@+id/homeScreenFragment"
        android:name="com.mysample.meganews.Fragments.HomeScreenFragment"
        android:label="@string/app_name"
        tools:layout="@layout/home_screen_fragment" >
        <action
            android:id="@+id/action_to_news"
            app:destination="@id/newsFragment"
            app:enterAnim="@anim/nav_default_enter_anim"
            app:exitAnim="@anim/nav_default_exit_anim" />
        <action
            android:id="@+id/action_to_events"
            app:destination="@id/eventsFragment"
            app:enterAnim="@anim/nav_default_pop_enter_anim"
            app:exitAnim="@anim/nav_default_pop_exit_anim" />
    </fragment>
    <fragment
        android:id="@+id/newsFragment"
        android:name="com.mysample.meganews.Fragments.NewsFragment"
        android:label="@string/hs_title_news"
        tools:layout="@layout/news_fragment" />
    <fragment
        android:id="@+id/eventsFragment"
        android:name="com.mysample.meganews.Fragments.EventsFragment"
        android:label="events_fragment"
        tools:layout="@layout/events_fragment" />
</navigation>

HomeScreenFragment.java 文件：

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;

import androidx.navigation.NavController;
import androidx.navigation.Navigation;


/**
 * A simple {@link Fragment} subclass.
 */
public class HomeScreenFragment extends Fragment {


    public HomeScreenFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.home_screen_fragment, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        RelativeLayout rl_news = view.findViewById(R.id.ll_news_btn);
        RelativeLayout rl_events = view.findViewById(R.id.ll_events_btn);

        rl_news.setOnClickListener(Navigation.createNavigateOnClickListener(R.id.action_to_news));
        rl_events.setOnClickListener(Navigation.createNavigateOnClickListener(R.id.action_to_events));
    }
}

build.gradle 文件：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.mysample.meganews"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:design:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.android.support:support-v4:28.0.0'
    implementation 'android.arch.lifecycle:extensions:1.1.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'android.arch.navigation:navigation-fragment:1.0.0-alpha11'
    implementation 'android.arch.navigation:navigation-ui:1.0.0-alpha11'
}

【问题讨论】：

标签： android-actionbar android-architecture-navigation

【解决方案1】：

这个问题是由于混合了不同的 API 造成的。这是正确的代码：

activity_main.xml：

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@color/colorPrimary"
            android:theme="@style/ThemeOverlay.AppCompat.Dark" />
                <fragment
                    android:id="@+id/content"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    app:layout_behavior="@string/appbar_scrolling_view_behavior"
                    android:name="androidx.navigation.fragment.NavHostFragment"
                    app:navGraph="@navigation/nav_graph"
                    app:defaultNavHost="true"/>

    </LinearLayout>

    <com.google.android.material.navigation.NavigationView
        android:id="@+id/nav_drawer_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:headerLayout="@layout/nav_header_main"
        app:menu="@menu/activity_main_drawer" />

</androidx.drawerlayout.widget.DrawerLayout>

MainActivity.java：

import android.os.Bundle;


import com.google.android.material.navigation.NavigationView;

import androidx.core.view.GravityCompat;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.NavigationUI;

import android.view.MenuItem;
import android.view.ViewParent;

public class MainActivity extends AppCompatActivity
{
    private Toolbar mToolbar;
    private DrawerLayout mDrawer;
    private ActionBarDrawerToggle mToggle;
    private NavigationView mNavigationView;
    private NavController mNavController;

    private MainViewModel mViewModel;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        mViewModel = ViewModelProviders.of(this).get(MainViewModel.class);

        setupNavigation();
    }

    private void setupNavigation()
    {
        mToolbar = findViewById(R.id.toolbar);
        setSupportActionBar(mToolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        mDrawer = findViewById(R.id.drawerLayout);
        mNavigationView = findViewById(R.id.nav_drawer_view);

        mNavigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(MenuItem menuItem) {

//                // we need this line to handle the navigation
//                boolean handled = NavigationUI.onNavDestinationSelected(menuItem, mNavController);
//                if (handled) {
//                    ViewParent parent = mNavigationView.getParent();
//                    if (parent instanceof DrawerLayout) {
//                        ((DrawerLayout) parent).closeDrawer(mNavigationView);
//                    }
//                }

                return true;
            }
        });

        mNavController = Navigation.findNavController(this, R.id.content);
        NavigationUI.setupActionBarWithNavController(this, mNavController, mDrawer);
        // Tie nav graph to items in nav drawer
        NavigationUI.setupWithNavController(mNavigationView, mNavController);
    }


    @Override
    public boolean onSupportNavigateUp() {
        //return Navigation.findNavController(this, R.id.content).navigateUp();
        //return mNavController.navigateUp()  || super.onSupportNavigateUp();
        return NavigationUI.navigateUp(mNavController, mDrawer);
    }

    @Override
    public void onBackPressed() {
        if (mDrawer.isDrawerOpen(GravityCompat.START)) {
            mDrawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

【讨论】：

【解决方案2】：

我遇到了同样的问题，并使用以下解决方法修复了它。

    mNavController.addOnDestinationChangedListener(new NavController.OnDestinationChangedListener() {
        @Override
        public void onDestinationChanged(@NonNull NavController controller,
                                         @NonNull NavDestination destination, @Nullable Bundle arguments) {          
            if (mAppBarConfiguration.getTopLevelDestinations().contains(destination.getId())) {
                mToggle.setDrawerIndicatorEnabled(true);
            } else {
                mToggle.setDrawerIndicatorEnabled(false);
            }
        }
    });

还要确保将点击侦听器设置为 ActionBarDrawerToggle，如下所示。

    mToggle.setToolbarNavigationClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mActivity.onBackPressed();
        }
    });

【讨论】：

【解决方案3】：

默认情况下导航处理这个，你不必为此显式处理监听器。在您的活动中覆盖“onSupportNavigationUp”

override fun onSupportNavigateUp(): Boolean {
    return NavigationUI.navigateUp(navController, drawer_layout)
}

并在上面做。它会默认处理返回按钮和汉堡图标。

【讨论】：