onNavigationItemSelected在NavigationView中不起作用

Question

请有人帮我处理导航抽屉中的碎片，由于某种原因我无法让他们工作，所有代码看起来都正确。

Here是源代码的链接。

Answer 1

看看你的MainActivity.java。

您已经在NavigationView.OnNavigationItemSelectedListener中实现了MainActivity的回调，如下所示，

@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
    // blah blah
}

还要检查setupDrawerContent方法。

private void setupDrawerContent(NavigationView navigationView) {
    navigationView.setNavigationItemSelectedListener(
            new NavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(MenuItem menuItem) {
                    menuItem.setChecked(true);
                    drawerLayout.closeDrawers();
                    return true;
                }
            });
}

在这种方法中，您将创建一个本地OnNavigationItemSelectedListener。

所以你没有使用你在OnNavigationItemSelectedListener覆盖的MainActivity。

解决方案是使用this作为setNavigationItemSelectedListener的参数。通过这样做你所有的点击将去onNavigationItemSelected MainActivity而不是去当地的onNavigationItemSelected。

private void setupDrawerContent(NavigationView navigationView) {
    navigationView.setNavigationItemSelectedListener(this);
}

同时将本地onNavigationItemSelected中的代码移动到onNavigationItemSelected的MainActivity。

所以你的onNavigationItemSelected会是这样的，

@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
    // Handle navigation view item clicks here.
    int id = menuItem.getItemId();
    menuItem.setChecked(true);
    drawerLayout.closeDrawers();

    if (id == R.id.nav_home) {
        // Handle the home action
        Toast.makeText(this, "Home", Toast.LENGTH_SHORT).show();
    } else if (id == R.id.nav_the_wetlands) {
        Toast.makeText(this, "The Wetlands", Toast.LENGTH_SHORT).show();
        TheWetlandsFragment theWetlandsFragment = new TheWetlandsFragment();
        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.relativelayout_for_fragment, theWetlandsFragment, theWetlandsFragment.getTag()).commit();
    } else if (id == R.id.nav_the_mistbelt_forests) {
        Toast.makeText(this, "The Mistbelt Forests", Toast.LENGTH_SHORT).show();
    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

同时更改您的activity_main_drawer_view.xml，以解决导航抽屉中的多选问题，

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <group android:checkableBehavior="single">
        <item
            android:id="@+id/nav_home"
            android:icon="@drawable/ic_dashboard"
            android:title="Home" />
    </group>

    <item android:title="Information">
        <group android:checkableBehavior="single">
            <item
                android:id="@+id/nav_the_wetlands"
                android:icon="@drawable/ic_event"
                android:title="The Wetlands" />
            <item
                android:id="@+id/nav_the_mistbelt_forests"
                android:icon="@drawable/ic_event"
                android:title="The Mistbelt Forests" />
            <item
                android:id="@+id/nav_the_grasslands"
                android:icon="@drawable/ic_event"
                android:title="The Grasslands" />
        </group>
    </item>

    <item android:title="Quick Go To">
        <group android:checkableBehavior="single">
            <item
                android:id="@+id/nav_accommodation"
                android:icon="@drawable/ic_event"
                android:title="Accommodation" />
            <item
                android:id="@+id/nav_cuisine"
                android:icon="@drawable/ic_forum"
                android:title="Cuisine" />
            <item
                android:id="@+id/nav_leisure_activites"
                android:icon="@drawable/ic_forum"
                android:title="Leisure &amp; Activites" />
            <item
                android:id="@+id/nav_agri_tourism"
                android:icon="@drawable/ic_forum"
                android:title="Agri-tourism" />
            <item
                android:id="@+id/nav_education"
                android:icon="@drawable/ic_forum"
                android:title="Education" />
            <item
                android:id="@+id/nav_arts_crafts_decor"
                android:icon="@drawable/ic_forum"
                android:title="Arts, Crafts &amp; DeCor" />
            <item
                android:id="@+id/nav_selective_shopping"
                android:icon="@drawable/ic_forum"
                android:title="Selective Shopping" />
            <item
                android:id="@+id/nav_for_children"
                android:icon="@drawable/ic_forum"
                android:title="For Children" />
        </group>
    </item>

    <item android:title="Midlands Animals">
        <group android:checkableBehavior="single">
            <item
                android:id="@+id/nav_midlands_birding_checklist"
                android:icon="@drawable/ic_dashboard"
                android:title="Midlands Birding Checklist" />
            <item
                android:id="@+id/nav_midlands_mammals_checklist"
                android:icon="@drawable/ic_dashboard"
                android:title="Midlands Mammals Checklist" />
        </group>
    </item>

</menu>

祝好运。

Answer 2

使用此代码：

navigationView = (NavigationView) findViewById(R.id.navigationView); 
navigationView.bringToFront();

Answer 3

一段时间后我也遇到了同样的问题，最后我意识到我没有写下面代码的第二行

navigationView = (NavigationView) findViewById(R.id.navigation_view);        
navigationView.setNavigationItemSelectedListener(this);

你确保你写的相同，否则你的听众将无法工作