Android底部导航栏未打开与其链接的活动

Question

我是Android开发的新手。我正在学习UI设计。我想要一个解决方案，其中有一个底部栏，其中5个选项直接链接到5个不同的活动。我从其他堆栈溢出答案中获得了Java解决方案（How to change activity on bottom navigation button click?） - 第二个答案是sushil，但它没有活动 - XML文件可供我理解。

像这样的底栏：

基于底栏加载的活动：

Answer 1

bottomNavigationView.setOnNavigationItemSelectedListener(
    new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            switch (item.getItemId()) {
                case R.id.action_favorites:
                     Intent intent1 = new Intent(this, AnActivity.class);
                     startActivity(intent1);
                     break;
                case R.id.action_schedules:
                  Intent intent2 = new Intent(this, AnotherActivity.class);
                  startActivity(intent2);
                  break;
                case R.id.action_music:
                   Intent intent3 = new Intent(this, AnotherActivity.class);
                startActivity(intent3);
                break;
            }
            return true;
        }
    });

Answer 2

根据附件中的图片，您应该使用Fragment代替Activity 5个不同的MenuItem或选项来实现所需的输出。

1。为5个不同的Fragments创建5个不同的MenuItem。 例如：MatchingFragment，WatchListFragment，RatesFragment，DealsFragment和ListingFragment。

2。将OnNavigationItemSelectedListener添加到NavigationView，然后根据您选择的Fragment更改MenuItem。使用以下代码更改Fragment：

// Set action to perform when any menu-item is selected.
bottomNavigationView.setOnNavigationItemSelectedListener(
    new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            // Change Fragment
            selectFragment(item);
            return false;
        }
    });

/**
 * Perform action when any item is selected.
 *
 * @param item Item that is selected.
 */
protected void selectFragment(MenuItem item) {

    item.setChecked(true);

    switch (item.getItemId()) {
        case R.id.action_matching:
            // Action to perform when Matching Menu item is selected.
            pushFragment(new MatchingFragment());
            break;
        case R.id.action_watch_list:
            // Action to perform when WatchList Menu item is selected.
            pushFragment(new WatchListFragment());
            break;
        case R.id.action_rates:
            // Action to perform when Rates Menu item is selected.
            pushFragment(new RatesFragment());
            break;
        case R.id.action_deals:
            // Action to perform when Deals Menu item is selected.
            pushFragment(new DealsFragment());
            break;
        case R.id.action_listing:
            // Action to perform when Listing Menu item is selected.
            pushFragment(new ListingFragment());
            break;
    }
}

/**
 * Method to push any fragment into given id.
 *
 * @param fragment An instance of Fragment to show into the given id.
 */
protected void pushFragment(Fragment fragment) {
    if (fragment == null)
        return;

    FragmentManager fragmentManager = getFragmentManager();
    if (fragmentManager != null) {
        FragmentTransaction ft = fragmentManager.beginTransaction();
        if (ft != null) {
            ft.replace(R.id.rootLayout, fragment);
            ft.commit();
        }
    }
}

以下是完整的教程：Android Bottom Navigation View Tutorial With Example

希望这会有所帮助〜

Answer 3

基本活动：

public abstract class BaseActivity extends AppCompatActivity implements BottomNavigationView.OnNavigationItemSelectedListener {

protected BottomNavigationView navigationView;

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

    navigationView = (BottomNavigationView) findViewById(R.id.bottom_navigation);
    navigationView.setOnNavigationItemSelectedListener(this);
}

@Override
protected void onStart() {
    super.onStart();
    updateNavigationBarState();
}

// Remove inter-activity transition to avoid screen tossing on tapping bottom navigation items
@Override
public void onPause() {
    super.onPause();
    overridePendingTransition(0, 0);
}

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
    navigationView.postDelayed(() -> {
        int itemId = item.getItemId();
        if (itemId == R.id.navigation_analysis) {
            startActivity(new Intent(getApplicationContext(), AnalysisActivity.class));
        } else if (itemId == R.id.navigation_dashboard) {
            startActivity(new Intent(getApplicationContext(), DashboardActivity.class));
        } else if (itemId == R.id.navigation_profile) {
            startActivity(new Intent(getApplicationContext(), ProfileActivity.class));
        }
        finish();
    }, 100);
    return true;
}

private void updateNavigationBarState(){
    int actionId = getNavigationMenuItemId();
    selectBottomNavigationBarItem(actionId);
}

void selectBottomNavigationBarItem(int itemId) {
    Menu menu = navigationView.getMenu();
    for (int i = 0, size = menu.size(); i < size; i++) {
        MenuItem item = menu.getItem(i);
        boolean shouldBeChecked = item.getItemId() == itemId;
        if (shouldBeChecked) {
            item.setChecked(true);
            break;
        }
    }
}

abstract int getContentViewId();

abstract int getNavigationMenuItemId();

}

确保在onNavigationSelected（）中使用getApplicationContext。

仪表板活动：

public class DashboardActivity extends BaseActivity {

@Override
int getContentViewId() {
    return R.layout.activity_dashboard ;
}

@Override
int getNavigationMenuItemId() {
    return R.id.navigation_dashboard;
}  }

类似地-像这样进行其他活动。

XML PART

bottom_navigation.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.BottomNavigationView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?android:attr/windowBackground"
app:menu="@menu/navigation"
/>

navigation.xml

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

<item
    android:id="@+id/navigation_analysis"
    android:icon="@drawable/ic_home_black_24dp"
    android:title="@string/title_analysis" />

<item
    android:id="@+id/navigation_dashboard"
    android:icon="@drawable/ic_dashboard_black_24dp"
    android:title="@string/title_dashboard" />

<item
    android:id="@+id/navigation_profile"
    android:icon="@drawable/ic_notifications_black_24dp"
    android:title="@string/title_profile" />

</menu>

activity_dashboard.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    android:id="@+id/frame_dashboard">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/title_dashboard"/>
</FrameLayout>

<include
    layout="@layout/bottom_navigation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom"
    />


</LinearLayout>

类似地-像这样制作其他xml文件。 希望对您有帮助