我的主要活动布局中有工具栏和框架布局（用于片段）。我必须在每个片段中显示工具栏。但问题是每个片段都有不同的动态变化的背景图像。工具栏菜单图标用于导航抽屉的打开和关闭操作。我将如何处理这些问题？
【问题讨论】：
在发布代码块之前，让我们先了解一下我们要做什么。
1.创建一个包含所有片段的 HomeActivity。
这里是activity_home.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">
<include
layout="@layout/app_bar_home"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.design.widget.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/nav_header_home"
app:menu="@menu/activity_home_drawer" />
</android.support.v4.widget.DrawerLayout>
这里是app_bar_home.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
navigationview 的其他 xml——activity_home_drawer.xml 包含导航抽屉内容，nav_header_home.xml 是导航抽屉标题布局。
2.来HomeActivity.java@的java部分
public class HomeActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener{
private HomeBean bean;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
ButterKnife.bind(this);
initListener();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
//this menu contains all the common menu item actions
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
//common options bar item click here i have notifications icon common for all the fragments
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
switch (item.getItemId()){
case R.id.action_notifications:
AppUtils.launchActivity(HomeActivity.this, NotificationActivity.class,intentData);
return false;
default:
return super.onOptionsItemSelected(item);
}
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
// Handle navigation view item clicks here.
Fragment selectedFragment = null;
switch (item.getItemId()){
case R.id.nav_dashboard:
//you can cache this fragment in case of repeated creations
selectedFragment = new DashBoardFragment();
}
break;
}
if(selectedFragment != null){
displayFragment(selectedFragment);
DrawerLayout drawer = ButterKnife.findById(this,R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
}
return true;
}
private void displayFragment(Fragment fragment) {
if(fragment !=null){
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.content_frame, fragment);
ft.commit();
}
}
@Override
public void initToolBar() {}
public void setToolbar(Toolbar toolbar){
setSupportActionBar(toolbar);
setActionBarToggle(toolbar);
}
private void setActionBarToggle(Toolbar toolbar) {
DrawerLayout drawer = ButterKnife.findById(this, R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open,
R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
}
@Override
public void initListener() {
NavigationView navigationView = ButterKnife.findById(this,R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
//as the first item is show by default
navigationView.getMenu().getItem(0).setChecked(true);
}
@Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
}
现在作为一个例子，让我们看看片段是如何编写的。
public class SettingsFragment extends Fragment {
@BindView(R.id.toolbar)
Toolbar toolbar;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_settings,container,false);
ButterKnife.bind(this,view);
return view;
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
((HomeActivity)getActivity()).setToolbar(toolbar);
}
}
对应片段xmlfragment_settings.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="Fragment Name">
<android.support.design.widget.AppBarLayout
android:id="@+id/notification_appbar"
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"
app:title="@string/settings"/>
</android.support.design.widget.AppBarLayout>
<include layout="@layout/content_settings" />
</android.support.design.widget.CoordinatorLayout>
对应的xmlcontent_settings.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="@dimen/min_widget_padding"
android:id="@+id/nsv_settings_content"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
// your content goes here
</<android.support.v4.widget.NestedScrollView>
我希望这可以清楚地说明如何做，如果您有任何其他疑问，请发表评论。
【讨论】：
使用此代码。我帮忙了
public class MyFragment extends Fragment {
public void onCreate(Bundle savedInstanceState) {
setHasOptionsMenu(true);// To enable actionbar in fragments
super.onCreate(savedInstanceState);
}
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
//Here it is necessary to connect the layout menu
inflater.inflate(R.menu.fragment2, menu);
super.onCreateOptionsMenu(menu, inflater);
}
}
【讨论】：