对于我来说，我想将 Burger 图标更改为 Fragment 的 ActionBar 左侧的 Back Arrow 图标，因为我正在使用 @987654324 @。还在右侧添加一个菜单。
在 Main Activity 中，它已经设置好了 - 默认情况下，当 Android Studio 为我创建 Navigation Drawer 时 - 像这样：
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
DrawerLayout drawer = findViewById(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();
问题是如何自定义Fragment 中的ActionBar，所以当我转到Fragment 时，它会显示自定义的ActionBar 以及返回箭头 图标被点击，它应该离开片段并且ActionBar应该回到第一个状态。
在Fragment中（完整实现）：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true); // To show the menu options
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState){
super.onViewCreated(view, savedInstanceState);
showActionBar(); // the method to change ActionBar
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
// inflate the customized menu which already created in XML
getActivity().getMenuInflater().inflate(R.menu.fragment_menu, menu);
super.onCreateOptionsMenu(menu, inflater);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// add implementation when user select an item from the menu
switch (item.getItemId()) {
case R.id.option1:
// do something
return true;
case R.id.option2:
// do something
return true;
case R.id.option3:
// do something
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void showActionBar() {
// get the ToolBar from Main Activity
final Toolbar toolbar = getActivity().findViewById(R.id.toolbar);
// get the ActionBar from Main Activity
final ActionBar actionBar = ((AppCompatActivity)getActivity()).getSupportActionBar();
// inflate the customized Action Bar View
LayoutInflater inflater = (LayoutInflater) getActivity()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View v = inflater.inflate(R.layout.fragment_actionbar, null);
if (actionBar != null) {
// enable the customized view and disable title
actionBar.setDisplayShowCustomEnabled(true);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setCustomView(v);
// remove Burger Icon
toolbar.setNavigationIcon(null);
// add click listener to the back arrow icon
v.findViewById(R.id.back).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// reverse back the show
actionBar.setDisplayShowCustomEnabled(false);
actionBar.setDisplayShowTitleEnabled(true);
//get the Drawer and DrawerToggle from Main Activity
// set them back as normal
DrawerLayout drawer = getActivity().findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
getActivity(), drawer, toolbar, R.string.navigation_drawer_open,
R.string.navigation_drawer_close);
// All that to re-synchronize the Drawer State
toggle.syncState();
// Implement Back Arrow Icon
// so it goes back to previous Fragment
getActivity().onBackPressed();
}
});
}
}
fragment_actionbar.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_gravity="fill_horizontal" >
<ImageView
android:id="@+id/back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:src="@drawable/ic_menu_back"
android:layout_marginLeft="@dimen/_5sdp"
android:layout_alignParentStart="true"
android:layout_marginStart="@dimen/_5sdp" />
</RelativeLayout>
ic_menu_back.xml
<vector xmlns:android="http://schemas.android.com/apk/res/android"
android:width="24dp"
android:height="24dp"
android:viewportHeight="459"
android:viewportWidth="459">
<path
android:fillColor="#ffffff"
android:pathData="M178.5,140.25v-102L0,216.75l178.5,178.5V290.7c127.5,0,216.75,40.8,280.5,130.05C433.5,293.25,357,165.75,178.5,140.25z"/>
</vector>
fragment_menu.xml
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:background="@drawable/border_shadow">
<item
android:id="@+id/option1"
android:title="@string/show_profile"
app:showAsAction="never"/>
<item
android:id="@+id/option2"
android:title="@string/report_pic"
app:showAsAction="never"/>
<item
android:id="@+id/option3"
android:title="@string/delete_pic"
app:showAsAction="never"/>
</menu>