java - 与 selectedItem (java) 相关的 Android BottomNavigationView 和 NavController 问题
问题描述
我有一个带有 BottomNavigationView 的 MainActivity，上面有 5 个 menuItem，每个都指向一个片段（主页、帮助、合同、账单、帐户）
在 Home 片段上，有一个指向第 6 个“联系人”片段的链接，该片段不是底部导航栏的项目。目前，当我单击此链接时，它会按预期显示“联系人”片段，但在底部导航栏上，“主页”图标仍然是选中的。我希望改为检查“帐户”图标，因为“联系人”片段属于“帐户”部分（您可以通过帐户>查看联系人访问它）
我使用 navcontroller/navigationUI 进行导航。这是我的 Home_Fragment 的代码：
package com.example.myapp.Fragments;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.Navigation;
import androidx.navigation.fragment.NavHostFragment;
import com.example.techcrea.HelpfulTools.UserModel;
import com.example.techcrea.R;
/**
* A simple {@link Fragment} subclass.
*/
public class Home extends Fragment implements View.OnClickListener {
//VIEW ATTRIBUTES ##############################################################################
/**
* The text that displays our username
*/
private TextView displayUserName;
/**
* The horizontal dividers
*/
private View divider1, divider2, divider3, divider4, divider5;
/**
* The small icons left of each row
*/
private ImageView iconBills, iconAccount, iconContracts,iconContacts;
/**
* The pics for each type of contract
*/
private ImageView imgFiber, imgPhone, imgOther;
/**
* Clickable lines
*/
private LinearLayout accountRow, billRow, contractsRow, contactsRow, helpBlock;
//DATA ATTRIBUTES ##############################################################################
private UserModel user;
/***
* Fragment sole constructor
*/
public Home() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//Here we set the text that displays the user name
View view = inflater.inflate(R.layout.fragment_home, container, false);
loadViewComponents(view);
user= ViewModelProviders.of(this).get(UserModel.class);
displayUserName.setText(user.getUser().getValue().getUserName());
return view;
}
/**
* Binds the design components to variables
*/
public void loadViewComponents(View view){
displayUserName = view.findViewById(R.id.txtWelcomeUser);
divider1 = view.findViewById(R.id.dvd1);
divider2 = view.findViewById(R.id.dvd2);
divider3 = view.findViewById(R.id.dvd3);
divider4 = view.findViewById(R.id.dvd4);
divider5 = view.findViewById(R.id.dvd5);
iconBills = view.findViewById(R.id.iconBills);
iconAccount = view.findViewById(R.id.iconAccount);
iconContracts = view.findViewById(R.id.iconContracts);
iconContacts = view.findViewById(R.id.iconContacts);
imgFiber = view.findViewById(R.id.img_fiber);
imgPhone = view.findViewById(R.id.img_phone);
imgOther = view.findViewById(R.id.img_other);
accountRow = view.findViewById(R.id.row_account);
billRow = view.findViewById(R.id.row_bills);
contractsRow = view.findViewById(R.id.row_contracts);
contactsRow = view.findViewById(R.id.row_contact);
helpBlock = view.findViewById(R.id.row_help);
setListeners();
}
/**
* The onClick Listeners for the menu rows.
*/
public void setListeners(){
accountRow.setOnClickListener(this);
billRow.setOnClickListener(this);
helpBlock.setOnClickListener(this);
contactsRow.setOnClickListener(this);
contractsRow.setOnClickListener(this);
}
/**
* this method redirects the user in the belonging section, depending on which row he clicked
* @param v the source of the click
*/
@Override
public void onClick(View v) {
if (v.equals(accountRow)) {
NavHostFragment.findNavController(this).navigate(R.id.action_mnuHome_to_mnuAccount);
} else if (v.equals(billRow)) {
Navigation.findNavController(v).navigate(R.id.action_mnuHome_to_mnuBills);
} else if (v.equals(helpBlock)) {
Navigation.findNavController(v).navigate(R.id.action_mnuHome_to_mnuHelp);
} else if (v.equals(contactsRow)) {
Navigation.setViewNavController();
NavHostFragment.findNavController(this).navigate(R.id.action_global_contactsList);
} else if (v.equals(contractsRow)) {
Navigation.findNavController(v).navigate(R.id.action_mnuHome_to_mnuContracts);
}
}}
这是我的 mainActivity 布局，其中包含导航栏：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
tools:context=".Activities.HomeActivity">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="56dp"
android:backgroundTint="@color/toolbar_color"
app:logo="@drawable/login_logo"
app:titleMargins="5dp"
android:paddingStart="10dp"
android:paddingEnd="10dp" />
<fragment
android:id="@+id/fragmentContainer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/bottom_navigation"
android:layout_below="@id/toolbar"
android:layout_marginTop="0dp"
android:layout_marginBottom="0dp"
android:scrollbarStyle="insideOverlay"
android:name="androidx.navigation.fragment.NavHostFragment"
app:navGraph="@navigation/botnavigation"
app:defaultNavHost="true">
</fragment>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="56dp"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true"
app:itemBackground="@color/navbar_background_color"
app:itemIconTint="@color/navbar_colors"
app:itemTextColor="@color/navbar_colors"
app:menu="@menu/navbar"/>
</RelativeLayout>
这是我的底视图导航栏：
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/mnuHome"
android:icon="@drawable/ic_home_black_24dp"
android:title="@string/home" />
<item
android:id="@+id/mnuHelp"
android:icon="@drawable/icon_help"
android:title="@string/help" />
<item
android:id="@+id/mnuContracts"
android:icon="@drawable/icon_contracts"
android:title="@string/contracts" />
<item
android:id="@+id/mnuBills"
android:icon="@drawable/icon_bill"
android:title="@string/bills" />
<item
android:id="@+id/mnuAccount"
android:icon="@drawable/icon_account"
android:title="@string/account" />
</menu>
最后是我的导航图：
<?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/botnavigation"
app:startDestination="@id/mnuHome">
<fragment
android:id="@+id/mnuHome"
android:name="com.example.techcrea.Fragments.Home"
android:label="fragment_home"
tools:layout="@layout/fragment_home" >
<action
android:id="@+id/action_mnuHome_to_mnuContracts"
app:destination="@id/mnuContracts" />
<action
android:id="@+id/action_mnuHome_to_mnuHelp"
app:destination="@id/mnuHelp" />
<action
android:id="@+id/action_mnuHome_to_mnuAccount"
app:destination="@id/mnuAccount" />
<action
android:id="@+id/action_mnuHome_to_mnuBills"
app:destination="@id/mnuBills" />
</fragment>
<fragment
android:id="@+id/mnuAccount"
android:name="com.example.techcrea.Fragments.AccountMain"
android:label="fragment_account_main"
tools:layout="@layout/fragment_account_main" />
<fragment
android:id="@+id/mnuBills"
android:name="com.example.techcrea.Fragments.BillsMain"
android:label="fragment_bills_main"
tools:layout="@layout/fragment_bills_main" />
<fragment
android:id="@+id/mnuHelp"
android:name="com.example.techcrea.Fragments.Help"
android:label="fragment_help"
tools:layout="@layout/fragment_help" />
<fragment
android:id="@+id/contactsList"
android:name="com.example.techcrea.Fragments.ContactsList"
android:label="fragment_account_watchcontacts"
tools:layout="@layout/fragment_account_watchcontacts" />
<fragment
android:id="@+id/mnuContracts"
android:name="com.example.techcrea.Fragments.ContractsMain"
android:label="fragment_contracts_main"
tools:layout="@layout/fragment_contracts_main" /><action android:id="@+id/action_global_contactsList" app:destination="@id/contactsList"/>
</navigation>
还有我声明我的 navcontroller 的 MainActivity ：
//Default Android needs
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.NavigationUI;
import com.example.techcrea.HelpfulTools.UserModel;
import com.example.techcrea.R;
import com.google.android.material.bottomnavigation.BottomNavigationView;
import com.google.android.material.bottomnavigation.LabelVisibilityMode;
//Fragments
//Android libraries
//Our fragments
//Bottom botnavigation bar
//Toolbar
/**
* This is the "home" activity and it contains all the fragments we will navigate in.
* This activity is called by the LoginActivity.
* @author Caroline
*/
public class HomeActivity extends AppCompatActivity {
/**
* Persistent user
*/
private UserModel user;
private NavController navController;
@Override
protected void onCreate(Bundle savedInstanceState) {
//Android default code, do not touch _______________________________________________________
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
//__________________________________________________________________________________________
//Toolbar instanciation
Toolbar toolbar = findViewById(R.id.toolbar);
toolbar.setBackgroundColor(getResources().getColor(R.color.toolbar_color));
toolbar.setTitle("");
setSupportActionBar(toolbar);
//Bottom Navigation : selected item by default at activity launch
BottomNavigationView bView = findViewById(R.id.bottom_navigation); //Bottom botnavigation bar
bView.setLabelVisibilityMode(LabelVisibilityMode.LABEL_VISIBILITY_LABELED); //This line is to force the display of texts under nav icons. Otherwise, only the active icon has its label visible.
//Making it reactive to in-fragment links
//We add the fragment container layout to our botnavigation controller so it observes botnavigation.
// To change the way the navController interacts with layout, please see Res>Navigation>Nav_graph.xml
navController = Navigation.findNavController(this,R.id.fragmentContainer);
NavigationUI.setupWithNavController(bView, navController);
NavigationUI.setupActionBarWithNavController(this,navController);
}
}
如果您看到令人发指的错误，请宽容，我是开发新手，这是我的第一个“专业”工作，我几天前才开始。而且我是法国人，所以我的英语有点烂，但我必须为即将到来的考试写英文评论。在我的实习结束之前，我没有时间完成这个应用程序，所以我尽量让实习生在我之后更清楚地了解它。
非常感谢<3
解决方案
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