從一個(gè)Activity跳轉(zhuǎn)到另一個(gè)Activity的指定Fragment，附底部菜單欄的實(shí)現(xiàn)

這篇具有很好參考價(jià)值的文章主要介紹了從一個(gè)Activity跳轉(zhuǎn)到另一個(gè)Activity的指定Fragment，附底部菜單欄的實(shí)現(xiàn)。希望對大家有所幫助。如果存在錯(cuò)誤或未考慮完全的地方，請大家不吝賜教，您也可以點(diǎn)擊"舉報(bào)違法"按鈕提交疑問。

先實(shí)現(xiàn)底部菜單欄

這部分參考B站視頻Springboot:
2022最新版】Android Studio 安裝 Android（安卓）開發(fā)零基礎(chǔ)入門到精通全套教程P118-119
效果圖： activity界面返回到fragment頁面,android,ui,android studio

忘了需不需要添加依賴了，大概率是本來就有不用添加，但還是把可能有關(guān)的依賴先貼上來

    implementation 'androidx.navigation:navigation-fragment:2.3.5'
    implementation 'androidx.navigation:navigation-ui:2.3.5'

先在res下的menu包里（沒有就建一個(gè)menu包）新建一個(gè)buttom_nav_menu的資源文件（xml文件），代碼為：

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

    <item
        android:id="@+id/bottom_home"
        android:title="@string/bottom_title_home"
        android:icon="@drawable/home"/>
    <item
        android:id="@+id/bottom_notice"
        android:title="@string/bottom_title_notice"
        android:icon="@drawable/notice"
    />
    <item
        android:id="@+id/bottom_mine"
        android:title="@string/bottom_title_mine"
        android:icon="@drawable/person"/>
    <item
        android:id="@+id/bottom_unfold"
        android:title="@string/bottom_title_unfold"
        android:icon="@drawable/more"
        />

</menu>

然后在HomeActivity的基礎(chǔ)上創(chuàng)建四個(gè)對應(yīng)的fragment文件
然后HomeActivity里的代碼

package com.example.academymanageapp.ui;

import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import android.content.ClipData;
import android.content.Intent;
import android.os.Bundle;
import android.os.Parcelable;
import android.view.MenuItem;

import com.example.academymanageapp.R;
import com.example.academymanageapp.ui.base.BaseActivity;
import com.example.academymanageapp.ui.home.HomeFragment;
import com.example.academymanageapp.ui.mine.MineFragment;
import com.example.academymanageapp.ui.notice.NoticeFragment;
import com.example.academymanageapp.ui.unfold.UnfoldFragment;
import com.google.android.material.bottomnavigation.BottomNavigationView;

public class HomeActivity extends BaseActivity implements BottomNavigationView.OnNavigationItemSelectedListener {

    private Fragment[] fragments; //fragment數(shù)組，用來存儲(chǔ)底部菜單欄用到的fragment
    private int lastFragmentIndex = 0;//切換前的fragment
    private int nextFragmentIndex;//切換后的fragment
    private int fragmentFlag;

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

    }

    @Override
    protected void initViews() {

        //初始化fragments
        fragments = new Fragment[]{new HomeFragment(),new NoticeFragment(), new MineFragment(),new UnfoldFragment()};
        //注冊一個(gè)監(jiān)聽，用來監(jiān)聽用戶點(diǎn)擊底部菜單里的哪一個(gè)fragment
        BottomNavigationView bottomNavigationView = find(R.id.main_bottom_navigation);
        
        //設(shè)置默認(rèn)的
        getSupportFragmentManager().beginTransaction().add(R.id.main_frame,fragments[0]).commit();
    }


    @Override
    protected int getLayoutId() {
        return R.layout.activity_home;
    }

    @Override
    //獲得用戶點(diǎn)擊的menuItem
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
//        item.getItemId();//獲得用戶點(diǎn)擊的部件的Id
        item.setChecked(true);//給點(diǎn)中的item設(shè)置checked
        switch (item.getItemId()){
            case R.id.bottom_home:
                switchFragment(0);
                break;
            case R.id.bottom_notice:
                switchFragment(1);
                break;
            case R.id.bottom_mine:
                switchFragment(2);
                break;
            case R.id.bottom_unfold:
                switchFragment(3);
                break;
        }
        return false;
    }

    //默認(rèn)點(diǎn)擊是home，所以要?jiǎng)?chuàng)建一個(gè)fragment的切換
    private void switchFragment(int to){
        if (lastFragmentIndex == to){ //如果切換前后一致則不切換
            return;
        }
        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
        //如果沒有添加過,則添加對應(yīng)的fragment
        if (!fragments[to].isAdded()){
            fragmentTransaction.add(R.id.main_frame,fragments[to]);
        }else {
            fragmentTransaction.show(fragments[to]);//否則就展示出來
        }
        //添加后將之前的隱藏
        fragmentTransaction.hide(fragments[lastFragmentIndex]).commitAllowingStateLoss();
        lastFragmentIndex = to;
    }

}

fragment里的代碼：

package com.example.academymanageapp.ui.mine;

import android.view.View;
import androidx.core.content.ContextCompat;
import com.example.academymanageapp.R;
import com.example.academymanageapp.databinding.FragmentMineBinding;
import com.example.academymanageapp.ui.base.BaseFragment;

public class MineFragment extends BaseFragment {
    private FragmentMineBinding binding;

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        binding = FragmentMineBinding.inflate(inflater, container, false);
        View root = binding.getRoot();
        return root;
        }
        
    @Override
    protected void initViews() {
    }

    @Override
    protected int getLayoutId() {
        return R.layout.fragment_mine;
    }
}

其他fragment同理

實(shí)現(xiàn)跳轉(zhuǎn)

參考文章：android 如何從activity跳轉(zhuǎn)到另一個(gè)activity下指定的fragment

問題描述：在做畢設(shè)的時(shí)候，需要實(shí)現(xiàn)點(diǎn)擊返回按鈕時(shí)從activityA（即ActivityDetailActivity）返回到進(jìn)入前的界面（可能是fragmentA（即homeFragment），也有可能是fragmentB（即mineFragment），兩者都屬于HomeActivity）。

思路：從ActivityDetailActivity跳轉(zhuǎn)時(shí)，帶flag跳轉(zhuǎn)，根據(jù)flag跳轉(zhuǎn)到指定的fragment

ActivityDetailActivity部分的代碼：

 Intent intent = new Intent();
 intent.setClass(ActivityDetailActivity.this,HomeActivity.class);
 intent.putExtra("fragment_flag",2);
 startActivity(intent);

HomeActivity部分只需要對傳回來的值進(jìn)行一個(gè)判斷，根據(jù)值switch到指定的fragment就好，添加的代碼：

fragmentFlag = getIntent().getIntExtra("fragment_flag",0);
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        switch (fragmentFlag){
            case 0:
                switchFragment(0);
                //使對應(yīng)的底部菜單欄的Item處于被點(diǎn)擊的狀態(tài)（即點(diǎn)擊都更改顏色）
                bottomNavigationView.setSelectedItemId(R.id.bottom_home);
                //調(diào)用底部菜單欄函數(shù)，以實(shí)現(xiàn)根據(jù)點(diǎn)擊底部菜單欄實(shí)現(xiàn)fragment的跳轉(zhuǎn)
                bottomNavigationView.setOnNavigationItemSelectedListener(this);
                //記得加break，否則頁面不會(huì)變化
                break;
            case 1:
                switchFragment(1);
                bottomNavigationView.setSelectedItemId(R.id.bottom_notice);
                bottomNavigationView.setOnNavigationItemSelectedListener(this);
                break;
            case 2:
                switchFragment(2);
                bottomNavigationView.setSelectedItemId(R.id.bottom_mine);
                bottomNavigationView.setOnNavigationItemSelectedListener(this);
                break;
            case 3:
                switchFragment(3);
                bottomNavigationView.setSelectedItemId(R.id.bottom_unfold);
                bottomNavigationView.setOnNavigationItemSelectedListener(this);
                break;
        }
        transaction.commit();

此時(shí)HomeActivity的完整代碼是：文章來源地址http://www.zghlxwxcb.cn/news/detail-771345.html

package com.example.academymanageapp.ui;

import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import android.content.ClipData;
import android.content.Intent;
import android.os.Bundle;
import android.os.Parcelable;
import android.view.MenuItem;

import com.example.academymanageapp.R;
import com.example.academymanageapp.ui.base.BaseActivity;
import com.example.academymanageapp.ui.home.HomeFragment;
import com.example.academymanageapp.ui.mine.MineFragment;
import com.example.academymanageapp.ui.notice.NoticeFragment;
import com.example.academymanageapp.ui.unfold.UnfoldFragment;
import com.google.android.material.bottomnavigation.BottomNavigationView;

public class HomeActivity extends BaseActivity implements BottomNavigationView.OnNavigationItemSelectedListener {

    private Fragment[] fragments; //fragment數(shù)組，用來存儲(chǔ)底部菜單欄用到的fragment
    private int lastFragmentIndex = 0;//切換前的fragment
    private int nextFragmentIndex;//切換后的fragment
    private int fragmentFlag;

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

    }

    @Override
    protected void initViews() {

        //初始化fragments
        fragments = new Fragment[]{new HomeFragment(),new NoticeFragment(), new MineFragment(),new UnfoldFragment()};
        //注冊一個(gè)監(jiān)聽，用來監(jiān)聽用戶點(diǎn)擊底部菜單里的哪一個(gè)fragment
        BottomNavigationView bottomNavigationView = find(R.id.main_bottom_navigation);

        fragmentFlag = getIntent().getIntExtra("fragment_flag",0);
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        switch (fragmentFlag){
            case 0:
                switchFragment(0);
                //使對應(yīng)的底部菜單欄的Item處于被點(diǎn)擊的狀態(tài)（即點(diǎn)擊都更改顏色）
                bottomNavigationView.setSelectedItemId(R.id.bottom_home);
                //調(diào)用底部菜單欄函數(shù)，以實(shí)現(xiàn)根據(jù)點(diǎn)擊底部菜單欄實(shí)現(xiàn)fragment的跳轉(zhuǎn)
                bottomNavigationView.setOnNavigationItemSelectedListener(this);
                //記得加break，否則頁面不會(huì)變化
                break;
            case 1:
                switchFragment(1);
                bottomNavigationView.setSelectedItemId(R.id.bottom_notice);
                bottomNavigationView.setOnNavigationItemSelectedListener(this);
                break;
            case 2:
                switchFragment(2);
                bottomNavigationView.setSelectedItemId(R.id.bottom_mine);
                bottomNavigationView.setOnNavigationItemSelectedListener(this);
                break;
            case 3:
                switchFragment(3);
                bottomNavigationView.setSelectedItemId(R.id.bottom_unfold);
                bottomNavigationView.setOnNavigationItemSelectedListener(this);
                break;
        }
        transaction.commit();

        //設(shè)置默認(rèn)的
        getSupportFragmentManager().beginTransaction().add(R.id.main_frame,fragments[0]).commit();
    }


    @Override
    protected int getLayoutId() {
        return R.layout.activity_home;
    }

    @Override
    //獲得用戶點(diǎn)擊的menuItem
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
//        item.getItemId();//獲得用戶點(diǎn)擊的部件的Id
        item.setChecked(true);//給點(diǎn)中的item設(shè)置checked
        switch (item.getItemId()){
            case R.id.bottom_home:
                switchFragment(0);
                break;
            case R.id.bottom_notice:
                switchFragment(1);
                break;
            case R.id.bottom_mine:
                switchFragment(2);
                break;
            case R.id.bottom_unfold:
                switchFragment(3);
                break;
        }
        return false;
    }

    //默認(rèn)點(diǎn)擊是home，所以要?jiǎng)?chuàng)建一個(gè)fragment的切換
    private void switchFragment(int to){
        if (lastFragmentIndex == to){ //如果切換前后一致則不切換
            return;
        }
        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
        //如果沒有添加過,則添加對應(yīng)的fragment
        if (!fragments[to].isAdded()){
            fragmentTransaction.add(R.id.main_frame,fragments[to]);
        }else {
            fragmentTransaction.show(fragments[to]);//否則就展示出來
        }
        //添加后將之前的隱藏
        fragmentTransaction.hide(fragments[lastFragmentIndex]).commitAllowingStateLoss();
        lastFragmentIndex = to;
    }

}

到了這里，關(guān)于從一個(gè)Activity跳轉(zhuǎn)到另一個(gè)Activity的指定Fragment，附底部菜單欄的實(shí)現(xiàn)的文章就介紹完了。如果您還想了解更多內(nèi)容，請?jiān)谟疑辖撬阉鱐OY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！