Android Fragment实现底部通知栏，供大家参考，具体内容如下

截图如下：

1. 第一步先要创建fragment（动态注册）

然后将两个勾选取消掉（还有一种是自己手动创建）
会自动生成相对应的layout布局，剩下的要根据自己的需求了

2.在Activity的布局里写好四个按钮

这里不是重点…

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" ><LinearLayout android:id="@+id/ll_content_part" android:layout_width="match_parent" android:layout_height="match_parent" ></LinearLayout><LinearLayout android:id="@+id/ll_function" android:layout_alignParentBottom="true" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="wrap_content"><Button android:id="@+id/btn_msg_list" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textSize="13dp" android:onClick="click" android:text="msg"/> <Button android:id="@+id/btn_contact" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textSize="13dp" android:onClick="click" android:text="contact"/> <Button android:id="@+id/btn_disc" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textSize="13dp" android:onClick="click" android:text="disc"/> <Button android:id="@+id/btn_me" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textSize="13dp" android:onClick="click" android:text="me"/></LinearLayout></RelativeLayout>

3.Activity的代码

其中定义了四个整型常量记录了四个按钮的状态，还有一个当前状态，进而判断当前点击按钮的状态，点击切换文字颜色和图标
每次判断四个Fragment的引用是否为空，不为空就不需要每次在new一遍Fragment
replace每次都会重新初始化fragment，它是先remove掉相同id的fragment，再add当前fragment。
add不会回每次都初始化fragment，一般配合hide()和show()方法

public class MainActivity extends AppCompatActivity { private Button btn_contact; private Button btn_disc; private Button btn_me; private Button btn_msg_list; private FragmentManager fragmentManager; private MsgListFragment msgListFragment; private ContactFragment contactFragment; private DiscoveryFragment discoveryFragment; private MeFragment meFragment; private final int STATE_MSG =1; private final int STATE_CON =2; private final int STATE_DIS =3; private final int STATE_ME =4; private int currentState; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); initData(); chageButtonColor(currentState,STATE_MSG); } private void initData() { fragmentManager = getFragmentManager(); switchFragment(this.STATE_MSG); } private void initView() { btn_contact = (Button) findViewById(R.id.btn_contact); btn_disc = (Button) findViewById(R.id.btn_disc); btn_me = (Button) findViewById(R.id.btn_me); btn_msg_list = (Button) findViewById(R.id.btn_msg_list); } public void click(View view) { switch (view.getId()){ case R.id.btn_msg_list: switchFragment(this.STATE_MSG); break; case R.id.btn_contact: switchFragment(this.STATE_CON); break; case R.id.btn_disc: switchFragment(this.STATE_DIS); break; case R.id.btn_me: switchFragment(this.STATE_ME); break; } } private void switchFragment(int toState) { if (toState == currentState) return; chageButtonColor(currentState,toState); this.currentState=toState; FragmentTransaction transaction = this.fragmentManager.beginTransaction(); Fragment fragment=msgListFragment; switch (toState){ case STATE_DIS: if (discoveryFragment == null) discoveryFragment= new DiscoveryFragment(); fragment= discoveryFragment; break; case STATE_ME: if (meFragment == null) meFragment= new MeFragment(); fragment= meFragment; break; case STATE_CON: if (contactFragment == null) contactFragment= new ContactFragment(); fragment= contactFragment; break; case STATE_MSG: if (msgListFragment == null) msgListFragment= new MsgListFragment(); fragment= msgListFragment; break; } transaction.replace(R.id.ll_content_part,fragment); transaction.commit(); } private void chageButtonColor(int currentState,int toState){ switch (currentState){ case STATE_DIS: this.btn_disc.setTextColor(Color.BLACK); break; case STATE_ME: this.btn_me.setTextColor(Color.BLACK); break; case STATE_CON: this.btn_contact.setTextColor(Color.BLACK); break; case STATE_MSG: this.btn_msg_list.setTextColor(Color.BLACK); break; } switch (toState){ case STATE_DIS: this.btn_disc.setTextColor(Color.GREEN); break; case STATE_ME: this.btn_me.setTextColor(Color.GREEN); break; case STATE_CON: this.btn_contact.setTextColor(Color.GREEN); break; case STATE_MSG: this.btn_msg_list.setTextColor(Color.GREEN); break; } }}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。