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…

android:layout_width="match_parent"

android:layout_height="match_parent"

>

android:id="@+id/ll_content_part"

android:layout_width="match_parent"

android:layout_height="match_parent"

>

android:id="@+id/ll_function"

android:layout_alignParentBottom="true"

android:orientation="horizontal"

android:layout_width="match_parent"

android:layout_height="wrap_content">

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"/>

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"/>

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"/>

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"/>

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编程圈。