Android Fragment实现底部通知栏

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。