Android手机底部导航栏实现

运行效果：

image.png

运行环境：
AndroidStdio
1.创建一个类继承于ViewGroup管理每一个控件的布局

public class TabBarView extends ViewGroup {


    //保存所有标签的模型数据
    private ArrayList<TabModel> items;
    public TabBarView(Context context) {
        super(context);

    }

    public TabBarView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        if (items != null) {
            //每个tab的尺寸
            float density = getResources().
                    getDisplayMetrics().density;

            int width = (int) (70 * density);
            //计算间距
            int padding = (getWidth()-width*items.size()) /
                    (items.size()+1);

            for (int i = 0; i < items.size(); i++){
                //获取图片id对应的Drawable对象
                TabModel model = items.get(i);


                //创建一个标签视图
                TabBotton v = new TabBotton(getContext(),model.icon_normal,model.icon_select,model.title);


                //具体布局
                int left = (i+1)*padding + i * width;
                int top = (int) (5*density);
                int right = left + width;
                int bottom = (int) (getHeight()-5*density);
                v.layout(left,top,right,bottom);
                //添加
                addView(v);
            }
        }
    }

    //提供一个内部类
    //用来管理数据模型
    public static class TabModel{
        public int icon_normal;
        public int icon_select;
        public String title;

        public TabModel(int icon_normal, int icon_select, String title) {
            this.icon_normal = icon_normal;
            this.icon_select = icon_select;
            this.title = title;
        }
    }

    public void setItems(ArrayList<TabModel> items) {
        this.items = items;

    }

}

2.在xml中配置

<?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=".MainActivity"
    android:id="@+id/root">
    <swu.zht.a11_30test.TabBarView
        android:id="@+id/tab_bar"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:layout_alignParentBottom="true"
        android:background="@color/colorAccent"

        >

    </swu.zht.a11_30test.TabBarView>


</RelativeLayout>

3.创建一个类管理控件的具体内容

public class TabBotton extends AppCompatButton {
   private int normal;
   private int select;
   private String title;

   //记录一下标签传递的内容
   public TabBotton(Context context) {
       super(context);
   }

   public TabBotton(Context context,int normal,int select,String title) {
       this(context);
       this.normal = normal;
       this.select = select;
       this.title = title;

       float density = getResources().getDisplayMetrics().density;
       //获取id对应的drawable对象
       Drawable drawable = getResources().getDrawable(normal);
       //设置图片的尺寸
       drawable.setBounds(0,0,(int)(32*density),(int)(32*density));
       //设置正常状态的图片和文字
       setCompoundDrawables(null,drawable,null,null
               );
       setText(title);
   }
   public TabBotton(Context context, AttributeSet attrs) {
       super(context, attrs);
   }
}

4.在主界面里面设置具体的属性、内容值

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();
    }
    public void init(){
        //获取对象
        TabBarView tabBar = findViewById(R.id.tab_bar);
        //配置显示的内容
        ArrayList<TabBarView.TabModel> items = new ArrayList<>();
        //创建标签的对象
        TabBarView.TabModel star = new TabBarView.TabModel(R.drawable.activity1,R.drawable.activity2,"活动");
        TabBarView.TabModel friend = new TabBarView.TabModel(R.drawable.people2,R.drawable.people1,"好友");
        items.add(star);
        items.add(friend);
        items.add(star);
        items.add(friend);
        tabBar.setItems(items);
    }
}

图片资源：：

动态 (1).png

动态.png

联系人 (1).png

联系人.png

消息 (1).png

消息.png