Android Material Design之BottomAppBar(八)

1.上图

2. 资源引入

implementation 'androidx.appcompat:appcompat:1.3.0'
implementation 'com.google.android.material:material:1.4.0'

3. 属性

属性	描述
android:id	控件id
android:layout_width	控件长度
android:layout_height	控件高度
app:backgroundTint	控件背景颜色
app:hideOnScroll	滚动时隐藏
app:menu	菜单选项

4. 源代码
   activity_bootom_app_bar.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />


    <com.google.android.material.bottomappbar.BottomAppBar
        android:id="@+id/bottomAppBar"
        android:layout_width="match_parent"
        android:layout_height="56dp"
        android:layout_gravity="bottom"
        app:backgroundTint="@color/black"
        app:hideOnScroll="true"
        app:menu="@menu/bab_menu" />

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@mipmap/icon_scan"
        app:fabSize="normal"
        app:layout_anchor="@id/bottomAppBar" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>

BootomAppBarActivity.java

package com.yyf.demo;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.ContextCompat;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.yyf.demo.databinding.ActivityBottomAppBarBinding;

import java.util.ArrayList;
import java.util.List;

public class BottomAppBar extends AppCompatActivity {
    private ActivityBottomAppBarBinding binding;
    private static final String TAG = "BottomAppBar";
    private List<String> list = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityBottomAppBarBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());


        for (int i = 0; i < 100; i++) {
            list.add(String.valueOf(i));
        }

        binding.recyclerView.setLayoutManager(new LinearLayoutManager(getBaseContext()));
        binding.recyclerView.setAdapter(new RecyclerView.Adapter() {
            @NonNull
            @Override
            public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_text, parent, false);
                Holder holder = new Holder(view);
                return holder;
            }

            @Override
            public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
                Holder holder1 = (Holder) holder;
                TextView textView = holder1.itemView.findViewById(R.id.tv_item);
                if (position % 2 == 0) {
                    textView.setBackgroundColor(ContextCompat.getColor(getBaseContext(), R.color.purple_500));
                } else {
                    textView.setBackgroundColor(ContextCompat.getColor(getBaseContext(), R.color.purple_700));
                }
                textView.setText(list.get(position));
            }


            @Override
            public int getItemCount() {
                return list.size();
            }
        });
    }

    private static class Holder extends RecyclerView.ViewHolder {
        public Holder(@NonNull View itemView) {
            super(itemView);
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        Log.d(TAG, "onOptionsItemSelected: " + item.getItemId());
        switch (item.getItemId()) {
            case R.id.scan:
                Log.d(TAG, "onOptionsItemSelected: " + item.getTitle());
                break;
        }
        return super.onOptionsItemSelected(item);
    }
}

menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/more"
        android:icon="@drawable/ic_baseline_more_vert_24"
        android:title="更多"
        app:showAsAction="always">
        <menu>
            <item
                android:id="@+id/scan"
                android:title="扫一扫" />
        </menu>
    </item>
</menu>

5. 注意事项
   想要实现FloatingActionButton 嵌入BottomAppBar中得效果,必须使用CoordinatorLayout包裹,在FloatingActionButton中使用锚点app:layout_anchor=“引入BottomAppBar得控件Id”