• Android RecycleView实现混合Item布局


    首先来看看效果吧:

    效果预览.png

    本实例来自于慕课网的视屏http://www.imooc.com/video/13046,实现步骤可以自己去观看视屏,这里只记录了下实现的代码。

    添加依赖:

    (1) 在项目的build.gradle文件中添加下面的依赖

    compile 'com.android.support:recyclerview-v7:25.0.0'

    (2) 也可以在下图中自动进行依赖,选择RecycleView即可。

     

    代码部分

    直接代码传送门
    MainActivity

    public class MainActivity extends AppCompatActivity {
    
        private RecyclerView mRecyclerView;
        private MyAdapter mMyAdapter;
    
    
        private int colors[] = {android.R.color.holo_blue_bright,android.R.color.black,android.R.color.holo_red_dark};
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            initView();
            initData();
        }
    
        private void initView() {
            mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerView);
            mRecyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL,
                    false));
            mMyAdapter = new MyAdapter(this);
            mRecyclerView.setAdapter(mMyAdapter);
    
        }
    
        private void initData() {
            List<Person>  list= new ArrayList<>();
            for (int i = 0; i < 20; i++) {
                Person p = new Person();
                int type = (int) (Math.random()*3+1);
                p.type = type;
                p.content="content"+1;
                p.avaterColor = colors[type-1];
                p.name = "name"+i;
                list.add(p);
            }
            mMyAdapter.addList(list);
            mMyAdapter.notifyDataSetChanged();
        }
    }

    bean对象Person类

    /**
     * Created by 24540 on 2017/3/13.
     */
    
    public class Person {
        public  static final int TYPE_ONE = 1;
        public  static final int TYPE_TWO = 2;
        public  static final int TYPE_THREE = 3;
    
        protected int type;
        protected int avaterColor;
        protected int contentColor;
        protected String name;
        protected String content;
    
        public String getContent() {
            return content;
        }
    
        public void setContent(String content) {
            this.content = content;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public int getContentColor() {
            return contentColor;
        }
    
        public void setContentColor(int contentColor) {
            this.contentColor = contentColor;
        }
    
        public int getAvaterColor() {
            return avaterColor;
        }
    
        public void setAvaterColor(int avaterColor) {
            this.avaterColor = avaterColor;
        }
    
        public int getType() {
            return type;
        }
    
        public void setType(int type) {
            this.type = type;
        }
    
        public static int getTypeThree() {
            return TYPE_THREE;
        }
    
        public static int getTypeTwo() {
            return TYPE_TWO;
        }
        public static int getTypeOne() {
            return TYPE_ONE;
        }
    }

    RecycleView的适配器

    public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    
        private LayoutInflater mLayoutInflater;
    
        private List<Person> mList = new ArrayList<>();
    
        private Context mContext;
    
        public MyAdapter(Context mContext) {
            this.mContext = mContext;
            mLayoutInflater = LayoutInflater.from(mContext);
        }
    
        //使用此方法从获取数据
        public void addList(List<Person> list){
            mList.addAll(list);
        }
    
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            //根据不同的viewType,创建并返回影响的ViewHolder
            switch (viewType){
                case Person.TYPE_ONE:
                    return new TypeOneHolder(mLayoutInflater.inflate(R.layout.item_type_one,parent,false));
                case Person.TYPE_TWO:
                    return new TypeTwoHolder(mLayoutInflater.inflate(R.layout.item_type_two,parent,false));
                case Person.TYPE_THREE:
                    return new TypeThreeHolder(mLayoutInflater.inflate(R.layout.item_type_three,parent,false));
            }
            return null;
        }
    
        @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
            //抽象出TypeAbstartViewHolder,所以在进行绑定的时候可以直接调用
            ((TypeAbstartViewHolder)holder).bindHolder(mList.get(position));
        }
    
        @Override
        public int getItemViewType(int position) {
            return mList.get(position).getType();
        }
    
        @Override
        public int getItemCount() {
            return mList.size();
        }
    }

    关键的一点,TypeAbstartViewHolder 抽象出bindHolder方法,优雅实现加载不同item布局,代码如下:

    public abstract class TypeAbstartViewHolder extends RecyclerView.ViewHolder {
        public TypeAbstartViewHolder(View itemView) {
            super(itemView);
        }
        public abstract void bindHolder(Person person);
    }

    继承自上面抽象的方法,实现加载不同item布局TypeOneHolder:

    public class TypeOneHolder extends TypeAbstartViewHolder {
        private ImageView avater;
        private TextView name;
    
        public TypeOneHolder(View itemView) {
            super(itemView);
            avater = (ImageView) itemView.findViewById(R.id.avater);
            name = (TextView) itemView.findViewById(R.id.name);
        }
        //为ViewHolder绑定数据
        @Override
        public void bindHolder(Person person) {
            avater.setBackgroundResource(person.getAvaterColor());
            name.setText(person.getName());
        }
    }

    TypeTwoHolde代码如下:

    public class TypeTwoHolder extends TypeAbstartViewHolder {
        private ImageView avater;
        private TextView name;
        private TextView content;
    
        public TypeTwoHolder(View itemView) {
            super(itemView);
            avater = (ImageView) itemView.findViewById(R.id.avater);
            name = (TextView) itemView.findViewById(R.id.name);
            content = (TextView) itemView.findViewById(R.id.content);
        }
    
    
        //为ViewHolder绑定数据
        @Override
        public void bindHolder(Person person) {
            avater.setBackgroundResource(person.getAvaterColor());
            name.setText(person.getName());
            content.setText(person.getContent());
        }
    }

    TypeThreeHolder的代码如下:

    public class TypeThreeHolder extends TypeAbstartViewHolder {
        private ImageView avater;
        private TextView name;
        private TextView content;
        private ImageView iv;
    
        public TypeThreeHolder(View itemView) {
            super(itemView);
            avater = (ImageView) itemView.findViewById(R.id.avater);
            name = (TextView) itemView.findViewById(R.id.name);
            content = (TextView) itemView.findViewById(R.id.content);
            iv = (ImageView) itemView.findViewById(R.id.content_color);
        }
    
        //为ViewHolder绑定数据
        @Override
        public void bindHolder(Person person) {
            avater.setBackgroundResource(person.getAvaterColor());
            name.setText(person.getName());
            content.setText(person.getContent());
            iv.setBackgroundResource(person.getAvaterColor());
        }
    }

    xml文件代码部分:只放出了item_type_three部分的代码:

    <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="horizontal"
        android:background="@android:color/white"
        android:layout_width="match_parent"
        android:gravity="center_vertical"
        android:layout_height="60dp">
    
        <ImageView
            android:id="@+id/avater"
            android:layout_marginLeft="4dp"
            android:layout_width="40dp"
            android:layout_height="40dp"/>
    
        <LinearLayout
            android:layout_toRightOf="@id/avater"
            android:layout_marginLeft="5dp"
            android:orientation="vertical"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">
    
            <TextView
                android:id="@+id/name"
                android:text="type_one_textview"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
    
            <TextView
                android:id="@+id/content"
                android:layout_marginTop="5dp"
                android:text="type_one_textview"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
        </LinearLayout>
    
        <ImageView
            android:layout_alignParentRight="true"
            android:layout_marginRight="10dp"
            android:id="@+id/content_color"
            android:layout_width="100dp"
            android:layout_height="40dp"/>
    </RelativeLayout>

    通过recycleView实现两个不同布局混搭,只需要修改mainActivity如下:

    public class MainActivity extends AppCompatActivity {
    
        private RecyclerView mRecyclerView;
        private MyAdapter mMyAdapter;
    
    
        private int colors[] = {android.R.color.holo_blue_bright, android.R.color.black, android.R.color.holo_red_dark};
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            initView();
            initData();
        }
    
        private void initView() {
            mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerView);
    
            //构造参数里面的2表示的是一行有两列
            final GridLayoutManager manager = new GridLayoutManager(this, 2);
            mRecyclerView.setLayoutManager(manager);
            manager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
                @Override
                public int getSpanSize(int position) {
                    int type = mRecyclerView.getAdapter().getItemViewType(position);
                    //若是TYPE_THREE,占用两列,否则占用一列
                    if (type == Person.TYPE_THREE) {
                        return manager.getSpanCount();
                    } else {
                        return 1;
                    }
                }
            });
            mMyAdapter = new MyAdapter(this);
    
            //给布局里的子view添加边距
            mRecyclerView.addItemDecoration(new RecyclerView.ItemDecoration() {
                @Override
                public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
                    GridLayoutManager.LayoutParams layoutParams = (GridLayoutManager.LayoutParams) view.getLayoutParams();
                    int spanSize = layoutParams.getSpanSize();
                    int spanIndex = layoutParams.getSpanIndex();
                    outRect.top = 20;
                    if (spanSize != manager.getSpanCount()) {
                        if (spanIndex == 0) {
                            outRect.right = 0;
                        } else {
                            outRect.right = 10;
                        }
                    }
                }
            });
            mRecyclerView.setAdapter(mMyAdapter);
    
    
        }
    
        private void initData() {
            List<Person> list = new ArrayList<>();
            for (int i = 0; i < 20; i++) {
                Person p = new Person();
                int type = (int) (Math.random() * 3 + 1);
                p.type = type;
                p.content = "content" + 1;
                p.avaterColor = colors[type - 1];
                p.name = "name" + i;
                list.add(p);
            }
            mMyAdapter.addList(list);
            mMyAdapter.notifyDataSetChanged();
        }
    }

    效果如图:

     
    两种布局.png
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  • 原文地址:https://www.cnblogs.com/zhujiabin/p/9288437.html
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