优雅的使用RecyclerView(在一个recyclerView里显示有不同子布局的界面，就是混合不同布局)

清疚 2022-07-15 02:17 214阅读 0赞

[原文][Link 1]

一：为了使用RecyclerView，首先在build.gradle(Module:app)文件里：

加入：

dependencies {
      compile 'com.android.support:recyclerview-v7:24.0.0' }

二：主要代码

package com.example.kirito.testrecyclerview;
    
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.support.v7.widget.LinearLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.util.Log;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class MainActivity extends AppCompatActivity {
        private RecyclerView recyclerView;
        private DemoAdapter adpter;
    
        private int colors[] = {android.R.color.holo_blue_bright,android.R.color.black,android.R.color.holo_red_dark};
        private static final String TAG = "MainActivity";
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
            //必须设置layoutmanager，否则无法正常加载
            recyclerView.setLayoutManager(new LinearLayoutManager(this,
                    LinearLayoutManager.VERTICAL,false));
            adpter = new DemoAdapter(this);
            recyclerView.setAdapter(adpter);
            initData();
        }
    
        private void initData() {
            List<Item> items = new ArrayList<>();
            for (int i = 0; i < 20; i++) {
                Item item = new Item();
                //产生1-3的随机数
                int type = (int) (Math.random() * 3 + 1);
                //Log.e(TAG, "initData: random---"+ (int) (Math.random() * 3 + 1));
                item.type = type;
                item.avaterColor = colors[type - 1];
                item.content = "content:" + i;
                item.contentColor = colors[type - 1];
                item.name = "name:" + i;
                items.add(item);
            }
            adpter.addList(items);
            //即使不要下面这句也能正常初始化recyclerview
            adpter.notifyDataSetChanged();
        }
    
    
    }
    
     package com.example.kirito.testrecyclerview;
    
    import android.support.v7.widget.RecyclerView;
    import android.view.View;
    
    /**
     * Created by kirito on 2016.10.29.
     */
    
    public abstract class TypeAbstarctViewHolder extends RecyclerView.ViewHolder {
        public TypeAbstarctViewHolder(View itemView) {
            super(itemView);
        }
    
        public abstract void bindHolder(Item item);
    }
    
     package com.example.kirito.testrecyclerview;
    
    import android.support.v7.widget.RecyclerView;
    import android.view.View;
    import android.widget.ImageView;
    import android.widget.TextView;
    
    /**
     * Created by kirito on 2016.10.29.
     */
    
    public class TypeOneHolder extends TypeAbstarctViewHolder {
        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(Item item) {
            avater.setBackgroundResource(item.avaterColor);
            name.setText(item.name);
        }
    }
    
     package com.example.kirito.testrecyclerview;
    
    import android.view.View;
    import android.widget.ImageView;
    import android.widget.TextView;
    
    /**
     * Created by kirito on 2016.10.29.
     */
    
    public class TypeTwoHolder extends TypeAbstarctViewHolder {
        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);
        }
    
        @Override
        public void bindHolder(Item item) {
            avater.setBackgroundResource(item.avaterColor);
            name.setText(item.name);
            content.setText(item.content);
        }
    }
    
     package com.example.kirito.testrecyclerview;
    
    import android.view.View;
    import android.widget.ImageView;
    import android.widget.TextView;
    
    /**
     * Created by kirito on 2016.10.29.
     */
    
    public class TypeThreeHolder extends TypeAbstarctViewHolder {
        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);
        }
    
        @Override
        public void bindHolder(Item item) {
            avater.setBackgroundResource(item.avaterColor);
            name.setText(item.name);
            content.setText(item.content);
            iv.setBackgroundResource(item.contentColor);
        }
    }
    
     package com.example.kirito.testrecyclerview;
    
    import android.content.Context;
    import android.support.v7.widget.RecyclerView;
    import android.view.LayoutInflater;
    import android.view.ViewGroup;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /**
     * Created by kirito on 2016.10.29.
     */
    
    public class DemoAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
        private List<Item> itemList = new ArrayList<>();
        private LayoutInflater mLayoutInflater;
    
        public DemoAdapter(Context context) {
            mLayoutInflater = LayoutInflater.from(context);
        }
    
        //使用此方法从mainactivity获取数据,这样就不用从构造方法里传数据了
        public void addList(List<Item> items){
            itemList.addAll(items);
        }
    
        @Override
        public int getItemViewType(int position) {
            return itemList.get(position).type;
        }
    
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            //根据不同的viewType，创建并返回相应的ViewHolder
            switch (viewType){
                case Item.TYPE_ONE:
                    return new TypeOneHolder(mLayoutInflater.inflate(R.layout.item_type_one,parent,false));
                case Item.TYPE_TWO:
                    return new TypeTwoHolder(mLayoutInflater.inflate(R.layout.item_type_two,parent,false));
                case Item.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) {
            //因为抽象出了TypeAbstarctViewHolder，所以这里可以减少代码量
            ((TypeAbstarctViewHolder)holder).bindHolder(itemList.get(position));
        }
    
        @Override
        public int getItemCount() {
            return itemList.size();
        }
    }
    
     package com.example.kirito.testrecyclerview;
    
    /**
     * Created by kirito on 2016.10.29.
     */
    
    public class Item {
        protected static final int TYPE_ONE = 1;
        protected static final int TYPE_TWO = 2;
        protected 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;
        }
    }
    
    布局文件代码就省略了...

运行效果：

三：混合Grid布局

主要修改了MainActivity里的代码，如下

package com.example.kirito.testrecyclerview;
    
    import android.graphics.Rect;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.support.v7.widget.GridLayoutManager;
    import android.support.v7.widget.LinearLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.util.Log;
    import android.view.View;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class MainActivity extends AppCompatActivity {
        private RecyclerView recyclerView;
        private DemoAdapter adpter;
    
        private int colors[] = {android.R.color.holo_blue_bright,android.R.color.black,android.R.color.holo_red_dark};
        private static final String TAG = "MainActivity";
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
            //gridlayoutmanager构造参数里的2，指的是一行有几列
            final GridLayoutManager manager = new GridLayoutManager(this,2);
            //必须设置layoutmanager，否则无法正常加载
            recyclerView.setLayoutManager(manager);
            adpter = new DemoAdapter(this);
            recyclerView.setAdapter(adpter);
            //设置占用的列数
            manager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
                @Override
                public int getSpanSize(int position) {
                    int type = recyclerView.getAdapter().getItemViewType(position);
                    //若是TYPE_THREE，占用两列，否则占用一列
                    if (type == Item.TYPE_THREE){
                        return manager.getSpanCount();
                    }else {
                        return 1;
                    }
                }
            });
            recyclerView.addItemDecoration(new RecyclerView.ItemDecoration() {
                @Override
                public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
                    //给布局里的子view添加边距
                    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 = 10;
                        }else {
                            outRect.left = 10;
                        }
                    }
                }
            });
            initData();
        }
    
        private void initData() {
            List<Item> items = new ArrayList<>();
            for (int i = 0; i < 20; i++) {
                Item item = new Item();
                //产生1-3的随机数
                int type = (int) (Math.random() * 3 + 1);
                //Log.e(TAG, "initData: random---"+ (int) (Math.random() * 3 + 1));
                item.type = type;
                item.avaterColor = colors[type - 1];
                item.content = "content:" + type;
                item.contentColor = colors[type - 1];
                item.name = "name:" + type;
                items.add(item);
            }
            adpter.addList(items);
            //即使不要下面这句也能正常初始化recyclerview
            adpter.notifyDataSetChanged();
        }
    
    
    }
    
    效果图：

完整的代码：github

[Link 1]: http://www.imooc.com/video/13042