Android Studio RecyclerVIew的基本使用

Android Studio RecyclerVIew的基本使用

本博客主要讲述RecyclerView的四种基本使用方法：纵向列表视图、横向列表视图、网格视图、瀑布流视图，并且对他们实现一些拓展效果。

本文主要是对纵向列表视图进行一步一步的详细讲解，比较接近的横向列表视图、网格视图、瀑布流视图等提供了源码。

比较适合刚刚入门的小白查看

1.添加依赖

在project下的build.gradle下添加语句,如果有新版本，按照提示修改版本数字即可，此版本当前为最新版本，并点击右上角的跳出的提醒的 sync now

implementation 'androidx.recyclerview:recyclerview:1.1.0'

2.新建recyclerview的Activity文件

public class RecycleViewActivity extends AppCompatActivity {
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_recycle_view);
    }

}

3.设置recyclervIew的layout文件

这里有四个功能，所以有四个按钮，跳转到新的界面，大家可以一个一个按钮添加，我这里就不重复展示了，直接放了完整代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="15dp"
    android:orientation="vertical">

    <Button
        android:id="@+id/BBTTNN01"
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:text="列表视图"
        android:textSize="40sp"
        android:textColor="@color/white"
        android:background="@color/teal_700"
        />
    <Button
        android:id="@+id/BBTTNN02"
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:text="水平滚动"
        android:textSize="40sp"
        android:textColor="@color/white"
        android:background="@color/teal_700"
        />
    <Button
        android:id="@+id/BBTTNN03"
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:text="网格视图"
        android:textSize="40sp"
        android:textColor="@color/white"
        android:background="@color/teal_700"
        />
    <Button
        android:id="@+id/BBTTNN04"
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:text="瀑布流"
        android:textSize="40sp"
        android:textColor="@color/white"
        android:background="@color/teal_700"
        />
</LinearLayout>

5.设置recyclerview的activity文件让四个按钮分别跳转到四个功能的界面

public class RecycleViewActivity extends AppCompatActivity {
    
    

    private Button BT01_rec;
    private Button BT02_rec;
    private Button BT03_rec;
    private Button BT04_rec;

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

        BT01_rec=findViewById(R.id.BBTTNN01);

        BT01_rec.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                Intent intent=new Intent(RecycleViewActivity.this,LinearRecyclerActivity.class);
                startActivity(intent);
            }
        });
        BT02_rec=findViewById(R.id.BBTTNN02);
        BT02_rec.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                Intent intent=new Intent(RecycleViewActivity.this,HorRecycActivity.class);
                startActivity(intent);
            }
        });

        BT03_rec=findViewById(R.id.BBTTNN03);
        BT03_rec.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                Intent intent=new Intent(RecycleViewActivity.this,GrideRActivity.class);
                startActivity(intent);
            }
        });
        BT04_rec=findViewById(R.id.BBTTNN04);
        BT04_rec.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                Intent intent=new Intent(RecycleViewActivity.this,PUBUrecActivity.class);
                startActivity(intent);
            }
        });


    }

}

6.接下来开始实现第一个功能：纵向列表视图

（1）新建Activity文件，命名LinearRecyclerActivity

public class LinearRecyclerActivity extends AppCompatActivity {
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_linear_layout); //这个R可能会报红，根据系统提示修改即可
    }
}

（2）来到activity_linear_layout文件，新建一个整体上的recycrview的layout

<?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">
    
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"       
        android:background="@color/gray"
        />

</RelativeLayout>

注意android:layout_height=“wrap_content” 设置成wrap_content，不要设置成match_parent，不然间距会非常大，有兴趣的朋友可以设置一下体验一下。

（3）回到LinearRecyclerActivity，新建一个实例

public class LinearRecyclerActivity extends AppCompatActivity {
    
    
    private RecyclerView mrv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_linear_layout);
        mrv=findViewById(R.id.rv_main);
    }
}

（4）接下来设置视图的方向：横向或者纵向

加入以下语句到LinearRecyclerActivity

LinearLayoutManager layoutManager=new LinearLayoutManager(this);
layoutManager.setOrientation(RecyclerView.VERTICAL); //VERTICAL指设置成纵向
mrv.setLayoutManager(layoutManager);

加了之后的代码

public class LinearRecyclerActivity extends AppCompatActivity {
    
    
    private RecyclerView mrv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_linear_layout);
        mrv=findViewById(R.id.rv_main);
        LinearLayoutManager layoutManager=new LinearLayoutManager(this);
        layoutManager.setOrientation(RecyclerView.VERTICAL);
        mrv.setLayoutManager(layoutManager);
    }
}

（5）现在要写一下每一个recyclerview每一个子元素的样式

新建一个layout文件命名为 layout_linear_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/white"
    android:paddingLeft="20dp"
    android:paddingRight="20dp"
    android:paddingTop="10dp"
    android:paddingBottom="10dp"
    >
    <ImageView
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:id="@+id/iv_re01"
        android:layout_gravity="center_horizontal"
        android:background="@color/teal_700"

        />
    <TextView
        android:paddingLeft="20dp"
        android:paddingTop="20dp"
        android:id="@+id/tv_re01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/teal_700"
        android:textSize="20sp"
        android:text="Fruit"
        android:layout_gravity="center_horizontal"

        />
</LinearLayout>

（6）接下来我们要为这个实例写一个适配器，添加它的默认效果

新建一个java class 命名LinearAdapter，继承于RecyclerView.Adapter，泛型<LinearAdapter.LinearViewHolder>

public class LinearAdapter extends RecyclerView.Adapter<LinearAdapter.LinearViewHolder> {
    
    
    private Context wcontext;

    public LinearAdapter(Context context){
    
    
        this.wcontext=context;
    }


     class LinearViewHolder extends RecyclerView.ViewHolder{
    
    
        private TextView textView;
        private ImageView imageView;

        public LinearViewHolder(@NonNull View itemView) {
    
    
            super(itemView);
						//找到我们刚刚设置的子元素的效果中的两个控件			
            textView=itemView.findViewById(R.id.tv_re01);
            imageView=itemView.findViewById(R.id.iv_re01);

        }

    }
    @NonNull
    @Override
    public LinearViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    
    

        return new LinearViewHolder(LayoutInflater.from(wcontext).inflate(R.layout.layout_linear_item, parent, false));
    }

    @Override
    public void onBindViewHolder(@NonNull LinearAdapter.LinearViewHolder holder, int position) {
    
    
        holder.textView.setText("Hello");             //设置需要显示的文字
        holder.imageView.setImageResource(R.drawable.fruit01); //设置需要显示的图片
    }

    @Override
    public int getItemCount() {
    
    
        return 30;                          //设置子元素的数量 ,这里设置成三十个，你也可以设置成其他数字
    }
}

（7）回到LinearRecyclerActivity，应用刚刚写的适配器

public class LinearRecyclerActivity extends AppCompatActivity {
    
    

    private RecyclerView mrv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_linear_layout);
        mrv=findViewById(R.id.rv_main);
        LinearLayoutManager layoutManager=new LinearLayoutManager(this);
        layoutManager.setOrientation(RecyclerView.VERTICAL);
        mrv.setLayoutManager(layoutManager);
        mrv.setAdapter(new LinearAdapter(LinearRecyclerActivity.this));

    }
}

可以运行了！

（8）我们的recyclerview已经成功运行，接下来我们为它添加点击的效果（监听事件），目标实现轻点后和长按后弹出不同的Toast效果

来到LinearAdapter
首先声明

private OnItemClickListener wlistener;
private OnItemLongClickListener wwlistener;

然后修改public LinearAdapter，要添加点击事件

public LinearAdapter(Context context, OnItemClickListener wlistener,OnItemLongClickListener wwlistener){
    
    
    this.wlistener=wlistener;
    this.wcontext=context;
    this.wwlistener=wwlistener;
}

然后修改public void onBindViewHolder，同样添加点击效果

    @Override
    public void onBindViewHolder(@NonNull LinearAdapter.LinearViewHolder holder, int position) {
    
    
        holder.textView.setText("Hello");             //设置需要显示的文字
        holder.imageView.setImageResource(R.drawable.fruit01); //设置需要显示的图片
				holder.itemView.setOnClickListener(new View.OnClickListener() {
    
                 //轻点
            @Override
            public void onClick(View v) {
    
    
                wlistener.onClick(position);

            }
        });
		        holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
    
       //长按
            @Override
            public boolean onLongClick(View v) {
    
    
                wwlistener.onLongClick(position);
                return true;
            }
        });
    }

新建两个接口，分别给click和longclick

public interface OnItemClickListener {
    
    
        void onClick(int pos);
    }

    public interface OnItemLongClickListener {
    
    
        void onLongClick(int pos);
    }

完整的LinearAdapter代码如下

public class LinearAdapter extends RecyclerView.Adapter<LinearAdapter.LinearViewHolder> {
    
    
    private Context wcontext;
    private OnItemClickListener wlistener;
    private OnItemLongClickListener wwlistener;


    public LinearAdapter(Context context, OnItemClickListener wlistener,OnItemLongClickListener wwlistener){
    
    
    this.wlistener=wlistener;
    this.wcontext=context;
    this.wwlistener=wwlistener;
     }

     class LinearViewHolder extends RecyclerView.ViewHolder{
    
    
        private TextView textView;
        private ImageView imageView;

        public LinearViewHolder(@NonNull View itemView) {
    
    
            super(itemView);
						//找到我们刚刚设置的子元素的效果中的两个控件			
            textView=itemView.findViewById(R.id.tv_re01);
            imageView=itemView.findViewById(R.id.iv_re01);

        }

    }
    @NonNull
    @Override
    public LinearViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    
    

        return new LinearViewHolder(LayoutInflater.from(wcontext).inflate(R.layout.layout_linear_item, parent, false));
    }

    @Override
    public void onBindViewHolder(@NonNull LinearAdapter.LinearViewHolder holder, int position) {
    
    
        holder.textView.setText("Hello");             //设置需要显示的文字
        holder.imageView.setImageResource(R.drawable.fruit01); //设置需要显示的图片
				holder.itemView.setOnClickListener(new View.OnClickListener() {
    
                 //轻点
            @Override
            public void onClick(View v) {
    
    
                wlistener.onClick(position);

            }
        });
		        holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
    
       //长按
            @Override
            public boolean onLongClick(View v) {
    
    
                wwlistener.onLongClick(position);
                return true;
            }
        });
    }
    @Override
    public int getItemCount() {
    
    
        return 30;                          //设置子元素的数量 ,这里设置成三十个，你也可以设置成其他数字
    }

		public interface OnItemClickListener {
    
    
        void onClick(int pos);
    }

    public interface OnItemLongClickListener {
    
    
        void onLongClick(int pos);
    }
}

（9）回到LinearRecyclerActivity，重新应用刚刚写的适配器

public class LinearRecyclerActivity extends AppCompatActivity {
    
    

    private RecyclerView mrv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_linear_layout);
        mrv=findViewById(R.id.rv_main);
        LinearLayoutManager layoutManager=new LinearLayoutManager(this);
        layoutManager.setOrientation(RecyclerView.VERTICAL);
        mrv.setLayoutManager(layoutManager);
        
        mrv.setAdapter(new LinearAdapter(LinearRecyclerActivity.this, new LinearAdapter.OnItemClickListener() {
    
    
            @Override
            public void onClick(int pos) {
    
    
                Toast.makeText(LinearRecyclerActivity.this, "click" + pos, Toast.LENGTH_SHORT).show();
            }
        }, new LinearAdapter.OnItemLongClickListener() {
    
    
            @Override
            public void onLongClick(int pos) {
    
    
                Toast.makeText(LinearRecyclerActivity.this, "Longclick" + pos, Toast.LENGTH_SHORT).show();
            }
        }
		   	));

    }
	}

（10）运行，尝试长按子元素和点击子元素，会出现不同的效果

（11）我们发现子元素之间的边界不是很明显，我们为我们的子元素之间添加边界

在values文件夹下新建文件dimens.xml
内容如下

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <dimen name="dividerHeigh" >2dp</dimen>
</resources>

来到LinearRecyclerActivity，新建Java类，class Mydecoration，继承于RecyclerView.ItemDecoration

class  Mydecoration extends  RecyclerView.ItemDecoration{
    
    
        @Override
        public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
    
    
            super.getItemOffsets(outRect, view, parent, state);
            outRect.set(0,0,0,getResources().getDimensionPixelOffset(R.dimen.dividerHeigh));
        }
    }

并在 protected void onCreate(Bundle savedInstanceState)中添加以下语句

mrv.addItemDecoration(new Mydecoration());

完整的LinearRecyclerActivity代码如下

public class LinearRecyclerActivity extends AppCompatActivity {
    
    

    private RecyclerView mrv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_linear_layout);
        mrv=findViewById(R.id.rv_main);
        LinearLayoutManager layoutManager=new LinearLayoutManager(this);
        layoutManager.setOrientation(RecyclerView.VERTICAL);
        mrv.setLayoutManager(layoutManager);
        
        mrv.setAdapter(new LinearAdapter(LinearRecyclerActivity.this, new LinearAdapter.OnItemClickListener() {
    
    
            @Override
            public void onClick(int pos) {
    
    
                Toast.makeText(LinearRecyclerActivity.this, "click" + pos, Toast.LENGTH_SHORT).show();
            }
        }, new LinearAdapter.OnItemLongClickListener() {
    
    
            @Override
            public void onLongClick(int pos) {
    
    
                Toast.makeText(LinearRecyclerActivity.this, "Longclick" + pos, Toast.LENGTH_SHORT).show();
            }
        }
		   	));
				mrv.addItemDecoration(new Mydecoration());

    }
		class  Mydecoration extends  RecyclerView.ItemDecoration{
    
    
        @Override
        public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
    
    
            super.getItemOffsets(outRect, view, parent, state);
            outRect.set(0,0,0,getResources().getDimensionPixelOffset(R.dimen.dividerHeigh));
        }
    }
	}

运行查看效果，子元素之间已经添加好效果，当然这个效果耶可以通过margin来实现，这里也不多说了

7.我们来实现横向列表视图

按照横向视图一模一样的方法建立,将HorRecyclerActivity中的以下语句

layoutManager.setOrientation(RecyclerView.VERTICAL);

修改为

layoutManager.setOrientation(RecyclerView.HORIZONTAL);

注意hor_linear_recycler_item的子元素的layout文件，可以设置成这样的形式，放上我的代码提供参考

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="200dp"
    android:background="@color/white"
    android:paddingLeft="20dp"
    android:paddingRight="20dp"
    android:paddingTop="10dp"
    android:paddingBottom="10dp"
    >
    <ImageView
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:id="@+id/iv_hor_re01"
        android:layout_gravity="center_horizontal"
        android:background="@color/teal_700"

        />
    <TextView
        android:paddingLeft="20dp"
        android:paddingTop="20dp"
        android:id="@+id/tv_hor_re01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/teal_700"
        android:textSize="20sp"
        android:text="Fruit"
        android:layout_gravity="center_horizontal"

        />

</LinearLayout>

8.实现网格视图

activity文件

public class GrideRActivity extends AppCompatActivity {
    
    

    private RecyclerView recvg;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gride_r);
        recvg = findViewById(R.id.grv);
        recvg.setLayoutManager(new GridLayoutManager(GrideRActivity.this,3));
        recvg.setAdapter(new GrideViewRecAdapter(GrideRActivity.this,new GrideViewRecAdapter.OnItemClickListener(){
    
    

            @Override
            public void onClick(int pos) {
    
    
                Toast.makeText(GrideRActivity.this,"click"+pos,Toast.LENGTH_SHORT).show();
            }
        },new GrideViewRecAdapter.OnItemLongClickListener(){
    
    

            @Override
            public void onLongClick(int pos) {
    
    
                Toast.makeText(GrideRActivity.this,"Longclick"+pos,Toast.LENGTH_SHORT).show();
            }
        }));

        recvg.addItemDecoration(new Mydecoration());
    }
    class Mydecoration extends RecyclerView.ItemDecoration{
    
    
        @Override
        public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
    
    
            super.getItemOffsets(outRect, view, parent, state);
            outRect.set(getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh));
        }
    }
}

adapter文件

public class GrideViewRecAdapter extends RecyclerView.Adapter<GrideViewRecAdapter.LinearViewHolder> {
    
    


    private Context mcontext;
    private OnItemClickListener mlistener;
    private OnItemLongClickListener mylistener;

    public GrideViewRecAdapter(Context context, OnItemClickListener mlistener, OnItemLongClickListener mylistener){
    
    
        this.mlistener=mlistener;
        this.mcontext=context;
        this.mylistener=mylistener;
    }
    @NonNull
    @Override
    public LinearViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    
    
        return new LinearViewHolder(LayoutInflater.from(mcontext).inflate(R.layout.layout_griderecview_item,parent,false));
    }

    @Override
    public void onBindViewHolder(@NonNull LinearViewHolder holder, int position) {
    
    
        holder.textView.setText("Hello World!");
        holder.imageView.setImageResource(R.drawable.fruit01);
        holder.itemView.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                mlistener.onClick(position);

            }
        });
        holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
    
    
            @Override
            public boolean onLongClick(View v) {
    
    
                mylistener.onLongClick(position);
                return true;
            }
        });

    }

    @Override
    public int getItemCount() {
    
    
        return 30;
    }

    class LinearViewHolder extends RecyclerView.ViewHolder{
    
    
        private TextView textView;
        private ImageView imageView;


        public LinearViewHolder(@NonNull View itemView) {
    
    

            super(itemView);

            textView=itemView.findViewById(R.id.tv_grc_re01);
            imageView=itemView.findViewById(R.id.iv_grc_re01);
        }

    }


    public interface OnItemClickListener {
    
    
        void onClick(int pos);
    }

    public interface OnItemLongClickListener {
    
    
        void onLongClick(int pos);
    }
}

layout文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    >
    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/grv"
        android:background="@color/gray"
        />

</LinearLayout>

item的layout文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@color/white"
    android:paddingLeft="20dp"
    android:paddingRight="20dp"
    android:paddingTop="10dp"
    android:paddingBottom="10dp"
    >
    <ImageView
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:id="@+id/iv_grc_re01"
        android:layout_gravity="center_horizontal"
        android:background="@color/teal_700"

        />
    <TextView
        android:paddingLeft="20dp"
        android:paddingTop="20dp"
        android:id="@+id/tv_grc_re01"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:textColor="@color/teal_700"

        android:text="Fruit"
        />

</LinearLayout>

9.瀑布流

activity

public class PUBUrecActivity extends AppCompatActivity {
    
    

    private RecyclerView repb;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_p_u_b_urec);
        repb=findViewById(R.id.re_pb);
        repb.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL));
        repb.setAdapter(new StaggeredGrideViewRecAdapter(PUBUrecActivity.this, new StaggeredGrideViewRecAdapter.OnItemClickListener() {
    
    
            @Override
            public void onClick(int pos) {
    
    
                Toast.makeText(PUBUrecActivity.this,"click:"+pos,Toast.LENGTH_SHORT).show();
            }
        }));


        repb.addItemDecoration(new Mydecoration());
    }
    class  Mydecoration extends  RecyclerView.ItemDecoration{
    
    
        @Override
        public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
    
    
            super.getItemOffsets(outRect, view, parent, state);
            outRect.set(getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh));
        }
    }
}

adapter文件

public class StaggeredGrideViewRecAdapter extends RecyclerView.Adapter<StaggeredGrideViewRecAdapter.LinearViewHolder> {
    
    


    private Context mcontext;
    private OnItemClickListener mlistener;


    public StaggeredGrideViewRecAdapter(Context context, OnItemClickListener mlistener){
    
    
        this.mlistener=mlistener;
        this.mcontext=context;

    }
    @NonNull
    @Override
    public LinearViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    
    
        return new LinearViewHolder(LayoutInflater.from(mcontext).inflate(R.layout.layout_staggeredgride_item,parent,false));
    }

    @Override
    public void onBindViewHolder(@NonNull LinearViewHolder holder, int position) {
    
    
        if(position %2==0)

        {
    
    
            holder.imageView.setImageResource(R.drawable.fruit04);
        }
        else if (position % 2 == 1)
        {
    
    
            holder.imageView.setImageResource(R.drawable.fruit05);
        }


        holder.itemView.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                mlistener.onClick(position);

            }
        });


    }

    @Override
    public int getItemCount() {
    
    
        return 50;
    }

    class LinearViewHolder extends RecyclerView.ViewHolder{
    
    

        private ImageView imageView;


        public LinearViewHolder(@NonNull View itemView) {
    
    

            super(itemView);

            imageView=itemView.findViewById(R.id.sta_gv_img);
        }

    }


    public interface OnItemClickListener {
    
    
        void onClick(int pos);
    }

}

瀑布流的layout文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/re_pb"
        android:background="@color/gray"
        />

</LinearLayout>

item的layout文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"

    >


    <ImageView

        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/sta_gv_img"
        android:scaleType="fitCenter"
        android:background="@color/white"

        />


</LinearLayout>

9.实现交替的列表视图

想要实现这样的交替列表视图？

下面提供源码

activity文件

package com.example.androidlearning.recyclerview;

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

import android.graphics.Rect;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import com.example.androidlearning.R;

public class LinearRecyclerActivity extends AppCompatActivity {
    
    


    private RecyclerView mrv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_linear_layout);
        mrv=findViewById(R.id.rv_main);
        LinearLayoutManager layoutManager=new LinearLayoutManager(this);
        layoutManager.setOrientation(RecyclerView.VERTICAL);
        mrv.setLayoutManager(layoutManager);

        mrv.setAdapter(new LinearAdapter(LinearRecyclerActivity.this, new LinearAdapter.OnItemClickListener() {
    
    
            @Override
            public void onClick(int pos) {
    
    
                Toast.makeText(LinearRecyclerActivity.this, "click" + pos, Toast.LENGTH_SHORT).show();
            }
        }, new LinearAdapter.OnItemLongClickListener() {
    
    
            @Override
            public void onLongClick(int pos) {
    
    
                Toast.makeText(LinearRecyclerActivity.this, "Longclick" + pos, Toast.LENGTH_SHORT).show();
            }
        }


        ));
        mrv.addItemDecoration(new Mydecoration());

    }

    class  Mydecoration extends  RecyclerView.ItemDecoration{
    
    
        @Override
        public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
    
    
            super.getItemOffsets(outRect, view, parent, state);
            outRect.set(getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh),getResources().getDimensionPixelOffset(R.dimen.dividerHeigh));
        }
    }
}

adapter文件

package com.example.androidlearning.recyclerview;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.example.androidlearning.R;
public class LinearAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    
    


    private Context mcontext;
    private OnItemClickListener mlistener;
    private OnItemLongClickListener mylistener;

    public LinearAdapter(Context context,OnItemClickListener mlistener, OnItemLongClickListener mylistener){
    
    
        this.mlistener=mlistener;
        this.mcontext=context;
        this.mylistener=mylistener;
    }
    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    
    
        if(viewType==0){
    
    
            return new LinearViewHolder(LayoutInflater.from(mcontext).inflate(R.layout.layout_linear_item,parent,false));
        }
        else
        {
    
    
            return new LinearViewHolder2(LayoutInflater.from(mcontext).inflate(R.layout.layout_linear_item_2,parent,false));
        }


    }

    @Override
    public int getItemViewType(int position) {
    
    
        if(position % 2 ==0)
        {
    
    
            return 0;
        }
        else
        {
    
    
            return  1;
        }
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
    
    
        if(getItemViewType(position)==0)
        {
    
    
            ((LinearViewHolder)holder).textView.setText("Hello World!");
            ((LinearViewHolder)holder).imageView.setImageResource(R.drawable.fruit01);
            ((LinearViewHolder)holder).itemView.setOnClickListener(new View.OnClickListener() {
    
    
                @Override
                public void onClick(View v) {
    
    
                    mlistener.onClick(position);

                }
            });
            ((LinearViewHolder)holder).itemView.setOnLongClickListener(new View.OnLongClickListener() {
    
    
                @Override
                public boolean onLongClick(View v) {
    
    
                    mylistener.onLongClick(position);
                    return true;
                }
            });
        }
        else
        {
    
    
            ((LinearViewHolder2)holder).textView.setText("Hello World!");

            ((LinearViewHolder2)holder).itemView.setOnClickListener(new View.OnClickListener() {
    
    
                @Override
                public void onClick(View v) {
    
    
                    mlistener.onClick(position);

                }
            });
            ((LinearViewHolder2)holder).itemView.setOnLongClickListener(new View.OnLongClickListener() {
    
    
                @Override
                public boolean onLongClick(View v) {
    
    
                    mylistener.onLongClick(position);
                    return true;
                }
            });
        }

    }

    @Override
    public int getItemCount() {
    
    
        return 30;
    }

    class LinearViewHolder extends RecyclerView.ViewHolder{
    
    
        private TextView textView;
        private ImageView imageView;


        public LinearViewHolder(@NonNull View itemView) {
    
    

            super(itemView);

            textView=itemView.findViewById(R.id.tv_re01);
            imageView=itemView.findViewById(R.id.iv_re01);
        }

    }
    class LinearViewHolder2 extends RecyclerView.ViewHolder{
    
    
        private TextView textView;



        public LinearViewHolder2(@NonNull View itemView) {
    
    

            super(itemView);

            textView=itemView.findViewById(R.id.xtv_re01);

        }

    }

    public interface OnItemClickListener {
    
    
        void onClick(int pos);
    }

    public interface OnItemLongClickListener {
    
    
        void onLongClick(int pos);
    }
}

layout文件

<?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">
    
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/gray"
        />

</RelativeLayout>

item-1 layout文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/white"
    android:paddingLeft="20dp"
    android:paddingRight="20dp"
    android:paddingTop="10dp"
    android:paddingBottom="10dp"
    >
    <ImageView
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:id="@+id/iv_re01"
        android:layout_gravity="center_horizontal"
        android:background="@color/teal_700"

        />
    <TextView
        android:paddingLeft="20dp"
        android:paddingTop="20dp"
        android:id="@+id/tv_re01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/teal_700"
        android:textSize="20sp"
        android:text="Fruit"
        android:layout_gravity="center_horizontal"

        />

</LinearLayout>

item-2的layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/white"
    android:paddingLeft="20dp"
    android:paddingRight="20dp"
    android:paddingTop="10dp"
    android:paddingBottom="10dp"
    >

    <TextView
        android:paddingLeft="20dp"
        android:paddingTop="20dp"
        android:id="@+id/xtv_re01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/teal_700"
        android:textSize="20sp"
        android:text="Fruit"
        android:layout_gravity="center_horizontal"

        />

</LinearLayout>