Android实现下拉刷新,上拉加载

川长思鸟来 2023-06-13 06:15 15阅读 0赞

首先，要导入两个依赖（很重要！！！！）  
App——>build gradle——>Sync Now(右上角)

implementation 'com.scwang.smartrefresh:SmartRefreshLayout:1.1.0'  //1.0.5及以前版本的老用户升级需谨慎，API改动过大
     implementation 'com.scwang.smartrefresh:SmartRefreshHeader:1.1.0'  //没有使用特殊Header，可以不加这行

![在这里插入图片描述][20191114162718313.png]  
OK！开始敲代码实现~~~~~~~  
1、新建Activity活动,实现相应逻辑

package com.wmc.loginapplication;
    
    import androidx.appcompat.app.AppCompatActivity;
    import androidx.recyclerview.widget.LinearLayoutManager;
    import androidx.recyclerview.widget.RecyclerView;
    
    import android.os.Bundle;
    
    import com.scwang.smartrefresh.layout.SmartRefreshLayout;
    import com.scwang.smartrefresh.layout.api.RefreshLayout;
    import com.scwang.smartrefresh.layout.constant.SpinnerStyle;
    import com.scwang.smartrefresh.layout.footer.BallPulseFooter;
    import com.scwang.smartrefresh.layout.footer.ClassicsFooter;
    import com.scwang.smartrefresh.layout.header.BezierRadarHeader;
    import com.scwang.smartrefresh.layout.header.ClassicsHeader;
    import com.scwang.smartrefresh.layout.listener.OnLoadMoreListener;
    import com.scwang.smartrefresh.layout.listener.OnRefreshListener;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class RefreshActivity extends AppCompatActivity { 
    
        private SmartRefreshLayout refreshLayout ;//刷新布局
    
        private RecyclerView recyclerView ;//列表布局
    
        private RecyclerViewListDemoAdapter adapter ;//适配器
    
        private List<Entity> data ;//要设置的数据
        @Override
        protected void onCreate(Bundle savedInstanceState) { 
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_refresh);
    
            recyclerView = findViewById(R.id.recyclerView) ;
    
            refreshLayout = findViewById(R.id.refreshLayout);
    
            //设置布局管理器
            recyclerView.setLayoutManager(new LinearLayoutManager(this));
            //设置适配器
            adapter = new RecyclerViewListDemoAdapter(this);
            recyclerView.setAdapter(adapter);
    
            //下拉刷新
            refreshLayout.setRefreshHeader(new ClassicsHeader(this));
            //上拉加载
            refreshLayout.setRefreshFooter(new ClassicsFooter(this));
            //为下来刷新添加事件
            refreshLayout.setOnRefreshListener(new OnRefreshListener() { 
                @Override
                public void onRefresh(RefreshLayout refreshlayout) { 
                    initData();
                    refreshlayout.finishRefresh(2000/*,false*/);//传入false表示刷新失败
                }
            });
            //为上拉下载添加事件
            refreshLayout.setOnLoadMoreListener(new OnLoadMoreListener() { 
                @Override
                public void onLoadMore(RefreshLayout refreshlayout) { 
                    initData();
                    refreshlayout.finishLoadMore(2000/*,false*/);//传入false表示加载失败
                }
            });
        }
        //为每一次刷新添加数据
        private void initData() { 
            data = new ArrayList<>();
            for (int i = 0; i < 5; i++) { 
                Entity entity = new Entity("index" + i);
                data.add(entity);
            }
    
            adapter.addData(data);
        }
    }

2、设置活动布局XML文件

<?xml version="1.0" encoding="utf-8"?>
    <com.scwang.smartrefresh.layout.SmartRefreshLayout 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"
        android:id="@+id/refreshLayout"
        tools:context=".RefreshActivity">
    
    
        <androidx.recyclerview.widget.RecyclerView
    
            android:id="@+id/recyclerView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:overScrollMode="never"
            android:background="#fff" />
    
    </com.scwang.smartrefresh.layout.SmartRefreshLayout>

3、设置适配器

package com.wmc.loginapplication;
    
    import android.content.Context;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;
    import android.widget.Toast;
    
    import androidx.annotation.NonNull;
    import androidx.recyclerview.widget.RecyclerView;
    
    import java.util.ArrayList;
    import java.util.List;
    
    //自定义适配器
    public class RecyclerViewListDemoAdapter extends RecyclerView.Adapter<RecyclerViewListDemoAdapter.ListViewHolder> { 
        private List<Entity> data;
    
        private  Context context ;
    
        private RecyclerViewActivity.OnItemClickListener onItemClickListener;
    
        public RecyclerViewListDemoAdapter(Context context)
        { 
            this.context = context;
        }
    
        public void setOnItemClickListener(RecyclerViewActivity.OnItemClickListener onItemClickListener)
        { 
            this.onItemClickListener = onItemClickListener;
        }
    
        public RecyclerViewListDemoAdapter(List<Entity> data)
        { 
            this.data = data;
        }
    
    
        public void setData(List<Entity> data)
        { 
            this.data = data;
            // 刷新数据
            notifyDataSetChanged();
        }
        //为相应逻辑添加数据
        public void addData(List<Entity> entities)
        { 
            if (data == null)
            { 
                data = new ArrayList<>();
            }
            this.data.addAll(entities);
            notifyDataSetChanged();
        }
    
        /** *创建一个viewHolder并返回 * @param parent 相当于Item存放的容器 * @param viewType 指定布局文件的类型 * @return 返回viewHolder对象 */
        @NonNull
        @Override
        public ListViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { 
            //指定对应的布局文件
           View view =  LayoutInflater.from(parent.getContext()).inflate(R.layout.item_list_demo,parent,false);
            return new ListViewHolder(view);
    
        }
    
        /** * 将数据加载到布局文件的控件上 * @param holder 需要绑定数据的viewHolder * @param position 列表数据的下标 */
        @Override
        public void onBindViewHolder(@NonNull RecyclerViewListDemoAdapter.ListViewHolder holder, final int position) { 
            Entity entity = data.get(position);
            holder.textView.setText(entity.getMsg());
            //将绑定的布局设置点击事件
            holder.textView.setOnClickListener(new View.OnClickListener() { 
                @Override
                public void onClick(View v) { 
                   if(onItemClickListener!=null){ 
                        onItemClickListener.itemClick(position,v);
                   }
                }
            });
        }
        /** *返回数据的大小 * @return */
        @Override
        public int getItemCount() { 
            return data == null ? 0 : data.size();
        }
        //为了系统复用控件
        static class ListViewHolder extends RecyclerView.ViewHolder
        { 
            TextView textView;
    
            public ListViewHolder(@NonNull View itemView)
            { 
                super(itemView);
                // 实例化该控件
                textView = itemView.findViewById(R.id.tv_text);
            }
        }
    }

4、现在所有的逻辑都已经实现了，添加一个Entity实体

package com.wmc.loginapplication;
    
    import android.os.Parcel;
    import android.os.Parcelable;
    
    public class Entity implements Parcelable
    { 
    
        private int count;
    
        private String msg;
    
        public Entity(int count)
        { 
            this.count = count;
        }
    
        public Entity(int count, String msg)
        { 
            this.count = count;
            this.msg = msg;
        }
    
        public Entity(String msg)
        { 
            this.msg = msg;
        }
    
        public int getCount()
        { 
            return count;
        }
    
        public void setCount(int count)
        { 
            this.count = count;
        }
    
        public String getMsg()
        { 
            return msg;
        }
    
        public void setMsg(String msg)
        { 
            this.msg = msg;
        }
    
        @Override
        public int describeContents() {  return 0; }
    
        @Override
        public void writeToParcel(Parcel dest, int flags)
        { 
            dest.writeInt(this.count);
            dest.writeString(this.msg);
        }
    
        protected Entity(Parcel in)
        { 
            this.count = in.readInt();
            this.msg = in.readString();
        }
    
        public static final Parcelable.Creator<Entity> CREATOR = new Parcelable.Creator<Entity>()
        { 
            @Override
            public Entity createFromParcel(Parcel source) { return new Entity(source);}
    
            @Override
            public Entity[] newArray(int size) { return new Entity[size];}
        };
    }

OK，跑起来看看~~~~~~~~

[20191114162718313.png]: https://img-blog.csdnimg.cn/20191114162718313.png