3.11学习总结

今天学习了RecyclerView

build.gradle文件下

//添加RecyclerView 的依赖包
implementation 'androidx.recyclerview:recyclerview-selection:1.1.0'

MainActivity.java

package com.example.recyclerview;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.StaggeredGridLayoutManager;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;

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

public class MainActivity extends AppCompatActivity {
    private List<Bean> data =new ArrayList<>();
    @SuppressLint("MissingInflatedId")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        for (int i = 0; i < 100; i++) {
            if(i%4!=0)
            {
                continue;
            }
            Bean bean = new Bean();
            bean.setName("第" + i + "日学习总结");
            data.add(bean);
        }

         RecyclerView recyclerView = findViewById(R.id.rv);

/*        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(linearLayoutManager);*/

       /* GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 3);
       recyclerView.setLayoutManager(gridLayoutManager);*/

        StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3, LinearLayout.VERTICAL);
        recyclerView.setLayoutManager(staggeredGridLayoutManager);

        MyAdapter myAdapter=new MyAdapter(data,this);
        recyclerView.setAdapter(myAdapter);

        myAdapter.setRecyclerItemClickListener(new MyAdapter.OnRecyclerItemClickListener() {
            @Override
            public void onRecyclerItemClick(int position) {
                
            }
        });
    }
}

Myadapter.java

package com.example.recyclerview;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

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

import java.util.List;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {

    private List<Bean> data;
    private Context context;

    public MyAdapter(List<Bean> data, Context context) {
        this.data = data;
        this.context = context;
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
       View view=View.inflate(context,R.layout.recyclerview_item,null);
        return new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
        holder.tv.setText(data.get(position).getName());
    }

    @Override
    public int getItemCount() {
        return data==null?0:data.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {
        private TextView tv;
        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            tv=itemView.findViewById(R.id.tv);
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if(mOnItemClickListener!=null){
                        mOnItemClickListener.onRecyclerItemClick(getAdapterPosition());
                    }
                }
            });
        }
    }
    private OnRecyclerItemClickListener mOnItemClickListener;
    public void setRecyclerItemClickListener(OnRecyclerItemClickListener listener){
        mOnItemClickListener=listener;
    }
    public interface OnRecyclerItemClickListener{
        void onRecyclerItemClick(int position);
    }
}

Bean.java

package com.example.recyclerview;

public class Bean
{
    String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

main.xml

<?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:orientation="vertical">

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

    </androidx.recyclerview.widget.RecyclerView>


</LinearLayout>

item.xml

<?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:orientation="vertical">
    <TextView
        android:id="@+id/tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        >

    </TextView>

</LinearLayout>