第一行代码 -3-2 软件也要拼脸蛋-UI界面-更强大的滚动条-RecyclerView

2022-10-11 08:36:15

简述教程：https://www.jianshu.com/p/4fc6164e4709

一基础准备

1 添加RecyclerView控件引用库文件

2 总布局添加RecyclerView控件

3 RecyclerView控件设置子控件fruit_item.xml（每一个小单元）

4设置特定实体类（水果类）

5创建适配器

5.1 修改引用实体类

5.2 布局初始化加入子控件fruit_item.xml

5.3获取子控件中的各个控件ID+设置按键动作

5.4获取当前位置（水果）实例信息（名称+图片ID），赋予子控件的各个ID

二开始使用

1 特定类实例化-赋值

2 特定类实例化-存放在list中

3 创建

 applicationId "com.example.recyclerviewtest"

compile 'com.android.support:appcompat-v7:25.3.1'

compile 'com.android.support:recyclerview-v7:25.3.1'

同步一下：

布局添加：

 <android.support.v7.widget.RecyclerView

        android:id="@_id/recycler_view"

        android:layout_width="match_parent"

        android:layout_height="match_parent"/>

子布局 fruit_item.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"

    android:layout_width="match_parent"

    android:layout_height="wrap_content"

    android:layout_margin="5dp" >

    <ImageView

        android:id="@+id/fruit_image"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_gravity="center_horizontal" />

    <TextView

        android:id="@+id/fruit_name"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_gravity="left"

        android:layout_marginTop="10dp" />

</LinearLayout>

填充内容-Fruit类

package com.espressif.activitytest;

public class Fruit {

    private String name;

    private int imageId;

    public Fruit(String name, int imageId) {

        this.name = name;

        this.imageId = imageId;

    }

    public String getName() {

        return name;

    }

    public int getImageId() {

        return imageId;

    }

}

下面代码多了按键动作

package com.espressif.activitytest;

/**

 * Created by dongdong on 2018/6/18.

 */

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ImageView;

import android.widget.TextView;

import android.widget.Toast;

import java.util.ArrayList;

import java.util.List;

public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder>{

    private List<Fruit> mFruitList;

    private List<Fruit> fruitList = new ArrayList<Fruit>();

    static class ViewHolder extends RecyclerView.ViewHolder {

        View fruitView;

        ImageView fruitImage;

        TextView fruitName;

        public ViewHolder(View view) {

            super(view);

            fruitView = view;

            fruitImage = (ImageView) view.findViewById(R.id.fruit_image);

            fruitName = (TextView) view.findViewById(R.id.fruit_name);

        }

    }

    public FruitAdapter(List<Fruit> fruitList) {

        mFruitList = fruitList;

    }

    @Override

    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item, parent, false);

        final ViewHolder holder = new ViewHolder(view);

        holder.fruitView.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                int position = holder.getAdapterPosition();

                Fruit fruit = mFruitList.get(position);

                Toast.makeText(v.getContext(), "you clicked view " + fruit.getName(), Toast.LENGTH_SHORT).show();

            }

        });

        holder.fruitImage.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                int position = holder.getAdapterPosition();

                Fruit fruit = mFruitList.get(position);

                Toast.makeText(v.getContext(), "you clicked image " + fruit.getName(), Toast.LENGTH_SHORT).show();

            }

        });

        return holder;

    }

    @Override

    public void onBindViewHolder(ViewHolder holder, int position) {

        Fruit fruit = mFruitList.get(position);

        holder.fruitImage.setImageResource(fruit.getImageId());

        holder.fruitName.setText(fruit.getName());

    }

    @Override

    public int getItemCount() {

        return mFruitList.size();

    }

}

package com.example.recyclerviewtest;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.support.v7.widget.LinearLayoutManager;

import android.support.v7.widget.RecyclerView;

import android.support.v7.widget.StaggeredGridLayoutManager;

import java.util.ArrayList;

import java.util.List;

import java.util.Random;

public class MainActivity extends AppCompatActivity {

    private List<Fruit> fruitList = new ArrayList<Fruit>();

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        initFruits();

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

        StaggeredGridLayoutManager layoutManager = new

                StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);

        recyclerView.setLayoutManager(layoutManager);

        FruitAdapter adapter = new FruitAdapter(fruitList);

        recyclerView.setAdapter(adapter);

    }

    private void initFruits() {

        for (int i = 0; i < 2; i++) {

            Fruit apple = new Fruit(getRandomLengthName("Apple"), R.drawable.apple_pic);

            fruitList.add(apple);

            Fruit banana = new Fruit(getRandomLengthName("Banana"), R.drawable.banana_pic);

            fruitList.add(banana);

            Fruit orange = new Fruit(getRandomLengthName("Orange"), R.drawable.orange_pic);

            fruitList.add(orange);

            Fruit watermelon = new Fruit(getRandomLengthName("Watermelon"), R.drawable.watermelon_pic);

            fruitList.add(watermelon);

            Fruit pear = new Fruit(getRandomLengthName("Pear"), R.drawable.pear_pic);

            fruitList.add(pear);

            Fruit grape = new Fruit(getRandomLengthName("Grape"), R.drawable.grape_pic);

            fruitList.add(grape);

            Fruit pineapple = new Fruit(getRandomLengthName("Pineapple"), R.drawable.pineapple_pic);

            fruitList.add(pineapple);

            Fruit strawberry = new Fruit(getRandomLengthName("Strawberry"), R.drawable.strawberry_pic);

            fruitList.add(strawberry);

            Fruit cherry = new Fruit(getRandomLengthName("Cherry"), R.drawable.cherry_pic);

            fruitList.add(cherry);

            Fruit mango = new Fruit(getRandomLengthName("Mango"), R.drawable.mango_pic);

            fruitList.add(mango);

        }

    }

    private String getRandomLengthName(String name) {

        Random random = new Random();

        int length = random.nextInt(20) + 1;

        StringBuilder builder = new StringBuilder();

        for (int i = 0; i < length; i++) {

            builder.append(name);

        }

        return builder.toString();

    }

}

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"

    android:layout_width="match_parent"

    android:layout_height="wrap_content"

    android:layout_margin="5dp" >

    <ImageView

        android:id="@+id/fruit_image"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_gravity="center_horizontal" />

    <TextView

        android:id="@+id/fruit_name"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_gravity="left"

        android:layout_marginTop="10dp" />

</LinearLayout>

package com.example.recyclerviewtest;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.support.v7.widget.LinearLayoutManager;

import android.support.v7.widget.RecyclerView;

import android.support.v7.widget.StaggeredGridLayoutManager;

import java.util.ArrayList;

import java.util.List;

import java.util.Random;

public class MainActivity extends AppCompatActivity {

    private List<Fruit> fruitList = new ArrayList<Fruit>();

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        initFruits();

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

        StaggeredGridLayoutManager layoutManager = new

                StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);

        recyclerView.setLayoutManager(layoutManager);

        FruitAdapter adapter = new FruitAdapter(fruitList);

        recyclerView.setAdapter(adapter);

    }

    private void initFruits() {

        for (int i = 0; i < 2; i++) {

            Fruit apple = new Fruit(getRandomLengthName("Apple"), R.drawable.apple_pic);

            fruitList.add(apple);

            Fruit banana = new Fruit(getRandomLengthName("Banana"), R.drawable.banana_pic);

            fruitList.add(banana);

            Fruit orange = new Fruit(getRandomLengthName("Orange"), R.drawable.orange_pic);

            fruitList.add(orange);

            Fruit watermelon = new Fruit(getRandomLengthName("Watermelon"), R.drawable.watermelon_pic);

            fruitList.add(watermelon);

            Fruit pear = new Fruit(getRandomLengthName("Pear"), R.drawable.pear_pic);

            fruitList.add(pear);

            Fruit grape = new Fruit(getRandomLengthName("Grape"), R.drawable.grape_pic);

            fruitList.add(grape);

            Fruit pineapple = new Fruit(getRandomLengthName("Pineapple"), R.drawable.pineapple_pic);

            fruitList.add(pineapple);

            Fruit strawberry = new Fruit(getRandomLengthName("Strawberry"), R.drawable.strawberry_pic);

            fruitList.add(strawberry);

            Fruit cherry = new Fruit(getRandomLengthName("Cherry"), R.drawable.cherry_pic);

            fruitList.add(cherry);

            Fruit mango = new Fruit(getRandomLengthName("Mango"), R.drawable.mango_pic);

            fruitList.add(mango);

        }

    }

    private String getRandomLengthName(String name) {

        Random random = new Random();

        int length = random.nextInt(20) + 1;

        StringBuilder builder = new StringBuilder();

        for (int i = 0; i < length; i++) {

            builder.append(name);

        }

        return builder.toString();

    }

}

package com.espressif.activitytest;

/**

 * Created by dongdong on 2018/6/18.

 */

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ImageView;

import android.widget.TextView;

import android.widget.Toast;

import java.util.ArrayList;

import java.util.List;

public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder>{

    private List<Fruit> mFruitList;

    private List<Fruit> fruitList = new ArrayList<Fruit>();

    static class ViewHolder extends RecyclerView.ViewHolder {

        View fruitView;

        ImageView fruitImage;

        TextView fruitName;

        public ViewHolder(View view) {

            super(view);

            fruitView = view;

            fruitImage = (ImageView) view.findViewById(R.id.fruit_image);

            fruitName = (TextView) view.findViewById(R.id.fruit_name);

        }

    }

    public FruitAdapter(List<Fruit> fruitList) {

        mFruitList = fruitList;

    }

    @Override

    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item, parent, false);

        final ViewHolder holder = new ViewHolder(view);

        holder.fruitView.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                int position = holder.getAdapterPosition();

                Fruit fruit = mFruitList.get(position);

                Toast.makeText(v.getContext(), "you clicked view " + fruit.getName(), Toast.LENGTH_SHORT).show();

            }

        });

        holder.fruitImage.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                int position = holder.getAdapterPosition();

                Fruit fruit = mFruitList.get(position);

                Toast.makeText(v.getContext(), "you clicked image " + fruit.getName(), Toast.LENGTH_SHORT).show();
}

        });
        return holder;

    }

    @Override

    public void onBindViewHolder(ViewHolder holder, int position) {

        Fruit fruit = mFruitList.get(position);

        holder.fruitImage.setImageResource(fruit.getImageId());

        holder.fruitName.setText(fruit.getName());

    }

    @Override

    public int getItemCount() {

        return mFruitList.size();

    }

}

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