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RecyclerView纵向和横向滚动 RecyclerView实现纵向和横向滚动

Imfondof 人气:3

为方便自己以后学习,自己记录学习,大家也可以参考,有什么问题一起探讨。

今天学习RecyclerView,下边来说一下实现数据垂直滚动和数据横向滚动。先上图为敬:

所用工具:Android Studio

纵向滚动

1、添加依赖库:

打开app/build.gradle文件,在dependencies闭包中添加如下内容(compile 'com.android.support:recyclerview-v7:24.2.1'为添加的内容)

dependencies {
 compile fileTree(dir: 'libs', include: ['*.jar'])
 androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
 exclude group: 'com.android.support', module: 'support-annotations'
 })
 compile 'com.android.support:appcompat-v7:26.0.0-alpha1'
 compile 'com.android.support:recyclerview-v7:24.2.1'
 testCompile 'junit:junit:4.12'
}

添加完之后点击一下Sync Now来进行同步;

2、修改activity_main.xml中的代码:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:id="@+id/activity_main"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context="com.example.dell.practice_recyclerview.MainActivity">
<android.support.v7.widget.RecyclerView
 android:id="@+id/id_recycler_view"
 android:layout_width="match_parent"
 android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
 
</LinearLayout>

因为RecyclerView不是内置在系统SDK中的,所以需要把完整的包路径写出来。

3、新建实体类,这里以Book类作为演示:

package com.example.dell.practice_recyclerview;
 
/**
 * Created by dell on 2018/6/3.
 * Created by qiyueqing on 2018/6/3.
 */
 
public class Book {
 private String name;
 private int imageId;
 
 public Book(String name, int imageId) {
 this.name = name;
 this.imageId = imageId;
 }
 
 public String getName() {
 return name;
 }
 
 public int getImageId() {
 return imageId;
 }
}

4、为ListView的子项制定一个我们自定义的布局:

在layout目录下新建book_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="wrap_content">
 
 <ImageView
 android:id="@+id/id_book_image"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"/>
 <TextView
 android:id="@+id/id_book_name"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_vertical"
 android:layout_marginLeft="10dp"/>
</LinearLayout>

5、为RecyclerView准备一个适配器:

新建BookAdapter类,让这个类继承RecyclerView.Adapter,并将泛型指定为BookAdapter.ViewHolder;

里边自定义一个内部类ViewHolder,里边的构造参数传入view参数,这个参数就是RecyclerView的最外层布局,这样就可以通过findViewById()来货渠道布局中的ImageView和TextView的实例了;

BookAdapter中的构造函数,这个方法吧要展示的数据源传进来,并赋值给一个全局变量mBookAdapter,我们后继的所有操作都将在这个数据源的基础上进行;重写三个方法;

package com.example.dell.practice_recyclerview;
 
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 java.util.List;
 
/**
 * Created by dell on 2018/6/3.
 * Created by qiyueqing on 2018/6/3.
 */
 
public class BookAdapter extends RecyclerView.Adapter<BookAdapter.ViewHolder>{
 
 private List<Book> mBookList;
 static class ViewHolder extends RecyclerView.ViewHolder{
 ImageView bookImage;
 TextView bookName;
 public ViewHolder(View view){
  super(view);
  bookImage=view.findViewById(R.id.id_book_image);
  bookName=view.findViewById(R.id.id_book_name);
 }
 }
 
 public BookAdapter(List<Book> bookList){
 mBookList=bookList;
 }
 @Override
 public BookAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
 View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.book_item,parent,false);
 RecyclerView.ViewHolder holder=new ViewHolder(view);
 return (ViewHolder) holder;
 }
 
 @Override
 public void onBindViewHolder(BookAdapter.ViewHolder holder, int position) {
 Book book=mBookList.get(position);
 holder.bookImage.setImageResource(book.getImageId());
 holder.bookName.setText(book.getName());
 }
 
 @Override
 public int getItemCount() {
 return mBookList.size();
 }
}

6、修改MainActivity中的代码:

package com.example.dell.practice_recyclerview;
 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
 
import java.util.ArrayList;
import java.util.List;
 
public class MainActivity extends AppCompatActivity {
 
 private List<Book> bookList=new ArrayList<>();
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 initBooks();
 RecyclerView recyclerView= (RecyclerView) findViewById(R.id.id_recycler_view);
 LinearLayoutManager layoutManager=new LinearLayoutManager(this); //LinearLayoutManager中定制了可扩展的布局排列接口,子类按照接口中的规范来实现就可以定制出不同排雷方式的布局了
 
 //配置布局,默认为vertical(垂直布局),下边这句将布局改为水平布局
 //layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
 recyclerView.setLayoutManager(layoutManager);
 BookAdapter adapter=new BookAdapter(bookList);
 recyclerView.setAdapter(adapter);
 }
 
 private void initBooks(){
 for (int i=1;i<11;i++){
  Book book=new Book("春起之苗"+i,R.drawable.icon_book);
  bookList.add(book);
 }
 }
}

此时运行即可看到纵向的展示样例了。

实现横向滚动:

修改book_item中的代码:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="100dp"
 android:layout_height="wrap_content">
 
 <ImageView
 android:id="@+id/id_book_image"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"/>
 <TextView
 android:id="@+id/id_book_name"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:layout_marginLeft="10dp"/>
</LinearLayout>

2、修改MainActivity中的代码

package com.example.dell.practice_recyclerview;
 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
 
import java.util.ArrayList;
import java.util.List;
 
public class MainActivity extends AppCompatActivity {
 
 private List<Book> bookList=new ArrayList<>();
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 initBooks();
 RecyclerView recyclerView= (RecyclerView) findViewById(R.id.id_recycler_view);
 LinearLayoutManager layoutManager=new LinearLayoutManager(this); //LinearLayoutManager中定制了可扩展的布局排列接口,子类按照接口中的规范来实现就可以定制出不同排雷方式的布局了
 
 //配置布局,默认为vertical(垂直布局),下边这句将布局改为水平布局
 layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
 recyclerView.setLayoutManager(layoutManager);
 BookAdapter adapter=new BookAdapter(bookList);
 recyclerView.setAdapter(adapter);
 }
 
 private void initBooks(){
 for (int i=1;i<11;i++){
  Book book=new Book("春起之苗"+i,R.drawable.icon_book);
  bookList.add(book);
 }
 }
}

例子下载地址:RecyclerView实现纵向和横向滚动

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