RecyclerView纵向和横向滚动

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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:

RecyclerView实现纵向和横向滚动-码农教程

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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以上是 RecyclerView纵向和横向滚动 的全部内容, 来源链接: utcz.com/a/117913.html

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