Android RecyclerView初探

原文:https://github.com/dyguests/RecyclerViewDemo

RecyclerView是用于替换ListView的解决方案，将视图控制和数据绑定做了分离，提供了强大的样式定制能力

使用教程

1.准备工作

在 module 的 build.gradle 中 加入

compile 'com.android.support:recyclerview-v7:23.3.0'

代码:

dependencies {
...
compile 'com.android.support:recyclerview-v7:23.3.0'//1.1
...
}

2.使用RecyclerView

2.1.在xml中添加RecyclerView

activity_linear_layout_manager.xml

<RelativeLayout
...>
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:listitem="@layout/item_linear"/>
</RelativeLayout>

注:

tools:listitem="@layout/item_linear"

是用于在Android Studio的Preview中查看效果用的

2.2.在java中添加RecyclerView

LinearLayoutManagerActivity.java

2.2.1.绑定

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

2.2.2.添加

LayoutManager

(布局方式)

mRecyclerView.setLayoutManager(new LinearLayoutManager(this,
LinearLayoutManager.VERTICAL/*方向*/,
false/*是否反向*/
));

注:这里用

LinearLayoutManager

表示这是使用线性布局,也可以使用

GridLayoutManager

等.

2.2.3.绑定Adapter(参考 2.3.创建Adapter)

mAdapter = new LinearLayoutManagerAdapter(this);
mRecyclerView.setAdapter(mAdapter);

2.2.4.添加数据

...
mAdapter.addItem(user);
...

也可以使用

...
mAdapter.addItems(users);
...

注:

addItem()

,

addItems()

方法是自定义的,主要是为了把数据添加操作和动画放在一起.

2.3.创建Adapter

2.3.1.创建

LinearLayoutManagerAdapter

类

public class LinearLayoutManagerAdapter{

}

2.3.2.让类继承

RecyclerView.Adapter

public class LinearLayoutManagerAdapter extends RecyclerView.Adapter{

}

2.3.3.注意,

RecyclerView.Adapter

是泛型类,需要一个继承至

RecyclerView.ViewHolder

的泛型参数(?),这里我们创建一个

ViewHolder

的内部类:

public class LinearLayoutManagerAdapter extends RecyclerView.Adapter{

public class ViewHolder extends RecyclerView.ViewHolder{

}
}

2.3.4.添加泛型声明

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

public class ViewHolder extends RecyclerView.ViewHolder{

}
}

2.3.5.实现方法

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

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return null;
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {

}

@Override
public int getItemCount() {
return 0;
}

public class ViewHolder extends RecyclerView.ViewHolder{

public ViewHolder(View itemView) {
super(itemView);
}
}
}

2.3.6.添加构造器

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

private final Context context;

public LinearLayoutManagerAdapter(Context context) {
this.context = context;
}

...
}

2.3.7.指定

item_view

,注意这里与ListView不同,这里不返回View,而是返回ViewHolder(自已定义的).

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.item_linear, parent, false);
return new ViewHolder(view);
}

2.3.8.添加数据源

public class LinearLayoutManagerAdapter extends RecyclerView.Adapter<LinearLayoutManagerAdapter.ViewHolder>{
...
private final ArrayList<User> list;

public LinearLayoutManagerAdapter(Context context) {
this.context = context;
list = new ArrayList<>();
}
...
@Override
public int getItemCount() {
return list.size();
}
...
}

2.3.9.实现

list_item

与数据的绑定

public class LinearLayoutManagerAdapter extends RecyclerView.Adapter<LinearLayoutManagerAdapter.ViewHolder>{
...
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.bind(list.get(position));
}
...
public class ViewHolder extends RecyclerView.ViewHolder{
...
public void bind(User data) {
}
}
}

2.3.10.在

ViewHolder

中实现布局元素的绑定与数据的绑定

public class ViewHolder extends RecyclerView.ViewHolder {
private final TextView mTextView;
private       User     data;

public ViewHolder(View itemView) {
super(itemView);
mTextView = ((TextView) itemView.findViewById(R.id.text_view));
}

public void bind(User data) {
mTextView.setText(data.getName());

this.data = data;
}
}

这里注意一下,请尽量把

ViewHolder

相关的布局元素绑定,数据绑定放到

ViewHolder

中来实现,而不要放到

onCreateViewHolder()

,

onBindViewHolder()

中去实现.

2.3.11.其它相关代码

//-----------------------数据增删相关-------------------------------

public void addItem(User item) {
int positionStart = list.size();
list.add(item);
notifyItemInserted(positionStart);
}

public void addItems(List<User> items) {
int positionStart = list.size();
list.addAll(items);
notifyItemRangeInserted(positionStart, items.size());
}

public void clear() {
int itemCount = list.size();
list.clear();
notifyItemRangeRemoved(0, itemCount);
}

注:这段代码是为了方便把数据增删和动画效果绑定要一起

3.其它几种例子

LinearLayoutManagerActivity

GridLayoutManagerActivity

InContainerActivity