RecyclerView

RecyclerView是一个更高级柔性版本的Listview，RecyclerView是一个能包含很多视图的容器，它能完美的处理循环和滚动。在item动态变化的Listview使用RecyclerView。

RecyclerView使用很简单，因为它提供了：

1、定位item的布局管理器

2、常见的item操作默认动画

你能够灵活的为RecyclerView自定义布局管理器和动画。

使用RecyclerView，必须使用指定一个adapter、定义一个布局管理器。创建adapter必须继承自RecyclerView.Adapter。实施的细节需要看数据类型和需要的视图。

RecyclerView widget

RecyclerView 提供了 LayoutManager，RecylerView 不负责子 View 的布局，我们可以自定义 LayoutManager 来实现不同的布局效果，目前只提供了LinearLayoutManager。 LinearLayoutManager 可以指定方向，默认是垂直， 可以指定水平， 这样就轻松实现了水平的 ListView。

RecyclerView Demo：

1、布局文件

android:id="@+id/my_recycler_view"
android:scrollbars="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"/>

2、Activity文件

public class MyActivity extends Activity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_activity);
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

// improve performance if you know that changes in content
// do not change the size of the RecyclerView
mRecyclerView.setHasFixedSize(true);

// use a linear layout manager
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);

// specify an adapter (see also next example)
mAdapter = new MyAdapter(myDataset);
mRecyclerView.setAdapter(mAdapter);
}
...
}
To create a simple adapter:

public class MyAdapter extends RecyclerView.Adapter {
private String[] mDataset;

// Provide a reference to the type of views that you are using
// (custom viewholder)
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView mTextView;
public ViewHolder(TextView v) {
super(v);
mTextView = v;
}
}

// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(String[] myDataset) {
mDataset = myDataset;
}

// Create new views (invoked by the layout manager)
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.my_text_view, null);
// set the view's size, margins, paddings and layout parameters
...
ViewHolder vh = new ViewHolder(v);
return vh;
}

// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
holder.mTextView.setText(mDataset[position]);

}

// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
return mDataset.length;
}
}

3、Recycler adapter

public class MyAdapter extends RecyclerView.Adapter {
private String[] mDataset;

// Provide a reference to the type of views that you are using
// (custom viewholder)
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView mTextView;
public ViewHolder(TextView v) {
super(v);
mTextView = v;
}
}