View binding technique of Android RecyclerView V7 framework
View binding technique of Android RecyclerView V7 framework
RecyclerView is a powerful and flexible list view control that plays an important role in Android development.It provides many functions in the V7 package, including convenient view binding techniques to optimize the display and interaction of the list items.This article will introduce several techniques for viewing view binding using Android Recyclerview V7 frameworks, and provide corresponding Java code examples for each technique.
1. Viewholder mode
The ViewHolder mode is a common technique that optimizes RecyclerView performance.It reduces memory occupation and rendering time by reusing existing views.When using the ViewHolder mode, we need to create a ViewHolder class for cache and management view elements.The following is a simple example, showing how to use the ViewHolder mode in RecyclerView:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private List<String> data;
public MyAdapter(List<String> data) {
this.data = data;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.item_view, parent, false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
String itemData = data.get(position);
holder.bindData(itemData);
}
@Override
public int getItemCount() {
return data.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
private TextView textView;
public MyViewHolder(View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.text_view);
}
public void bindData(String itemData) {
textView.setText(itemData);
}
}
}
In the above example, we created a MyAdapter and passed the data source to it.In OncreateViewHolder, we use the layout file (R.Layout.item_view) to create a view and associate it with ViewHolder.Then, in OnbindViewHolder, we obtain the data of the list item and use the BindData method of ViewHolder to bind it to the view element.
2. Data Binding Library
The data binding library is part of the Android support library, which enables us to directly declare the binding relationship in the layout file without writing a large amount of FindViewByid code.The following is an example code, showing how to use a data binding library in RecyclerView:
First, make sure that the data binding function is enabled in the Build. Gradle file:
groovy
android {
...
dataBinding {
enabled = true
}
}
Then, create a layout file (item_view.xml), and declare the binding relationship in it:
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="itemData"
type="java.lang.String"/>
</data>
<LinearLayout
...
android:orientation="vertical">
<TextView
...
android:text="@{itemData}"/>
</LinearLayout>
</layout>
In the adapter, we only need to use the Bindingutil class of the data binding library to obtain the ItemView binding instance and request the viewing of the view:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private List<String> data;
public MyAdapter(List<String> data) {
this.data = data;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
ItemViewBinding binding = ItemViewBinding.inflate(inflater, parent, false);
return new MyViewHolder(binding);
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
String itemData = data.get(position);
holder.binding.setItemData(itemData);
}
@Override
public int getItemCount() {
return data.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
private ItemViewBinding binding;
public MyViewHolder(ItemViewBinding binding) {
super(binding.getRoot());
this.binding = binding;
}
}
}
In the above example, we created a binding instance (binding) and used the Inflate method to convert the layout file into a binding instance.We then pass the data item to the binding instance and request viewing.
In summary, understanding and mastering the view binding technique of Android Recyclerview V7 framework is very important for the display and interaction of the optimization list view.The code examples above can help you better understand and use these techniques.I hope this article will help you, I wish you success in Android development!
