Android support library document file framework: overview and use
The Android support library is a set of libraries for extending the function of Android framework, which aims to provide backward compatibility and better user experience.These libraries provide a series of functions that can help developers build consistent and stable applications on different versions of Android devices.
Overview:
The Android support library is provided by Google and can be downloaded and imported from Android SDK Manager to the Android project.These libraries can be used together with the latest Android platform version, or it can be compatible with the old version.They provide additional APIs and tools for simplifying the development and testing of applications, and provide a better user experience.
use:
1. Provide forward compatibility: Use the support library to ensure that your application maintains consistent behavior and functions on different versions of Android devices.This means that you can use the latest Android function and can still run your application on the old version.
2. Provide additional functions: The support library provides developers with some additional functions and APIs to simplify common development tasks.For example, the RecyclerView support library provides a flexible list display control that can replace the traditional ListView and gridView.Another example is Fragments in the library, which provides a convenient way to manage the UI component of the application.
3. Provide a better user experience: The support library also includes some tools and resources for improving user experience.For example, the AppCompat library allows your application to have the same appearance and behavior consistent with the latest Material Design style.Other libraries also provide animations, transition effects and custom controls that can be used to enhance the application UI.
Java code example:
Below is a simple example of using the RecyclerView support library to show how to display a list in the application:
1. Add the RecyclerView support library to the BUILD.GRADLE file:
dependencies {
implementation 'com.android.support:recyclerview-v7:28.0.0'
}
2. Define RecyclerView in the layout file:
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
3. Initize RecyclerView in Activity or Fragment, and set the layout manager and adapter:
RecyclerView recyclerView = findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(new MyAdapter(data));
4. Create an adapter class and bind data:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private List<String> data;
public MyAdapter(List<String> data) {
this.data = data;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
holder.textView.setText(data.get(position));
}
@Override
public int getItemCount() {
return data.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public TextView textView;
public ViewHolder(View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.textView);
}
}
}
This is just a simple example of using the RecyclerView in the support library. In fact, you can use other support libraries to achieve more complex functions and effects.By using the Android support library, you can easily build a strong, backward, and good user experience Android application.
