How to use RecycleView And CardView : Chapter 5

Before starting chapter 5. I hope you have read basic set up  ANDROID FOR BEGINNER CHAPTER 2 : INTRODUCTION OF BASIC UI COMPONENTS . Here we will just focus on basic  about RecycleView and CardView only. 

RecyclerView:-
The RecyclerView widget is a more extended and reusable version of ListView. This widget is very useful to show large data sets that can be scrolled very efficiently by maintaining a limited number of views. Use the RecyclerViewwidget instead of ListView for better perfomance.
CardView also advance FrameLayout  with additional tags like

Layout Manager:-
 RecyclerView provides these built-in layout managers:

• LinearLayoutManager shows items in a vertical or horizontal scrolling list.
• GridLayoutManager shows items in a grid.
• StaggeredGridLayoutManager shows items in a staggered grid.

Examples:-

<!-- A RecyclerView with some commonly used attributes -->

<android.support.v7.widget.RecyclerView

    android:id="@+id/my_recycler_view"

    android:scrollbars="vertical"

    android:layout_width="match_parent"

    android:layout_height="match_parent"/> 

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);

        // use this setting to improve performance if you know that changes
        // in content do not change the layout 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);
    }
    ...
}

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

    // Provide a reference to the views for each data item
    // Complex data items may need more than one view per item, and
    // you provide access to all the views for a data item in a view holder
    public static class ViewHolder extends RecyclerView.ViewHolder {
        // each data item is just a string in this case
        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, parent, false);
        // 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;
    }
}

my_text_view.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    ... >
    <!-- A CardView that contains a TextView -->
    <android.support.v7.widget.CardView
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view"
        android:layout_gravity="center"
        android:layout_width="200dp"
        android:layout_height="200dp"
        card_view:cardCornerRadius="4dp">

        <TextView
            android:id="@+id/info_text"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
    </android.support.v7.widget.CardView>
</LinearLayout>

CardView :-

It is also extended version of FrameLayout with advanced attributes. 

We give elevation , radius and background color

card_view:cardElevation: for creating shadow

• To set the corner radius in your layouts, use the card_view:cardCornerRadius attribute.
• To set the corner radius in your code, use the CardView.setRadius method.
• To set the background color of a card, use the card_view:cardBackgroundColor attribute.

Download Views :-
To use these 2 component  just added following dependency 

dependencies {    ...    compile 'com.android.support:cardview-v7:21.0.+'    compile 'com.android.support:recyclerview-v7:21.0.+'}

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