RecyclerView Tutorial

Using RecyclerView, we have to be mind about two important aspects i.e
   
    1. RecyclerView.ViewHolder
    2. RecyclerView.Adapter
 

  My DemoApp Structure goes like this :

We will be using android Studio here.

    And Few properties of RecyclerView which i will discuss after code.
 
    So you might have to write something like this to run RecyclerView.

1. RecyclerViewActivity.java

public class RecyclerViewActivity extends Activity {



    ArrayList<String>mListitems;

    RecyclerView mRecyclerView;



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        initiView();

    }



    private void initiView(){

        mListitems=new ArrayList<String>();

        for(int i=0;i<125;i++){

            mListitems.add("List Item "+ i);

        }

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



        // 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);



       //The LinearLayoutManager is currently the only default implementation of LayoutManager. You can use this class to create either vertical or horizontal lists.



        LinearLayoutManager layoutManager = new LinearLayoutManager(RecyclerViewActivity.this);

        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);

        mRecyclerView.setLayoutManager(layoutManager);

  

       //Setting up ItemAnimator here

       mRecyclerView.setItemAnimator(new DefaultItemAnimator());



        //setting up the adapter

        RecyclerViewAdapter mAdapter=new RecyclerViewAdapter(RecyclerViewActivity.this,mListitems);

        mRecyclerView.setAdapter(mAdapter);

    }



}

2. RecyclerViewAdapter.java

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewViewHolder> {



      Context mContext;

      ArrayList<String>mListItems;

        public  RecyclerViewAdapter(Context mContext,ArrayList<String>mListItems){

            this.mContext=mContext;

            this.mListItems=mListItems;

        }





    @Override

    public RecyclerViewViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {

        View itemView = LayoutInflater

                .from(viewGroup.getContext())

                .inflate(R.layout.row_recyclerview, viewGroup, false);

        return new RecyclerViewViewHolder(itemView);

    }



    @Override

    public void onBindViewHolder(RecyclerViewViewHolder recyclerViewViewHolder, int i) {



        recyclerViewViewHolder.txtView.setText(mListItems.get(i));

    }



    @Override

    public int getItemCount() {

        return mListItems.size();

    }

}

3. RecyclerViewViewHolder.java

public class RecyclerViewViewHolder extends RecyclerView.ViewHolder {



public TextView txtView;



    public RecyclerViewViewHolder(View itemView) {

        super(itemView);

        txtView = (TextView) itemView.findViewById(R.id.title);

    }

}

XML files now : 
1. activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">


    <android.support.v7.widget.RecyclerView
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/recyclervew"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
       />
</LinearLayout>

2. row_recyclerview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/txtview"
        android:text="Demo recyclerView"
        android:padding="10dp"
        android:textColor="@android:color/holo_red_dark"
        />
</LinearLayout>

Most important file now 
In App folder : build.gradle
Starts from here :>>>>

apply plugin: 'com.android.application'




android {
    compileSdkVersion 22
    buildToolsVersion "21.1.2"


    defaultConfig {
        applicationId "com.example.kamalvaid.recyclerview"
        minSdkVersion 14
        targetSdkVersion 21
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}


dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:21.0.0'
    compile 'com.android.support:recyclerview-v7:21.0.0'

}

    Now there are using few properties listed below those purpose should be clear

    1. mRecyclerView.setHasFixedSize(true); => use this setting to improve performance if you know that changes in content do not change the layout size of the RecyclerView

    2. LinearlayoutManager => The LinearLayoutManager is currently the only default implementation of LayoutManager. You can use this class to create either vertical or horizontal lists.

    

       And we are using like this

    LinearLayoutManager layoutManager = new LinearLayoutManager(RecyclerViewActivity.this);

    layoutManager.setOrientation(LinearLayoutManager.VERTICAL);            

    layoutManager.setOrientation(LinearLayoutManager.Horizontal);


Also RecyclerView doesn't include Divider property by default, So we have to customize it .

Output : 

      




Happy Coding!!!
Cheers