Monday, 27 July 2015

HB Blog 85: Creating Material Design Listing Using RecyclerView And CardView.

In this post, I will show how to use card view and recyclerview for listing data items. To create complex lists and cards with material design styles in your apps, you can use the RecyclerView and CardView widgets.

RecyclerView:- A flexible view for providing a limited window into a large data set. 
The RecyclerView widget is a more advanced and flexible version of ListView. This widget is a container for displaying large data sets that can be scrolled very efficiently by maintaining a limited number of views. To use the RecyclerView widget, you have to specify an adapter and a layout manager. To create an adapter, extend the RecyclerView.Adapter class. The details of the implementation depend on the specifics of your dataset and the type of views. A layout manager positions item views inside a RecyclerView and determines when to reuse item views that are no longer visible to the user. To reuse (or recycle) a view, a layout manager may ask the adapter to replace the contents of the view with a different element from the dataset.
CardView:- A FrameLayout with a rounded corner background and shadow. 
The CardView uses elevation property in lollipop version for shadows and falls back to a custom shadow implementation on older platforms. To create a card with a shadow, use the card_view:cardElevation attribute. CardView uses real elevation and dynamic shadows on Android 5.0 (API level 21) and above and falls back to a programmatic shadow implementation on earlier versions.

The RecyclerView and CardView widgets are part of the v7 Support Libraries. To use these widgets in your project, add these Gradle dependencies to your app's module:
dependencies {
    compile 'com.android.support:cardview-v7:21.0.+'
    compile 'com.android.support:recyclerview-v7:21.0.+'
}

Refer the below link for complete sample code:-
Download Sample Code
Download Apk File
Have a look on few code snippets,

RecycleViewActivity.java 
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import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;


/**
 * Created by harshalbenake on 02/06/15.
 */
public class RecycleViewActivity extends Activity {
     RecyclerView mRecyclerView;
     RecyclerView.Adapter mAdapter;
     RecyclerView.LayoutManager mLayoutManager;
     String[] myDataset;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_recycle_view);

        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(RecycleViewActivity.this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        myDataset = new String[101];
        for (int i = 0; i < 101; i++)
        {
            myDataset[i] = String.format("Harshal Benake: "+i, i);
        }

        // specify an adapter
        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 class ViewHolder extends RecyclerView.ViewHolder {
            // each data item is just a string in this case
            public TextView mTextView;
            public ViewHolder(View v) {
                super(v);
                mTextView=(TextView)v.findViewById(R.id.row_textView);
            }
        }

        // 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 view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_item, parent, false);

            // set the view's size, margins, paddings and layout parameters
            ViewHolder viewHolder = new ViewHolder(view);
            return viewHolder;
        }

        // 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;
        }
    }
}

main_recycle_view.xml 
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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <!-- A RecyclerView with some commonly used attributes -->
    <android.support.v7.widget.RecyclerView
        android:id="@+id/my_recycler_view"
        android:scrollbars="none"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</LinearLayout>

row_item.xml 
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<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:id="@+id/card_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="10dp"
    card_view:cardCornerRadius="4dp">

    <TextView
        android:id="@+id/row_textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:elevation="2dp"
        android:text="New Text" />
</android.support.v7.widget.CardView>

build.gradle 
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apply plugin: 'com.android.application'

android {
    compileSdkVersion 21
    buildToolsVersion "22.0.1"

    defaultConfig {
        applicationId "com.lollipopsupport_as"
        minSdkVersion 15
        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.+'
    compile 'com.android.support:cardview-v7:21.0.+'
    compile 'com.android.support:recyclerview-v7:21.0.+'

}
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1 comment:

  1. Anonymous2 March 2016 at 10:24

    if i want to add a click function. i should add in the where ??

    ReplyDelete

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