ButterKnife Simple

Step - 1 : Add this library to gradle

compile 'com.jakewharton:butterknife:6.1.0'

Step - 2 : activity_main.xml

<?xml version="1.0" encoding="utf-8"?><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:orientation="vertical"    android:background="#ffffff"    tools:context="cmsecomm.ecommerce.app.com.butterknife.MainActivity">
    <TextView        android:id="@+id/tv1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="Hello World!"        android:textColor="#000000"        />    <Button        android:id="@+id/btn1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Button1"        />    <Button        android:id="@+id/btn2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Button2"        />    <Button        android:id="@+id/btn3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Button3"        />
</LinearLayout>

Step - 3 : MainActivity.java

import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.widget.Button;import android.widget.TextView;
import butterknife.ButterKnife;import butterknife.InjectView;import butterknife.OnClick;
public class MainActivity extends AppCompatActivity {

    @InjectView(R.id.tv1)
    TextView tv1;    @InjectView(R.id.btn1)
    Button b1;    @InjectView(R.id.btn2)
    Button b2;    @InjectView(R.id.btn3)
    Button b3;

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.inject(this);
        tv1.setText("New Auto Text");    }
    @OnClick(R.id.btn1)
    void buttonClick()
    {
        tv1.setText("Button1");    }

    @OnClick({R.id.btn2, R.id.btn3})
    void performClick()
    {
        tv1.setText("Button 2 & 3 mixed click");    }
}