Android - check box CheckBox

1. Realize the effect

 

2. Layout xml file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <CheckBox
        android:id="@+id/like_shuttlecock"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="羽毛球"
        android:textSize="18sp"
        />
    <CheckBox
        android:id="@+id/like_basketball"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="篮球"
        android:textSize="18sp"
        />
    <CheckBox
        android:id="@+id/like_pingpong"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="乒乓球"
        android:textSize="18sp"
        />
    <TextView
        android:id="@+id/hobby"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        />

</LinearLayout>

 3. MainActivity.java file

Implement the setOnCheckedChangeListener interface, and set the listening events of the three checkbox controls. And rewrite the onCheckedChanged() method of the interface, and implement the click event in this method.

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener {
   private TextView hobby;
   private String hobbys;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        CheckBox shuttlecock=(CheckBox) findViewById(R.id.like_shuttlecock);
        CheckBox basketball=(CheckBox)findViewById(R.id.like_basketball);
        CheckBox pingpong=(CheckBox)findViewById(R.id.like_pingpong);
        shuttlecock.setOnCheckedChangeListener(this);//在此处按住Alt+enter，选择Make 'MainActivity'会自动出现27行
        basketball.setOnCheckedChangeListener(this);//设置三个接口，下面再定义方法
        pingpong.setOnCheckedChangeListener(this);
        hobby=(TextView) findViewById(R.id.hobby);
        hobbys= new String();
    }

    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        String motion=buttonView.getText().toString();
        if (isChecked){
            if (!hobbys.contains(motion)) {
                hobbys = hobbys + motion;
                hobby.setText(hobbys);
            }
            }else{
                if (hobbys.contains(motion)){//如果没被选中
                    hobbys=hobbys.replace(motion,"");//使用空字符串替换
                    hobby.setText(hobbys);
                }
            }

    }
}