AS：checkbox复选框的两种实现

1） 主动报告（监听按钮变化）
效果图：
代码：
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:id="@+id/layout" tools:context=".MainActivity" >
    <CheckBox android:id="@+id/checkbox1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="游泳" android:textSize="30dp"/>
    <CheckBox android:id="@+id/checkbox2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="跑步" android:textSize="30dp"/>
    <CheckBox android:id="@+id/checkbox3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="篮球" android:textSize="30dp" />
    <Button android:id="@+id/ok_bt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="OK"/>

   <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="0项选择" android:textSize="30dp"/>
</LinearLayout>

Main

public class MainActivity extends AppCompatActivity {
   
    Button myBtn1;
    private CheckBox CheckBox1;
    private CheckBox CheckBox2;
    private CheckBox CheckBox3;

    private boolean[] checkedArray = new boolean[] {
   false, false, false};

    private TextView textView;
    private LinearLayout mLayout;

    public MainActivity() {
   
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.checkbox); 
        //通过id找到按钮
        CheckBox1 = (CheckBox) findViewById(R.id.checkbox1);
        CheckBox2 = (CheckBox) findViewById(R.id.checkbox2);
        CheckBox3 = (CheckBox) findViewById(R.id.checkbox3);
        textView = (TextView) findViewById(R.id.textView1);
        //为按钮1添加一个监听事件，如果被选中，就把结果赋给数组
        CheckBox1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
   
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
   
                checkedArray[0] = isChecked;
                textViewResetValue();
            }
        });
        CheckBox2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
   
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
   
                checkedArray[1] = isChecked;
                textViewResetValue();
            }
        });
        CheckBox3.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
   
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
   
                checkedArray[2] = isChecked;
                textViewResetValue();
            }
        });

        setContentView(R.layout.layoutdemo);
        TextView textview = findViewById(R.id.tv4);
        textview.setMovementMethod(LinkMovementMethod.getInstance());
}
    //这个方法的作用就是时事显示
    private void textViewResetValue() {
   
        String values = "";
        int sumChecked = 0;
        for (boolean val : checkedArray)
            if (val == true)
                sumChecked += 1;
        if (sumChecked == 0)
            textView.setText("0 项选择");
        else {
   
            if (checkedArray[0] == true) values += ",篮球";
            if (checkedArray[1] == true) values += ",足球";
            if (checkedArray[2] == true) values += ",乒乓球";
            values = sumChecked + "项选择：" + values.substring(1);
            textView.setText(values);
        }
    }
}

2）被动获知（通过提交按钮提交选择）
效果图：

代码：

<?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:id="@+id/layout" tools:context=".MainActivity" >
    <CheckBox android:id="@+id/checkbox1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="游泳" android:textSize="30dp"/>
    <CheckBox android:id="@+id/checkbox2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="跑步" android:textSize="30dp"/>
    <CheckBox android:id="@+id/checkbox3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="篮球" android:textSize="30dp" />
    <Button android:id="@+id/ok_bt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="OK"/>
</LinearLayout>

main

    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.checkbox);
        initViews();
    }

 private  void initViews(){
   
        myBtn1=(Button) findViewById(R.id.ok_bt);
        CheckBox1=(CheckBox)findViewById(R.id.checkbox1);
        CheckBox2=(CheckBox)findViewById(R.id.checkbox2);
        CheckBox3=(CheckBox)findViewById(R.id.checkbox3);
        //textView=(TextView)findViewById(R.id.textView1);
        mLayout = (LinearLayout)findViewById(R.id.layout);
        myBtn1.setOnClickListener(new View.OnClickListener() {
   
            @Override
            public void onClick(View v) {
   
                StringBuilder hobby = new StringBuilder();
                //获得子控件的数量
                int count=mLayout.getChildCount();
                for(int i=0;i<count;i++){
   
                    //获得子控件的对象
                    View chlid=mLayout.getChildAt(i);
                    if(chlid instanceof CheckBox){
   
                        CheckBox cb=(CheckBox)chlid;
                        if(cb.isChecked()){
   
                            hobby.append(cb.getText()+"");
                        }
                    }

                }
                if(hobby.length()==0){
   
                    Toast.makeText(MainActivity.this,"没有爱好", Toast.LENGTH_SHORT).show();
                }
                else{
   
                    Toast.makeText(MainActivity.this,"爱好有："+hobby.toString(), Toast.LENGTH_SHORT).show();
                }
            }
        });
    }