ListView实现单选功能

1–控件要实现单选，首先要让控件实现Checkable接口，并继承某一个Layout。
控件的原始代码：

package com.example.chencklist;

import android.content.Context;
import android.view.View;
import android.widget.Checkable;
import android.widget.FrameLayout;
import android.widget.RadioButton;
import android.widget.TextView;

public class SingleView extends FrameLayout implements Checkable{

    TextView tv_item;
    RadioButton rb_item;

    public SingleView(Context context) {
        super(context);
        View.inflate(context, R.layout.item_check_view, this);
        tv_item = (TextView) findViewById(R.id.tv_item);
        rb_item = (RadioButton) findViewById(R.id.rb_item);
    }

    public void setText(String str) {
        tv_item.setText(str);
    }

    @Override
    public void setChecked(boolean checked) {
        rb_item.setChecked(checked);

    }

    @Override
    public boolean isChecked() {
        return rb_item.isChecked();
    }

    @Override
    public void toggle() {
        rb_item.toggle();

    }

}

2–R.layout.item_check_view的xml布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <RadioButton
        android:id="@+id/rb_item"
        android:layout_width="wrap_content"
        android:layout_height="48dp"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:clickable="false"
        android:focusable="false"
        android:focusableInTouchMode="false" />

    <TextView
        android:id="@+id/tv_item"
        android:layout_width="wrap_content"
        android:layout_height="48dp"
        android:layout_alignParentRight="true"
        android:gravity="center_vertical"
        android:text="name" />

RelativeLayout>

注意，以上的这三个属性必须为false：
android:clickable=”false”
android:focusable=”false”
android:focusableInTouchMode=”false”
否则，布局中的radiobutton可以被点击，并且获得焦点；当点击item的其他地方是正常的，但是若点击item中的radiobutton时，则会和item的点击事件发生冲突，使得item点击事件失效，视觉上会造成多个radiobutton被选中的状态。

3–自定义的adapter，继承自ArrayAdapter。
因为源生代码中，ListView的ListView.CHOICE_MODE_SINGLE属性（单选模式）是结合ArrayAdapter使用的。

package com.example.chencklist;

import java.util.List;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;

public class MyArrayAdapter extends ArrayAdapter<Bean>{

    private Context context;

    public MyArrayAdapter(Context context, int resource, List objects) {
        super(context, resource, objects);
        this.context = context;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        SingleView view = null;
        if (convertView == null) {
            view = new SingleView(context);
        }else {
            view = (SingleView) convertView;
        }
        view.setText(getItem(position).getName());
        return view;
    }

}

4–自定义的测试实体类Bean

package com.example.chencklist;

import java.io.Serializable;

public class Bean implements Serializable{

    private static final long serialVersionUID = -4788371797955109344L;

    String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }


}

5–MainActivity中的代码：

package com.example.chencklist;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {

    Button btn;
    ListView lv;
    List beans = new ArrayList();
    Bean checkedBean = new Bean();//被选中的Bean

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn = (Button) findViewById(R.id.btn_main);
        lv = (ListView) findViewById(R.id.lv_main);
        lv.setChoiceMode(ListView.CHOICE_MODE_SINGLE);//设置单选模式，也可以在xml中直接设置
    }

    @Override
    protected void onResume() {
        setBeans();

        ListAdapter adapter = new MyArrayAdapter(MainActivity.this, R.layout.item_check_view, beans);
        lv.setAdapter(adapter);
        lv.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView parent, View view,
                    int position, long id) {
                    //注意要对被选择的Bean做非空判断
                checkedBean = beans.get(position);//获取到被选择的Bean

            }
        });
        btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                //拿到被选择的Bean
                Toast.makeText(MainActivity.this, checkedBean.getName(), Toast.LENGTH_SHORT).show();
            }
        });

        super.onResume();
    }

    //数据添加
    private void setBeans() {
        Bean bean1 = new Bean();
        bean1.setName("name1");
        Bean bean2 = new Bean();
        bean2.setName("name2");
        Bean bean3 = new Bean();
        bean3.setName("name3");
        Bean bean4 = new Bean();
        bean4.setName("name4");
        beans.add(bean1);
        beans.add(bean2);
        beans.add(bean3);
        beans.add(bean4);
    }



}

6–MainActivity的xml布局

<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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.chencklist.MainActivity" >

    <Button
        android:id="@+id/btn_main"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:text="button" />

    <ListView
        android:id="@+id/lv_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
    ListView>

LinearLayout>

以上，实现ListView的单选功能。