引言

??很多時候我們都會在各種app上看到地區(qū)選擇的功能，今天就來使用PickerView來實現(xiàn)地區(qū)三級聯(lián)動的選擇器功能。
??本篇與通過接口解析地區(qū)數(shù)據(jù)的方式不同，而是采用解析本地地區(qū)json文件的方式來解析數(shù)據(jù)。也就是說，無需網(wǎng)絡(luò)連接解析接口，而是直接通過本地工具類解析json文件。話不多說，快來看看怎么實現(xiàn)吧！

效果預(yù)覽

用法

步驟一、引入第三方依賴庫

在app下build.gradle中添加如下依賴：

//PickerView庫
implementation 'com.contrarywind:Android-PickerView:4.1.9'

步驟二、布局文件

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
        tools:context=".blog.Case46"
        tools:ignore="MissingConstraints">
       
    <Button
        android:id="@+id/btnAreaPicker"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:background="@color/green"
        android:text="地區(qū)三級聯(lián)動"
        android:textColor="@color/white"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

步驟三、添加地區(qū)json文件

請移步github中下載該文件
傳送門：地區(qū)（省-市-區(qū)）json文件
添加到AndroidStudio中：app——main——src——assets文件夾中

步驟四、創(chuàng)建DataBean類

/**
 * @data on 2020/11/2 3:30 PM
 * @auther armStrong
 * @describe 地區(qū)json解析類
 */
public class ProviceBean {

    /**
     * name : 北京市
     * city : [{"name":"北京市","area":["東城區(qū)","西城區(qū)","崇文區(qū)","宣武區(qū)","朝陽區(qū)","豐臺區(qū)","石景山區(qū)","海淀區(qū)","門頭溝區(qū)","房山區(qū)","通州區(qū)","順義區(qū)","昌平區(qū)","大興區(qū)","平谷區(qū)","懷柔區(qū)","密云縣","延慶縣"]}]
     */

    private String name;
    private List<CityBean> city;

    public String getName() {
        return name;
    }

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

    public List<CityBean> getCity() {
        return city;
    }

    public void setCity(List<CityBean> city) {
        this.city = city;
    }

    public static class CityBean {
        /**
         * name : 北京市
         * area : ["東城區(qū)","西城區(qū)","崇文區(qū)","宣武區(qū)","朝陽區(qū)","豐臺區(qū)","石景山區(qū)","海淀區(qū)","門頭溝區(qū)","房山區(qū)","通州區(qū)","順義區(qū)","昌平區(qū)","大興區(qū)","平谷區(qū)","懷柔區(qū)","密云縣","延慶縣"]
         */

        private String name;
        private List<String> area;

        public String getName() {
            return name;
        }

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

        public List<String> getArea() {
            return area;
        }

        public void setArea(List<String> area) {
            this.area = area;
        }
    }
}

步驟五、解析數(shù)據(jù)工具類

/**
 * @data on 2020/11/2 3:32 PM
 * @auther armStrong
 * @describe 讀取Assent資源文件中的并將.json文件轉(zhuǎn)換成String類型
 */
public class GetJsonDataUtil {
    public String getJson(Context context, String fileName) {

        StringBuilder stringBuilder = new StringBuilder();
        try {
            AssetManager assetManager = context.getAssets();
            BufferedReader bf = new BufferedReader(new InputStreamReader(
                    assetManager.open(fileName)));
            String line;
            while ((line = bf.readLine()) != null) {
                stringBuilder.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return stringBuilder.toString();
    }

}

步驟六、在Activity中書寫業(yè)務(wù)邏輯代碼

public class Case46 extends AppCompatActivity {
    private Button btnAreaPicker;
    //省、市、區(qū)-列表
    private List<String> options1Items = new ArrayList<>();
    private List<List<String>> options2Items = new ArrayList<>();
    private List<List<List<String>>> options3Items = new ArrayList<>();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_case46);
        //初始化
        initView();
        //彈出選擇器
        getView();
        //填充數(shù)據(jù)
        initJsonData();
    }

    private void initView() {
        btnAreaPicker = findViewById(R.id.btnAreaPicker);
    }

    private void getView() {
        btnAreaPicker.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                areaPicker();
            }
        });
    }

    /**
     *  PickerView用法
     */
    private void areaPicker() {
        OptionsPickerView pvOptions = new OptionsPickerBuilder(this, new OnOptionsSelectListener() {
            @Override
            public void onOptionsSelect(int options1, int options2, int options3, View v) {
                String str = options1Items.get(options1) +
                        options2Items.get(options1).get(options2) +
                        options3Items.get(options1).get(options2).get(options3);
                ToastUtils.show(str);
            }
        })
                .setTitleText("城市選擇")
                .setDividerColor(Color.BLACK)
                .setTextColorCenter(Color.BLACK)
                .setContentTextSize(20)
                .setOutSideCancelable(false)
                .build();
        pvOptions.setPicker(options1Items, options2Items, options3Items);
        pvOptions.show();
    }

    /**
     *  解析數(shù)據(jù)
     */
    private void initJsonData() {
        String str = new GetJsonDataUtil().getJson(this, "province.json");
        List<ProviceBean> list = new Gson().fromJson(str, new TypeToken<List<ProviceBean>>() {
        }.getType());
        for (ProviceBean bean : list) {
            options1Items.add(bean.getName());
            List<String> city = new ArrayList<>();
            List<List<String>> area = new ArrayList<>();
            for (ProviceBean.CityBean cityBean : bean.getCity()) {
                city.add(cityBean.getName());
                area.add(cityBean.getArea());
            }
            options2Items.add(city);
            options3Items.add(area);
        }
    }
}

大功告成！