Android利用Spinner从数据库中读取数据并实现2级互动

来源：互联网发布：尼康官方调焦软件编辑：程序博客网时间：2024/06/04 06:33

以前学习Java EE的时候，经常会遇到一些下拉表单进行联动的实例。

例子：假如一个公司有三个部门，括号里面是职位

人力资源部（员工关系主管，招聘主管）

财务部（财务总监、财务部经理、审计主管）

生产技术部（程序员，设计师，架构师）

我们将做个两级联动的spinner，当我第一级选择不同的部门，第二级将显示不同的职位

SQLiteOpenHelper类：

package org.jian.database;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;public class DBHelper extends SQLiteOpenHelper {    private static final String DB_NAME = "martin.db" ;    private static final int VERSION = 3 ;        SQLiteDatabase db ;    private String job_sql = "CREATE TABLE IF NOT EXISTS job(" +                             "_id INTEGER PRIMARY KEY ," +                             "jobname VARCHAR(20) ," +                             "did INTEGER" +                             ")" ;    private String dept_sql = "CREATE TABLE IF NOT EXISTS dept(" +                              "_id INTEGER PRIMARY KEY ," +                              "deptname VARCHAR(20)" +                              ")" ;        public DBHelper(Context context) {        super(context, DB_NAME, null, VERSION);    }    @Override    public void onCreate(SQLiteDatabase db) {        this.db = db ;        db.execSQL(job_sql) ;        db.execSQL(dept_sql) ;    }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {            }}

用sql插入数据（在sqlite里，用adb进入）：

INSERT INTO job VALUES(null ,"员工关系主管" , 1) ;INSERT INTO job VALUES(null ,"招聘主管 " , 1) ;INSERT INTO job VALUES(null ,"财务总监" , 2) ;INSERT INTO job VALUES(null ,"财务部经理" , 2) ;INSERT INTO job VALUES(null ,"审计主管" , 2) ;INSERT INTO job VALUES(null ,"程序员" , 3) ;INSERT INTO job VALUES(null ,"设计师" , 3) ;INSERT INTO job VALUES(null ,"架构师" , 3) ;INSERT INTO dept VALUES(null ,"人力资源部" ) ;INSERT INTO dept VALUES(null ,"财务部" ) ;INSERT INTO dept VALUES(null ,"生产技术部" ) ;

处理数据的类：

package org.jian.service;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import org.jian.database.DBHelper;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;public class Database {    private DBHelper dbHelper;    public Database(Context context) {        dbHelper = new DBHelper(context);    }    /**     * 查询数据库，返回一个Map 这个Map包括 1，spinner需要显示的字符串，以及其所组成的map 2，spinner需要显示的字符串     *      * @return     */    public Map<Integer, List<?>> getDepts() {        String sql = "SELECT _id, deptname FROM dept";   //获取部门Id号与部门的名称        SQLiteDatabase db = null;        Cursor c = null;        Map<Integer, List<?>> DeptData = new HashMap<Integer, List<?>>();        try {            db = dbHelper.getWritableDatabase(); // 获取数据库            c = db.rawQuery(sql, null);            List<Map<String, Integer>> collegeList1 = new ArrayList<Map<String, Integer>>();            List<String> collegeList2 = new ArrayList<String>();            while (c.moveToNext()) {                Map<String, Integer> provinceMap = new HashMap<String, Integer>(); // 这个HashMap主要是用来白村学院的信息以及他的id                String name = new String(c.getBlob(1), "GBK");                provinceMap.put(name, c.getInt(0));                collegeList1.add(provinceMap); // 保存这个Map                collegeList2.add(name); // 保存这个名字的列表            }            DeptData.put(0, collegeList1);            DeptData.put(1, collegeList2);        } catch (Exception e) {            e.printStackTrace();        } finally {            if (c != null) {                c.close();            }            if (db != null) {                db.close();            }        }        return DeptData;    }    /**     * 返回一个List     * 包含job的字符串所组成的数组     * @param id     * @return     */    public List<String> getJobById(int id) {        String sql = "SELECT jobname FROM job WHERE did = " + id;        SQLiteDatabase db = null;        Cursor c = null;        List<String> jobList = null;        try {            db = dbHelper.getWritableDatabase();            c = db.rawQuery(sql, null);            jobList = new ArrayList<String>();            while (c.moveToNext()) {                String jobName = new String(c.getBlob(0),"GBK") ;  //解决乱码                jobList.add(jobName);            }        } catch (Exception ex) {            ex.printStackTrace();        } finally {            if (c != null) {                c.close();            }            if (db != null) {                db.close();            }        }        return jobList;    }}

界面设计XML:spinner.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="请选择你的部门" />    <Spinner        android:id="@+id/dept"        android:layout_width="wrap_content"        android:layout_height="wrap_content" />    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="请选择你的职位" />    <Spinner        android:id="@+id/job"        android:layout_width="wrap_content"        android:layout_height="wrap_content" /></LinearLayout>

Activity类：

package org.jian.activity;import java.util.ArrayList;import java.util.List;import java.util.Map;import org.jian.service.Database;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.AdapterView.OnItemSelectedListener;import android.widget.ArrayAdapter;import android.widget.Spinner;import com.example.spinner.R;public class MainActivity extends Activity {    List deptList = new ArrayList();    List deptData = new ArrayList();    List jobList = new ArrayList();       Spinner job;    Spinner dept;    Database db;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.spanner);        job = (Spinner) findViewById(R.id.job);        dept = (Spinner) findViewById(R.id.dept);        db = new Database(getApplicationContext());        Map<Integer, List<?>> data = database.getDepts();// 得到数据库数据        deptList = data.get(1);        deptData = data.get(0);        ArrayAdapter deptAdapter = new ArrayAdapter(MainActivity.this,                android.R.layout.simple_spinner_item, deptList);        deptAdapter                .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); // 样式        dept.setAdapter(deptAdapter);        dept.setOnItemSelectedListener(itemSelectedListener);    }    private OnItemSelectedListener itemSelectedListener = new OnItemSelectedListener() {        @Override        public void onItemSelected(AdapterView<?> parent, View view,                int position, long id) {            Spinner spdept = (Spinner) parent;            String seldept = (String) spdept.getItemAtPosition(position);            ArrayAdapter jobAdapter = null;            Map<String, Integer> data = (Map<String, Integer>) deptData                    .get(position);// 根据id，返回本门号的信息            int pid = data.get(seldept);// 得到部门号的id            List<String> jobList = db.getJobById(pid); // 根据id查得工作类型的一个List            jobAdapter = new ArrayAdapter(MainActivity.this,                    android.R.layout.simple_spinner_item, jobList);            jobAdapter                    .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);            job.setAdapter(jobAdapter);            job.setOnItemSelectedListener(jobSelectedListener);        }        @Override        public void onNothingSelected(AdapterView<?> parent) {        }    };    String selectedJob = null;    private OnItemSelectedListener jobSelectedListener = new OnItemSelectedListener() {        @Override        public void onItemSelected(AdapterView<?> parent, View view,                int position, long id) {            Spinner spjob = (Spinner) parent;            selectedJob = (String) spjob.getItemAtPosition(position);        }        @Override        public void onNothingSelected(AdapterView<?> parent) {        }    };}

运行结果：

当我选择部门为：财务部时：

工作职位出现的为：

0 0