安卓开发：学生信息管理小程序

成品图

打开程序，实现添加学生，及时显示数据库内容,男女分别用相应的图片表示，点击垃圾桶可以删除这一行的学生，刷新数据，停留在刚才的位置：

1.activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    xmlns:android1="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="学生信息管理系统" />    <EditText         android1:id="@+id/name"       android:layout_width="match_parent"        android:layout_height="wrap_content"        android1:hint="请输入学生姓名" />   <RadioGroup       android1:orientation="horizontal"        android1:id="@+id/sex"        android1:layout_width="match_parent"        android1:layout_height="wrap_content"           >        <RadioButton            android1:id="@+id/male"            android1:layout_width="0dp"            android1:layout_weight="1"            android1:layout_height="wrap_content"            android1:checked="true"            android1:text="男" />        <RadioButton            android1:id="@+id/female"            android1:layout_weight="1"            android1:layout_width="0dp"            android1:layout_height="wrap_content"            android1:text="女" />    RadioGroup>   <Button         android1:id="@+id/saveInfo"        android:onClick="saveInfo"       android:layout_width="match_parent"       android:layout_height="wrap_content"        android1:text="保存"        />       <ListView            android1:id="@+id/lv"            android:layout_width="match_parent"            android:layout_height="match_parent"           >ListView>LinearLayout>

2. item.xml(显示数据库学生的信息)

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="horizontal"   >    <ImageView         android:id="@+id/iv_sex"        android:layout_width="25dp"        android:layout_height="25dp"         --     需要在drawable-hdpi 中添加男人标志图片 -->        android:src="@drawable/man"        />    <TextView         android:id="@+id/tv_name"        android:layout_toRightOf="@id/iv_sex"        android:gravity="center_vertical"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="姓名"        android:textSize="22sp"        android:textColor="#ff0000"        android:layout_marginLeft="20dp"        />    <ImageView         android:id="@+id/iv_delete"        android:layout_alignParentRight="true"        android:layout_marginRight="50dp"        android:layout_width="25dp"        android:layout_height="25dp"         --     需要在drawable-hdpi 中添加垃圾桶图片 -->        android:src="@drawable/delete"        />RelativeLayout>

3. MainActivity.java

package com.zt.studentsystemv2;import java.util.List;import com.zt.studentdbhelper.Student;import com.zt.studentdbhelper.StudentDao;import android.app.Activity;import android.os.Bundle;import android.text.TextUtils;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.Button;import android.widget.EditText;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.RadioButton;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity {    private EditText name;    private RadioButton male,female;    private ListView lv;    private Button save;//  private LinearLayout viewInfo;    private String stuName,sex;    StudentDao dao = new StudentDao(this, "student.db", null, 1);    boolean isStart=true;    private List stuInfo;    private MyAdapter myAdapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);  //      viewInfo = (LinearLayout) findViewById(R.id.info);        lv=(ListView) findViewById(R.id.lv);        refreshData();    }    private void init() {           name = (EditText) findViewById(R.id.name);        male = (RadioButton) findViewById(R.id.male);        female = (RadioButton) findViewById(R.id.female);        save = (Button) findViewById(R.id.saveInfo);        stuName = name.getText().toString().trim();        if (TextUtils.isEmpty(stuName)){            alter("姓名不能为空");            isStart=false;            return ;        }        sex = male.isChecked()?"男":"女";        isStart=true;    }    private void alter(String info) {        Toast.makeText(this, info, 5).show();    }    public void saveInfo(View v) {        init();        if (!isStart) return;        dao.add(stuName, sex);        alter("保存成功!");        refreshData();    }    private void refreshData() {        stuInfo = dao.find();        if (myAdapter==null){            myAdapter = new MyAdapter();            lv.setAdapter(myAdapter);        }else{            //通知数据适配器更新数据,而不是new出来新的数据适配器            myAdapter.notifyDataSetChanged();        }    }    class MyAdapter extends BaseAdapter{        @Override        public View getView(final int position, View convertView, ViewGroup parent) {            View item = null;            if (convertView==null){                //把一个布局xml文件转化成view对象                item = View.inflate(MainActivity.this,R.layout.item, null);            }else{                //利用回收的对象                item = convertView;            }            ImageView sex=(ImageView) item.findViewById(R.id.iv_sex);            Student stu = stuInfo.get(position);            if ("男".equals(stu.getSex())){                sex.setImageResource(R.drawable.man);            }else{                sex.setImageResource(R.drawable.woman);            }            TextView tv = (TextView) item.findViewById(R.id.tv_name);            tv.setText(stu.getName());            ImageView delete = (ImageView) item.findViewById(R.id.iv_delete);            delete.setOnClickListener(new OnClickListener() {                                   @Override                public void onClick(View v) {                    Student stu = stuInfo.get(position);                    //从数据库删除数据                    dao.delete(stu.getName(), stu.getSex());                    alter("删除成功!");                    //更新ui                    refreshData();                }            });            return item;        }        @Override        public int getCount() {            return stuInfo.size();        }        @Override        public long getItemId(int position) {            // TODO Auto-generated method stub            return 0;        }        @Override        public Object getItem(int position) {            // TODO Auto-generated method stub            return null;        }    }}

4.sqlLite数据库的操作:

Student.java:

package com.zt.studentdbhelper;public class Student {    private String name;    private String sex;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }}

StudentDBHelper.java:

package com.zt.studentdbhelper;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;import android.util.Log;public class StudentDBHelper extends SQLiteOpenHelper {    public StudentDBHelper(Context context, String name, CursorFactory factory,            int version) {        super(context, name, factory, version);    }    @Override    public void onCreate(SQLiteDatabase db) {        db.execSQL("create table student(_id integer primary key autoincrement,name varchar(20),sex varchar(4) check(sex in ('男','女')))");    }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {        Log.i("MainActivity","建表完成！");    }}

StudentDao:

package com.zt.studentdbhelper;import java.util.ArrayList;import java.util.List;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;public class StudentDao {    private StudentDBHelper helper;    public StudentDao(Context context, String name, CursorFactory factory,            int version) {        helper=new StudentDBHelper(context, name, factory, version);    }    /**     * 添加一个学生     * @param name     * @param phone     */    public void add(String name,String sex) {        SQLiteDatabase  sqlHelper = helper.getWritableDatabase();        sqlHelper.execSQL("insert into student(name,sex)values(?,?)", new Object[]{name,sex});        sqlHelper.close();    }    public void delete(String name,String sex) {        SQLiteDatabase  sqlHelper = helper.getWritableDatabase();        sqlHelper.execSQL("delete from student where name =? and sex=?", new Object[]{name,sex});        sqlHelper.close();    }    public List  find() {        List list = new ArrayList();        SQLiteDatabase  sqlHelper = helper.getReadableDatabase();        Cursor  cur = sqlHelper.rawQuery("select name,sex from student where name is not null and  sex is not null", null);        boolean result = cur.moveToNext();        while (result){            Student stu= new Student();            stu.setName(cur.getString(0));            stu.setSex(cur.getString(1));            list.add(stu);            result= cur.moveToNext();        }        cur.close();        sqlHelper.close();        return list;    }}

查看数据库：

将/sdk/platform-tools加入环境变量；
cmd下使用adb shell ，cd 进入相应包，进入数据库目录
输入sqLite3 student.db，select * from student;

成品图

1.activity_main.xml:

2. item.xml(显示数据库学生的信息)

3. MainActivity.java

4.sqlLite数据库的操作:

查看数据库：

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