1.需求分析
1.1 问题定义
(1)使用Android Studio建立通讯录。用SQLite操作API完成对学生通讯录的添加(insert)、删除(delete)、更新(update)、查询(query),并使用SimpleAdapter配置ListView显示学生信息展示出来。
(2)用ListView做应用商城app。由于通信录的信息显示和应用商城都是对ListView的使用,在此对应用商城的实现不再赘述,在最后附上结果截图。
1.2 功能描述
对学生通讯录进行添加、删除、修改、查询的操作,并将数据库可视化。
Figure 1 用例图
1.3 技术要点
(1)帮助类SQLiteOpenHelper及数据库的创建
添加预定义构造函数,重写onCreate()方法和onUpdate()方法。创建和打开数据库,需要new一个帮助类的实现类。
(2)SQLite操作API
insert、delete、update、query
(3)数据库的可视化
适配器和ListView的使用
2.概要设计
2.1 系统体系结构
Figure 2 体系结构图
2.2 界面设计
Figure 3 界面预览
1.将图片背景资源导入项目中res\drawable文件夹下;
2.编写项目中res\layout\activity_main.xml文件,主体采用相对布局,
3.添加、删除、修改、查询四个按钮用LinearLayout(horizontal);EditText控件用来输入学生姓名和电话;TextView控件标注姓名和电话;ListView显示学生信息。
4.编写list_item.xml文件来设计表的显示界面。
3.详细设计
3.1数据库的创建StudentDBOpenHelper
package com.example.a15676.addressbook;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.content.Context;
import android.os.Build;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
//创建存储学生信息的数据库
public class StudentDBOpenHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME= "mydb";//库名
public static final String TABLE_NAME= "friends"; //表名
public static final int DATABASE_VERSION=1;
public static final int FRIENDS= 1;
public static final int FRIENDS_ID=2;
// 加下划线表示该字段不由用户输入
//对应于表friends的三个字段,public static final StringID=" id";
//其他字段
public static final String ID="_id";
public static final String NAME= "name";
public static final String PHONE="phone";
public StudentDBOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, name, factory, version);
}
@Override//数据表结构的初始化
public void onCreate(SQLiteDatabase db) {
System.out.print("onCreate()被调用");
db.execSQL("CREATE TABLE "+TABLE_NAME+"(_id integer primary key autoincrement,"+"name varchar(20),phone varchar(20)"+")");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
System.out.println("onUpgrade()数据库被升级了");
db.execSQL("DROP TABLE "+ TABLE_NAME); //先删除
onCreate(db); //后创建
}
}
3.2 MainActivity
package com.example.a15676.addressbook;
import android.annotation.SuppressLint;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
import android.widget.AdapterView;
import android.widget.SimpleAdapter;
import android.widget.AdapterView.OnItemClickListener;
public class MainActivity extends AppCompatActivity {
private EditText et_name;
private EditText et_phone;
private ArrayList<Map<String, Object>> data;
private SQLiteDatabase db;
private ListView listview;
private String selId;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_name = findViewById(R.id.et_name);
et_phone = findViewById(R.id.et_phone);
listview = findViewById(R.id.listView);
Button addBtn = findViewById(R.id.bt_add);
Button updBtn = findViewById(R.id.bt_modify);
Button delBtn = findViewById(R.id.bt_del);
Button selBtn=findViewById(R.id.bt_sel);
addBtn.setOnClickListener(new Button.OnClickListener() {
@Override
public void onClick(View v) {
dbAdd();
dbFindAll();
}
//StudentDBOpenHelper helper=new StudentDBOpenHelper(this,"Student.db",null,1);
});
updBtn.setOnClickListener(new Button.OnClickListener() {
@Override
public void onClick(View v) {
dbUpdate();
dbFindAll();
}
});
delBtn.setOnClickListener(new Button.OnClickListener() {
@Override
public void onClick(View v) {
dbDel();
dbFindAll();
}
});
selBtn.setOnClickListener(new Button.OnClickListener() {
@Override
public void onClick(View v) {
//dbDel();
dbFindAll();
// showList();
// select();
}
});
///
StudentDBOpenHelper dbHelper = new StudentDBOpenHelper(this, StudentDBOpenHelper.DATABASE_NAME, null, 1);
db = dbHelper.getWritableDatabase();
data = new ArrayList<>();
dbFindAll();
//listview的点击事件监听返回点击的是哪行数据
listview.setOnItemClickListener(new OnItemClickListener() {
@SuppressWarnings("unchecked")
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Map<String,Object>listItem=(Map<String,Object>)listview.getItemAtPosition(position);
et_name.setText((String)listItem.get("name"));
et_phone.setText((String)listItem.get("phone"));
selId=(String)listItem.get("_id");
Toast.makeText(getApplicationContext(),"选择的id是:"+selId,Toast.LENGTH_SHORT).show();
}
});
}
protected void dbDel(){
//String where="name="+et_name.getText().toString().trim();
int i=db.delete("friends","name=?",new String[]{et_name.getText().toString()});
if(i>0) Toast.makeText(getApplicationContext(),"数据删除成功!",Toast.LENGTH_SHORT).show();
else Toast.makeText(getApplicationContext(),"数据删除失败!",Toast.LENGTH_SHORT).show();
}
//设置simpleAdapter来在list_view中显示表数据
private void showList(){
SimpleAdapter listAdapter = new SimpleAdapter(this, data, R.layout.list_item, new String[]{"_id", "name", "phone"}, new int[]{R.id.tv_id, R.id.tv_name, R.id.tv_phone});
listview.setAdapter(listAdapter);
}
protected void dbUpdate(){
ContentValues values=new ContentValues();
values.put("phone",et_phone.getText().toString().trim());
int i=db.update("friends",values,"name=?",new String[]{et_name.getText().toString()});
Log.e("jjj","修改了好了数据");
if(i>0) Toast.makeText(getApplicationContext(),"数据更新成功!",Toast.LENGTH_SHORT).show();
else Toast.makeText(getApplicationContext(),"数据更新失败!",Toast.LENGTH_SHORT).show();
}
protected void dbAdd(){
ContentValues values=new ContentValues();
values.put("name",et_name.getText().toString().trim());
values.put("phone",et_phone.getText().toString().trim());
long ll=db.insert(StudentDBOpenHelper.TABLE_NAME,null,values);
if(ll==-1) Toast.makeText(getApplicationContext(),"数据插入失败!",Toast.LENGTH_SHORT).show();
else Toast.makeText(getApplicationContext(),"数据插入成功!",Toast.LENGTH_SHORT).show();
}
protected void dbFindAll(){
data.clear();
@SuppressLint("Recycle") Cursor cursor = db.rawQuery("select * from friends ", null);
Map<String, Object> item = new HashMap<>();
item.put("_id","序号"); item.put("name","姓名"); item.put("phone","电话");
data.add(item);
cursor.moveToFirst();
while(!cursor.isAfterLast()){
String id= cursor.getString(0);
String name= cursor.getString(1);
String phone= cursor.getString(2);
item =new HashMap<>();
item.put("_id",id);
item.put("name",name);
item.put("phone",phone);
data.add(item);
cursor.moveToNext();
}
showList();
}
}
/* public void add(View v){
SQLiteDatabase db=helper.getWritableDatabase();
ContentValues values=new ContentValues();
values.put("name",et_name.getText().toString());
values.put("phone",et_phone.getText().toString());
Long row=db.insert("Studentinfo",null,values);
Toast.makeText(this,"数据添加成功",Toast.LENGTH_SHORT).show();
db.close();
}
public void update(View v){
SQLiteDatabase db=helper.getWritableDatabase();
ContentValues values=new ContentValues();
//values.put("name",et_name.getText().toString());
values.put("phone",et_phone.getText().toString());
int number=db.update("Studentinfo",values,"name=?",new String[]{et_name.getText().toString()});
System.out.print("修改了"+number+"条数据");
Log.e("jjj","修改了"+number+"条数据");
Toast.makeText(this,"数据修改成功",Toast.LENGTH_SHORT).show();
db.close();
}
public void delete(View v){
SQLiteDatabase db=helper.getWritableDatabase();
// Long row=db.insert("Studentinfo",null,values);
long number=db.delete("Studentinfo","name=?",new String[]{et_name.getText().toString()});
System.out.print("删除了"+number+"条数据");
Toast.makeText(this,"数据删除成功",Toast.LENGTH_SHORT).show();
db.close();
}
private ListView lv;
public void select(View v){
// SQLiteDatabase db=helper.getReadableDatabase();
// Long row=db.insert("Studentinfo",null,values);
Cursor cursor=db.query("Studentinfo",null,null,null,null,null,null);
cursor.close();
Log.e("jjj","chadaole了条数据");
// lv.findViewById(R.id.lv);
// lv.setAdapter(array_adapter);
}
//读取通讯录的全部的联系人
//需要先在raw_contact表中遍历id,并根据id到data表中获取数据
/* public void select(){
//uri = content://com.android.contacts/contacts
SQLiteDatabase db=helper.getReadableDatabase();
Cursor cursor = db.rawQuery("select * from Studentinfo", null);
List<Student> studentinfos=new ArrayList<Student>();
int num=0;
while(cursor.moveToNext()){
Student student=new Student();
student.setId(cursor.getInt(cursor.getColumnIndex("_id")));
student.setName(cursor.getString(cursor.getColumnIndex("name")));
student.setPhone(cursor.getString(cursor.getColumnIndex("phone")));
num++;
studentinfos.add(student);
//student=null;
}
cursor.close();
db.close();
Log.e("dsdiuihfisduhfuic查出来", num+"条");
for(Student p:studentinfos){ System.out.println(p.toString()); }
Log.i("Contacts", "wan");
}*/
3.3 Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.a15676.addressbook">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
3.4activity_main
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
android:background="@drawable/h"
tools:context=".MainActivity">
<LinearLayout
android:id="@+id/A"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="50dp"
android:orientation="vertical"
android:layout_alignParentLeft="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="20dp"
android:layout_marginRight="30dp"
android:orientation="horizontal">
<TextView
android:id="@+id/textView2"
android:layout_width="170dp"
android:layout_height="50dp"
android:layout_weight="1"
android:textSize="20sp"
android:paddingLeft="20dp"
android:gravity="center_horizontal"
android:textColor="#ff000000"
android:text="姓名:" />
<EditText
android:id="@+id/et_name"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_weight="1"
android:ems="20"
android:textColor="#ff000000"
android:textSize="20sp" />
</LinearLayout>
<View
android:layout_width="match_parent"
android:layout_height="5dp"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="20dp"
android:layout_marginRight="30dp"
android:orientation="horizontal">
<TextView
android:id="@+id/textView3"
android:layout_width="170dp"
android:layout_height="50dp"
android:gravity="center_horizontal"
android:ems="20"
android:paddingLeft="20dp"
android:textSize="20sp"
android:layout_weight="1"
android:textColor="#ff000000"
android:text="电话:" />
<EditText
android:id="@+id/et_phone"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_weight="1"
android:ems="20"
android:inputType="phone"
android:textColor="#ff000000"
android:textSize="20sp" />
</LinearLayout>
</LinearLayout>
<View
android:layout_width="match_parent"
android:layout_height="5dp"
android:background="#11000000" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/B"
android:layout_below="@+id/A"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:orientation="horizontal">
<Button
android:id="@+id/bt_add"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="添加" />
<Button
android:id="@+id/bt_modify"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="修改" />
<Button
android:id="@+id/bt_del"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="删除" />
<Button
android:id="@+id/bt_sel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="查询" />
</LinearLayout>
<ListView
android:id="@+id/listView"
android:layout_below="@+id/B"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</RelativeLayout>
3.5list_item
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:orientation="horizontal"
android:layout_height="match_parent">
<TextView
android:id="@+id/tv_id"
android:layout_width="100dp"
android:textSize="20sp"
android:textColor="#ff000000"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
/>
<TextView
android:id="@+id/tv_name"
android:layout_width="120dp"
android:textSize="20sp"
android:textColor="#ff000000"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
/>
<TextView
android:id="@+id/tv_phone"
android:textSize="20sp"
android:textColor="#ff000000"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
/>
</LinearLayout>
4.系统运行结果
4.1 APP初始界面
运行app,可在虚拟机上看到如下界面:
Figure 4 初始界面
4.2 添加功能
输入:“zhangsan”“156798236”点击“添加”按钮,会弹出消息框“数据插入成功”,并在ListView中显示该条信息。如图6所示,
4.3 修改功能
把电话改为111,并点击“修改”按钮,则会弹出消息框“数据更新成功”,在listview中显示更新后的信息。如图7所示
4.3 删除功能
先选中一行信息,会弹出消息框“选择的id是:1”,这时点击删除按钮,就会把id=1的这一行信息删除。如图9所示,zhangsan这条信息已经没有了。
Figure 8 删除
4.4 查询功能
点击查询就会显示所有的信息。
Figure 9 查询
4.5 应用商城