在模拟器上显示数据库中提取的信息的列表
时间有限，就不写注释了，看得懂的就看，看不懂的到晚上查资料创建一个db的androiproject项目
同时创建一个MainActivity的Acitivity.java的类
新建com.gohighsoft.db包
MainActivity.java:
package com.gohighsoft.db;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
public class MainActivity extends Activity {
private final static String TAG = "aa";
private PersonService personService;
private ListView listView;
// private PersonService personService;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
personService = new PersonService(this);// 前十条数据
List<Person> persons = personService.getScrollData(0, 100);
listView = (ListView) findViewById(R.id.personList);
List<HashMap<String, String>> data = new ArrayList<HashMap<String, String>>();
HashMap<String, String> title = new HashMap<String, String>();
title.put("personid", "编号");
title.put("name", "姓名");
title.put("age", "年龄");
data.add(title);
for (Person person : persons) {
HashMap<String, String> map = new HashMap<String, String>();
map.put("personid", String.valueOf(person.getId()));
map.put("name", person.getName());
map.put("age", String.valueOf(person.getAge()));
data.add(map);
}
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this, data,
R.layout.personitem,
new String[] { "personid", "name", "age" }, new int[] {
R.id.personid, R.id.name, R.id.age });
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
ListView listView = (ListView) parent;
HashMap<String, String> itemData = (HashMap<String, String>) listView
.getItemAtPosition(position);
String personid = itemData.get("personid");
String name = itemData.get("name");
String age = itemData.get("age");
Log.i(TAG, "className" + view.getClass().getName());
// 打印view的类名
Log.i("TAG", "personid=" + personid + ",name=" + name + ",age="
+ age);
Log.i(TAG, "result=" + (position == id));
}
});
}
}
在Layout文件夹下创建personitem.xml的界面配置代码：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content" android:layout_height="wrap_content">
<TextView android:layout_width="60px" android:layout_height="60px"
android:id="@+id/personid" />
<TextView android:layout_width="160px" android:layout_height="wrap_content"
android:layout_toRightOf="@id/personid" android:layout_alignTop="@id/personid"
android:gravity="center_horizontal" android:id="@+id/name" />
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content" android:layout_toRightOf="@id/name"
android:layout_alignTop="@id/name" android:id="@+id/age" />
</LinearLayout>
新建一个工具类DataBaseHaler.java:
package com.gohighsoft.db;
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 DataBaseHaler extends SQLiteOpenHelper {
private static final String NAME = "sharp.db";// 。db可有可无
private static final int version = 1;// 版本号不能为0
public DataBaseHaler(Context context) {
super(context, NAME, null, version);
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.i("aa","1111111111111");
db.execSQL("CREATE TABLE person(personid integer primary key autoincrement,name varchar(20),age integer)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVewsion) {
Log.i("aa","22222222222222");
db.execSQL("DROP TABLE IF EXISTS PERSON");
onCreate(db);
}
}
新近一个PersonService.java的服务类:
package com.gohighsoft.db;
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
public class PersonService {
private DataBaseHaler databaseHelper;
private Context context;
public PersonService(Context context) {
this.context = context;
databaseHelper = new DataBaseHaler(context);
}
public void savesTrannces(Person person) {
Log.i("aa", "4444444444444");
SQLiteDatabase db = databaseHelper.getWritableDatabase();
db.beginTransaction();// 开始事务
try {
for(int i=0;i<100;i++){
db.execSQL("insert into person(name,age) values(?,?)",
new Object[] { person.getName(), person.getAge() });
}
db.execSQL("insert into personww(namedd,age) values(?,?)",
new Object[] { person.getName(), person.getAge() });
db.setTransactionSuccessful();
} catch (Exception e) {
//db.endTransaction();// 事务结束;
Log.i("aa","wwwwwwwwwwwwwwwwwwwwwwwww");
}
db.endTransaction();// 事务结束;
Log.i("aa", "55555555555555555555");
}
public void save1(Person person) {
SQLiteDatabase db = databaseHelper.getWritableDatabase();
db.beginTransaction();// 开始事务
Log.i("aa", "uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu");
try {
db.setTransactionSuccessful();
db.execSQL("insert into person(name,age) values('Tom',21)");
} catch (Exception e) {
Log.i("aa", "trttttttttttttttttttttttttttttttttttttttttttttt");
}
db.endTransaction();// 事务结束;
}
public void save2(Person person) {
SQLiteDatabase db = databaseHelper.getWritableDatabase();
db.beginTransaction();// 开始事务
Log.i("aa", "uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu");
try {
db.setTransactionSuccessful();
for(int i=0;i<100;i++){
db.execSQL("insert into person(name,age) values(?,?)",
new Object[] { person.getName(), person.getAge() });
}
} catch (Exception e) {
Log.i("aa", "trttttttttttttttttttttttttttttttttttttttttttttt");
}
db.endTransaction();// 事务结束;
}
public void update(Person person) {
SQLiteDatabase db = databaseHelper.getWritableDatabase();
db.execSQL(
"update person set name=?,age=? where personid=?",
new Object[] { person.getName(), person.getAge(),
person.getId() });
}
public Person find(Integer id) {
SQLiteDatabase db = databaseHelper.getReadableDatabase();
Cursor cursor = db.rawQuery(
"select personid,name,age from person where personid=?",
new String[] { String.valueOf(id) });
if (cursor.moveToNext()) {
Person person = new Person();
person.setId(cursor.getInt(cursor.getColumnIndex("personid")));
person.setName(cursor.getString(1));
person.setAge(cursor.getInt(2));
return person;
}
cursor.close();
return null;
}
public void delete(Integer id) {
SQLiteDatabase db = databaseHelper.getWritableDatabase();
db.execSQL("delete fro person where personid=?", new Object[] { id });
}
public List<Person> getScrollData(int firstResult, int maxResult) {
List<Person> persons = new ArrayList<Person>();
SQLiteDatabase db = databaseHelper.getReadableDatabase();
Cursor cursor = db.rawQuery(
"select personid,name,age from person limit ?,?",
new String[] { String.valueOf(firstResult),
String.valueOf(maxResult) });// firstResult开始索引
while (cursor.moveToNext()) {// maxResult每页获取的记录数
Log.i("aa", "333333333333");
Person person = new Person();
person.setId(cursor.getInt(cursor.getColumnIndex("personid")));
person.setName(cursor.getString(1));
person.setAge(cursor.getInt(2));
persons.add(person);
}
cursor.close();
return persons;
}
public long getCount() {
SQLiteDatabase db = databaseHelper.getReadableDatabase();
Cursor cursor = db.rawQuery("select count(*) from person", null);
// 没有占位符参数的话，直接用null
cursor.moveToFirst();
Long count = cursor.getLong(0);
cursor.close();
return count;
}
}
实体类传递数据：Person.java
package com.gohighsoft.db;
public class Person {
private Integer id;
private String name;
private Integer age;
public Person() {
};
public Person(String name, Integer age) {
this.name = name;
this.age = age;
}
public Integer getId(){
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String toString() {
return "Person ";
}
}
最后main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView android:id="@+id/personList" android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</LinearLayout>
好了到此为止算是完成了，直接运行MainActivity.java就可以了
看不懂的自己上网去查去，不再详细的解释了.
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