1.布局文件 activity_main.xml
主要view对象为listView 必须设置width height :matchParent 优化性能
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>
2.数据显示的样式文件item.xml
分为两个TextView 并列显示name 和 age
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<TextView
android:id="@+id/tv_name"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
/>
<TextView
android:id="@+id/tv_age"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
/>
</LinearLayout>
3.DBHelper.java 继承SQLiteOpenHelper 创建数据库和表
package com.example.day13_ex_sqlite;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class DBHelper extends SQLiteOpenHelper {
public DBHelper(Context context){
super(context,"test.db", null,1);
}
public DBHelper(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase arg0) {
// TODO Auto-generated method stub
//创建表user
String sql="create table user(_id integer primary key autoincrement,name text,age integer)";
arg0.execSQL(sql);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}
4.main.xml菜单文件 用于在菜单上添加固定数据
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item
android:id="@+id/action_settings"
android:orderInCategory="100"
android:showAsAction="always"
android:title="添加固定数据"/>
</menu>
5.MainActivity.java
package com.example.day13_ex_sqlite;
import java.util.Currency;
import android.os.Bundle;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
DBHelper db;
SQLiteDatabase sd;
SimpleCursorAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
db=new DBHelper(this);
sd=db.getWritableDatabase();
//insert();插入成功
ListView lv=(ListView) findViewById(R.id.lv);
Cursor cs=query();
adapter=new SimpleCursorAdapter(this,R.layout.item, cs,new String[]{"name","age"},new int[]{R.id.tv_name,R.id.tv_age},0);
lv.setAdapter(adapter);
//listView 设置点击事件
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
Toast.makeText(MainActivity.this,"您点击了位置"+arg2, 0).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
//菜单点击事件
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// TODO Auto-generated method stub
if(item.getItemId()==R.id.action_settings){
String name="乔峰";
int age=34;
String sql="insert into user(name,age) values('"+name+"','"+age+"')";
sd.execSQL(sql);
Toast.makeText(this,"添加数据成功!",0).show();
adapter.changeCursor(query());
adapter.notifyDataSetChanged();
return true;
}
return super.onOptionsItemSelected(item);
}
//插入数据
public void insert(){
for(int i=0;i<10;i++){
String name="张"+i+"丰";
int age=i;
String sql="insert into user(name,age)values('"+name+"','"+i+"')";
sd.execSQL(sql);
}
}
//查询数据 返回游标对象
public Cursor query(){
String sql="select * from user";
Cursor cs = sd.rawQuery(sql,null);
return cs;
}
}
随时随地看视频
