Android基础学习之Provider（内容提供器）

Provider是Android四大组件之一，是一种数据共享机制(封装数据的接口规范)。是一个数据库的代理，实现跨应用间的数据共享，类似于window服务本身不负责启动和关闭,多个应用可同时访问统一provider。

主要类：

ContentProvider 类

ContentProvider 对象将程序内部数据向其他程序公开

ContentResolver 类

其他程序通过ContentResolver 对象对程序内部数据进行CRUD操作

ContentProvider 分类：

1.使用别人的provider 比如电话本,短信,媒体 这些数据系统底层使用xxx.db数据库封装为ContentProvider 接口

2.应用创建的provider 程序员自定义的,可提供给别人使用

如何定义自己的provider

步骤:

1.继承ContentProvider 定义子类

2.重写6个方法(所有方法都需要uri,每个ContentProvider 都提供对外公共uri) ContentProvider 将共享数据定义为uri

public class MenusProvider extends ContentProvider{

@Override
public boolean onCreate() {
// 底层数据库初始化
return false;
}

@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
return null;
}

@Override //要实现该方法必须完成
//1.定义MIME类型
//2.定义URI字符串
//3.用urimather建立code和uri映射
//4.用code来映射不同MIEM类型
public String getType(Uri uri) {
// 返回MIME类型,一般用静态块来完成
return null;
}

@Override
public Uri insert(Uri uri, ContentValues values) {
return null;
}

@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
return 0;
}

@Override
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
return 0;
}
}

uri代表地址,解决如何表示数据的问题.

3.声明CONTENT_URI公共的静态常量,实现UriMathcer的绑定

当自定义provider需要告诉使用ContentProvider 的人用到那些uri

UriMatcher类 将uri和MIME绑定的

ContentUris类 将uri解析/生成

4.实现provider底层封装到sqlite框架中.

4.1 onCreat() 初始化数据库 SQLiteOpenHelper辅助类

4.2 provider重写提供CRUD操作方法,如何使用uri

如：

content://myfs.pub.menusprovider/menus/2

list={“menus”,”2”}

5.注册provider，在AndroidManifest.xml文件< application>< /application>标签中（四大组件都需要注册）

<provider
android:name="com.robin.myprovider.MenusProvider"
<!--Provider子类全名 -->
android:authorities="myfs.pub.menusprovider"
<!--指定授权者(自定义字符串) -->
android:exported="true"
<!-- 跨应用共享数据 设置为true默认为false
表示该provider能够被其他应用程序组件调用 -->
>< /provider>

6.测试provider

本地测试provider

远程测试provider

报错：

Installation error: INSTALL_FAILED_CONFLICTING_PROVIDER

表示系统中已经有同名的provider，调试时卸载重装即可。

使用->观察者模式

作用：监听ContentProvider 数据改变

ContentObserver 类

当ContentProvider 共享出来后,有时应用需要实时获得ContentProvider 共享数据的变化需要利用ContentObserver对象来实现。

实现步骤：

1.provider端的CRUD操作改变数据时调用resolver. notifyChange()方法

2.使用provider端要注册ContentObserver 对象

2.1 定义ContentObserver 子类重写onChange(boolean selfChange)方法

2.2 构造子类对象并注册给使用provider端的ContentResolver对象

如：cr.registerContentObserver(Menus.CONTENT_URI, notifyForDescendents, observer);

参数：

Menus.CONTENT_URI:监听CP的uri –> content://authority/menus

notifyForDescendents：true 表示该uri下所有的数据变化都监听

observer：false 表示只是监听uri数据变化

示例：

1.定义数据bean类

文件名Menus.java

package com.ql.providerdemo;

import android.net.Uri;

/**
* 定义provider需要的相关数据  MIME类型
* @author qinlang
*
*/
public class Menus {
// 以下定义provider的MIME类型常量
public static final String MIME_DIR_PREFIX = "vnd.android.cursor.dir";// MIME类型 多条
public static final String MIME_ITEM_PREFIX = "vnd.android.cursor.item";// 单条
//以上两条为android规定的
public static final String MIME_ITEM = "vnd.pub.menus";// 自定义MIME类型字符串
// 将固定前缀+自定义字符串生成两个类型
public static final String MIME_TYPE_SINGLE = MIME_ITEM_PREFIX + "/"
+ MIME_ITEM;
public static final String MIME_TYPE_MULTIPLE = MIME_DIR_PREFIX + "/"
+ MIME_ITEM;

// 用来定义uri常量 content://<authority>/<data path>/..../id
public static final String AUTHORITY = "myfs.pub.menusprovider";// 授权者 表示用哪个provider，要跟清单文件中一致
public static final String PATH_SINGLE = "menus/#"; // （menus：数据库表名）路径下单条记录 #代表数字id
public static final String PATH_MULTIPLE = "menus";// 路径下多条记录 数据库将对应表名
public static final String PATH_MULTIPLE_NAME = "menus/*"; // *代表文本 例如按名称访问等

// 组合成所需要的uri字符串
public static final String CONTENT_URI_STRING = "content://" + AUTHORITY
+ "/" + PATH_MULTIPLE;
// 将uri字符串转换为uri对象
public static final Uri CONTENT_URI = Uri.parse(CONTENT_URI_STRING);
// 以上就完成自定义provider所需的uri和MIME类型的定义

// 涉及sqlite底层实现的内容
public static final String CREAT_TABLE = "create table menus(id integer primary key autoincrement ,name varchar(50),price integer)";
public static final String DBNAME = "pub.db";//数据库名
public static final String TABLENAME = "menus";//表名
public static final int DB_VER = 1;//数据库版本，用于升级用

//常量字符串，对应数据库中的字段
public static final String KEY_ID = "id";
public static final String KEY_NAME = "name";
public static final String KEY_PRICE = "price";

public static final String[] COLUNMS = { KEY_ID, KEY_NAME, KEY_PRICE };

private int id;
private String name;
private int price;

public Menus() {
}

public Menus(String name, int price) {
this.name = name;
this.price = price;
}

@Override
public String toString() {
return "id:" + id + " | name:" + name + " | price:" + price;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getPrice() {
return price;
}

public void setPrice(int price) {
this.price = price;
}
}

2.创建ContentProvider的子类，内容提供类

文件名：MenusProvider.java

package com.ql.providerdemo;

import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;

public class MenusProvider extends ContentProvider {
// 构造一个matcher对象
private static final UriMatcher sURIMatcher = new UriMatcher(
UriMatcher.NO_MATCH);

// 定义code用来找对对应各种MIME类型的编码
private static final int MULTIPLE_MENUS = 1;
private static final int SINGLE_MENUS = 2;

// 静态块,在类加载时执行一次,将uri和code绑定起来,以便解析
static {
sURIMatcher.addURI(Menus.AUTHORITY, Menus.PATH_MULTIPLE, MULTIPLE_MENUS);
sURIMatcher.addURI(Menus.AUTHORITY, Menus.PATH_SINGLE, SINGLE_MENUS);
}

//数据库帮助类，用于创建表
static class DBOpenHelper extends SQLiteOpenHelper {

public DBOpenHelper(Context context, String name,
CursorFactory factory, int version) {
super(context, name, factory, version);
}

@Override
// 用db对象来创建表
public void onCreate(SQLiteDatabase db) {
db.execSQL(Menus.CREAT_TABLE);
}

@Override
//表的更新
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists " + Menus.TABLENAME);
db.execSQL(Menus.CREAT_TABLE);
}
}

private SQLiteDatabase sqdb;
private DBOpenHelper helper;

@Override
public boolean onCreate() {
Context context = getContext();//得到context对象
helper = new DBOpenHelper(context, Menus.DBNAME, null, Menus.DB_VER);//实例化数据库帮助类对象
sqdb = helper.getWritableDatabase();//得到数据库
if (sqdb == null) {
return false;
} else {
return true;
}
}

@Override
/**
* 数据查询
*/
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables(Menus.TABLENAME);
switch (sURIMatcher.match(uri)) {
case SINGLE_MENUS:
qb.appendWhere(Menus.KEY_ID + "=" + uri.getPathSegments().get(1));
break;
case MULTIPLE_MENUS:
break;
default:
break;
}
Cursor cursor = qb.query(sqdb, projection, selection, selectionArgs,
null, null, sortOrder);
return cursor;
}

@Override
/**
* 得到MIME类型
*/
public String getType(Uri uri) {
// 返回uri对应的MIME类型
int match = sURIMatcher.match(uri);
switch (match) {
case MULTIPLE_MENUS:
return Menus.MIME_TYPE_MULTIPLE;
case SINGLE_MENUS:
return Menus.MIME_TYPE_SINGLE;
default:
throw new IllegalArgumentException("Unknown uri:" + uri);
}
}

@Override
/**
* 插入操作
*/
public Uri insert(Uri uri, ContentValues values) {
long id = sqdb.insert(Menus.TABLENAME, null, values);
if (id > 0) {
Uri newUri = ContentUris.withAppendedId(uri, id);
return newUri;
} else {
throw new SQLException("fail to insert row into :" + uri);
}
}

@Override
/**
* 删除操作
*/
public int delete(Uri uri, String selection, String[] selectionArgs) {
int result = -1;
switch (sURIMatcher.match(uri)) {
case SINGLE_MENUS:
String id = uri.getPathSegments().get(1);
result = sqdb.delete(Menus.TABLENAME, Menus.KEY_ID + "=" + id,
selectionArgs);

break;
case MULTIPLE_MENUS:
result = sqdb.delete(Menus.TABLENAME, selection, selectionArgs);

default:
throw new IllegalArgumentException("Unknown uri:" + uri);
}
return result;
}

@Override
/**
* 更新操作
*/
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
int count = 0;
switch (sURIMatcher.match(uri)) {
case SINGLE_MENUS:
String id = uri.getPathSegments().get(1);// 从uri取出id字符串
count = sqdb.update(Menus.TABLENAME, values, Menus.KEY_ID + "="
+ id, selectionArgs);
break;
case MULTIPLE_MENUS:
count = sqdb.update(Menus.TABLENAME, values, selection,
selectionArgs);
break;
default:
throw new IllegalArgumentException("Unknown uri:" + uri);
}
return count;
}

}

3.在清单文件中添加权限和注册ContentProvider子类

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.ql.providerdemo"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="9"
android:targetSdkVersion="19" />

<!-- 添加自定义权限 -->
<permission
android:name="com.ql.provider.READ"
android:label="@string/app_name"
android:protectionLevel="normal"
></permission>

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<provider
android:name="com.ql.providerdemo.MenusProvider"
android:authorities="myfs.pub.menusprovider"
android:exported="true"
android:readPermission="com.ql.provider.READ" >
<!-- 指定授权者 -->
<!-- 给予其他应用程序只读取自己数据的权限 -->
</provider>

<activity
android:name="com.ql.providerdemo.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>

4.用于测试的Activity

4.1布局文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="${packageName}.${activityClass}" >

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >

<Button
android:id="@+id/btn_add"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="添加" />

<EditText
android:id="@+id/txt_addName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="输入名称" >

<requestFocus />
</EditText>

<EditText
android:id="@+id/txt_addPrice"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="输入单价" />
</LinearLayout>

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content" >

<Button
android:id="@+id/btn_delById"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="按ID删除" />

<EditText
android:id="@+id/txt_delId"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:hint="输入删除的ID" />

<Button
android:id="@+id/btn_delAll"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="删除全部" />
</LinearLayout>

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content" >

<Button
android:id="@+id/btn_queryById"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="按ID查询" />

<EditText
android:id="@+id/txt_queryId"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:hint="输入查询的ID" />

<Button
android:id="@+id/btn_queryAll"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="查询全部" />
</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >

<Button
android:id="@+id/btn_update"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="修改" />

<EditText
android:id="@+id/txt_updateId"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="输入要修改的ID" />

<EditText
android:id="@+id/txt_updataName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="名称" />

<EditText
android:id="@+id/txt_updataPrice"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="单价" />
</LinearLayout>

<ListView
android:id="@+id/listView1"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" >
</ListView>

</LinearLayout>

4.2java代码

public class MainActivity extends Activity implements OnClickListener {
private static final String TAG = "ql debug";
private ContentResolver cr;

private Button btn_add;
private Button btn_delAll;
private Button btn_delById;
private Button btn_update;
private Button btn_queryAll;
private Button btn_queryById;
private ListView listView;
private EditText txt_addName;
private EditText txt_addPrice;
private EditText txt_delId;
private EditText txt_queryId;
private EditText txt_updateId;
private EditText txt_updataName;
private EditText txt_updataPrice;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
listView = (ListView) findViewById(R.id.listView1);

txt_addName = (EditText) findViewById(R.id.txt_addName);
txt_addPrice = (EditText) findViewById(R.id.txt_addPrice);
txt_delId = (EditText) findViewById(R.id.txt_delId);
txt_queryId = (EditText) findViewById(R.id.txt_queryId);
txt_updateId = (EditText) findViewById(R.id.txt_updateId);
txt_updataName = (EditText) findViewById(R.id.txt_updataName);
txt_updataPrice = (EditText) findViewById(R.id.txt_updataPrice);

btn_add = (Button) findViewById(R.id.btn_add);
btn_delAll = (Button) findViewById(R.id.btn_delAll);
btn_delById = (Button) findViewById(R.id.btn_delById);
btn_update = (Button) findViewById(R.id.btn_update);
btn_queryAll = (Button) findViewById(R.id.btn_queryAll);
btn_queryById = (Button) findViewById(R.id.btn_queryById);
btn_add.setOnClickListener(this);
btn_delAll.setOnClickListener(this);
btn_delById.setOnClickListener(this);
btn_queryAll.setOnClickListener(this);
btn_queryById.setOnClickListener(this);
btn_update.setOnClickListener(this);

cr = getContentResolver(); //实例化ContentResolver 对象
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_add:
String name = txt_addName.getText().toString().trim();
String s_price = txt_addPrice.getText().toString().trim();
if ("".equals(name) || "".equals(s_price)) {
Toast.makeText(this, "输入不可为空！", Toast.LENGTH_SHORT).show();
}else {
int price = Integer.valueOf(s_price);
addData(name, price);
}
break;
case R.id.btn_delAll:
delAllData();
break;
case R.id.btn_delById:
String s_del_id = txt_delId.getText().toString().trim();
if (!"".equals(s_del_id)) {
int del_id = Integer.valueOf(s_del_id);
delById(del_id);
}
break;
case R.id.btn_update:
String s_updata_id = txt_updateId.getText().toString().trim();
String updata_name = txt_updataName.getText().toString().trim();
String s_updata_price = txt_updataPrice.getText().toString().trim();
if (!"".equals(s_updata_id)) {
int updata_id = Integer.valueOf(s_updata_id);
if ("".equals(updata_name) && "".equals(s_updata_price)) {
Toast.makeText(this, "没有项进行修改！", Toast.LENGTH_SHORT).show();
}else {
updateData(updata_id, updata_name, s_updata_price);
}
}
break;
case R.id.btn_queryAll:
queryAll();
break;
case R.id.btn_queryById:
String s_query_id = txt_queryId.getText().toString().trim();
if (!"".equals(s_query_id)) {
int query_id = Integer.valueOf(s_query_id);
queryById(query_id);
}
break;

default:
break;
}
}

private void updateData(int id, String name, String price) {
Menus mm = new Menus();
if (!"".equals(name)) {
mm.setName(name);
}
if (!"".equals(price)) {
int i_price = Integer.valueOf(price);
mm.setPrice(i_price);
}
Uri uri = Uri.parse(Menus.CONTENT_URI + "/" + id);// 定义要操作的uri
ContentValues values = new ContentValues();
values.put(Menus.KEY_NAME, mm.getName());
values.put(Menus.KEY_PRICE, mm.getPrice());
int result = cr.update(uri, values, null, null);
}

private void queryById(int id) {
Uri uri = Uri.parse(Menus.CONTENT_URI + "/" + id);
Cursor cursor = cr.query(uri, Menus.COLUNMS, null, null, null);
ArrayList<String> arr = new ArrayList<String>();
arr.add("ID\tNAME\tPRICE");
//      Log.e(TAG, "==单条查询==");
if (cursor != null) {
if (cursor.moveToFirst()) {
String s = cursor.getString(0) + "\t\t" + cursor.getString(1)
+ "\t\t" + cursor.getString(2);
//              Log.e(TAG, s);
arr.add(s);
}
}
listView.setAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, arr));
}

private void queryAll() {
Cursor cursor = cr.query(Menus.CONTENT_URI, Menus.COLUNMS, null, null,
null);
ArrayList<String> arr = new ArrayList<String>();
arr.add("ID\tNAME\tPRICE");
//      Log.e(TAG, "==查询所有==");
Log.d(TAG, "Is null:" + String.valueOf(cursor == null ? true : false));
if (cursor != null) {
if (cursor.moveToFirst()) {
do {
String s = cursor.getString(0) + "\t\t" + cursor.getString(1)
+ "\t\t" + cursor.getString(2);
arr.add(s);
//                  Log.e(TAG, s);
} while (cursor.moveToNext());
}
}
listView.setAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, arr));
}

private void delById(int id) {
Uri uri = Uri.parse(Menus.CONTENT_URI + "/" + id);// 定义要操作的uri
int result = cr.delete(uri, null, null);
Toast.makeText(this, result + "项删除完成！", Toast.LENGTH_SHORT).show();
}

private void delAllData() {
int result = cr.delete(Menus.CONTENT_URI, null, null);
Toast.makeText(this, result + "项删除完成！", Toast.LENGTH_SHORT).show();
}

private void addData(String name, int price) {

Menus[] mms = { new Menus(name, price)};

for (Menus m : mms) {
ContentValues cv = new ContentValues();
cv.put(Menus.KEY_NAME, m.getName());
cv.put(Menus.KEY_PRICE, m.getPrice());
Uri uri = cr.insert(Menus.CONTENT_URI, cv); // 最终
// cp.insert(url,values)
Log.d(TAG, "add data:" + uri.toString());
}
}
}

测试示例：

用于测试以上程序的内容提供者。

布局和bean一样，清单文件只添加了数据提供者给的读取权限

<!-- 添加读取应用程序的读取权限 -->
<uses-permission android:name="com.ql.provider.READ" />

活动添加了内容观察者对象

public class MainActivity extends Activity implements OnClickListener {
private static final String TAG = "ql debug";
private ContentResolver cr;

private Button btn_add;
private Button btn_delAll;
private Button btn_delById;
private Button btn_update;
private Button btn_queryAll;
private Button btn_queryById;
private ListView listView;
private EditText txt_addName;
private EditText txt_addPrice;
private EditText txt_delId;
private EditText txt_queryId;
private EditText txt_updateId;
private EditText txt_updataName;
private EditText txt_updataPrice;

/**
* 内容提供器观察者对象
* @author qinlang
*
*/
class MyContentObserver extends ContentObserver{

public MyContentObserver(Handler handler) {
super(handler);
}

@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
//          Log.e(TAG, "remote observer find content provider data change!!!");
queryAll();
}
}

MyContentObserver observer;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
listView = (ListView) findViewById(R.id.listView1);

txt_addName = (EditText) findViewById(R.id.txt_addName);
txt_addPrice = (EditText) findViewById(R.id.txt_addPrice);
txt_delId = (EditText) findViewById(R.id.txt_delId);
txt_queryId = (EditText) findViewById(R.id.txt_queryId);
txt_updateId = (EditText) findViewById(R.id.txt_updateId);
txt_updataName = (EditText) findViewById(R.id.txt_updataName);
txt_updataPrice = (EditText) findViewById(R.id.txt_updataPrice);

btn_add = (Button) findViewById(R.id.btn_add);
btn_delAll = (Button) findViewById(R.id.btn_delAll);
btn_delById = (Button) findViewById(R.id.btn_delById);
btn_update = (Button) findViewById(R.id.btn_update);
btn_queryAll = (Button) findViewById(R.id.btn_queryAll);
btn_queryById = (Button) findViewById(R.id.btn_queryById);
btn_add.setOnClickListener(this);
btn_delAll.setOnClickListener(this);
btn_delById.setOnClickListener(this);
btn_queryAll.setOnClickListener(this);
btn_queryById.setOnClickListener(this);
btn_update.setOnClickListener(this);

observer=new MyContentObserver(new Handler());
cr = getContentResolver();
//注册内容提供器观察者对象
cr.registerContentObserver(Menus.CONTENT_URI, true, observer);
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_add:
String name = txt_addName.getText().toString().trim();
String s_price = txt_addPrice.getText().toString().trim();
if ("".equals(name) || "".equals(s_price)) {
Toast.makeText(this, "输入不可为空！", Toast.LENGTH_SHORT).show();
}else {
int price = Integer.valueOf(s_price);
addData(name, price);
}
break;
case R.id.btn_delAll:
delAllData();
break;
case R.id.btn_delById:
String s_del_id = txt_delId.getText().toString().trim();
if (!"".equals(s_del_id)) {
int del_id = Integer.valueOf(s_del_id);
delById(del_id);
}
break;
case R.id.btn_update:
String s_updata_id = txt_updateId.getText().toString().trim();
String updata_name = txt_updataName.getText().toString().trim();
String s_updata_price = txt_updataPrice.getText().toString().trim();
if (!"".equals(s_updata_id)) {
int updata_id = Integer.valueOf(s_updata_id);
if ("".equals(updata_name) && "".equals(s_updata_price)) {
Toast.makeText(this, "没有项进行修改！", Toast.LENGTH_SHORT).show();
}else {
updateData(updata_id, updata_name, s_updata_price);
}
}
break;
case R.id.btn_queryAll:
queryAll();
break;
case R.id.btn_queryById:
String s_query_id = txt_queryId.getText().toString().trim();
if (!"".equals(s_query_id)) {
int query_id = Integer.valueOf(s_query_id);
queryById(query_id);
}
break;

default:
break;
}
}

private void updateData(int id, String name, String price) {
Menus mm = new Menus();
ContentValues values = new ContentValues();
if (!"".equals(name)) {
mm.setName(name);
values.put(Menus.KEY_NAME, mm.getName());
}
if (!"".equals(price)) {
int i_price = Integer.valueOf(price);
mm.setPrice(i_price);
values.put(Menus.KEY_PRICE, mm.getPrice());
}
Uri uri = Uri.parse(Menus.CONTENT_URI + "/" + id);// 定义要操作的uri

int result = cr.update(uri, values, null, null);
}

private void queryById(int id) {
Uri uri = Uri.parse(Menus.CONTENT_URI + "/" + id);
Cursor cursor = cr.query(uri, Menus.COLUNMS, null, null, null);
ArrayList<String> arr = new ArrayList<String>();
arr.add("ID\tNAME\tPRICE");
Log.e(TAG, "==单条查询==");
if (cursor != null) {
if (cursor.moveToFirst()) {
String s = cursor.getString(0) + "\t\t" + cursor.getString(1)
+ "\t\t" + cursor.getString(2);
//              Log.e(TAG, s);
arr.add(s);
}
}
listView.setAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, arr));
}

private void queryAll() {
Cursor cursor = cr.query(Menus.CONTENT_URI, Menus.COLUNMS, null, null,
null);
ArrayList<String> arr = new ArrayList<String>();
arr.add("ID\tNAME\tPRICE");
Log.e(TAG, "==查询所有==");
Log.d(TAG, "Is null:" + String.valueOf(cursor == null ? true : false));
if (cursor != null) {
if (cursor.moveToFirst()) {
do {
String s = cursor.getString(0) + "\t\t" + cursor.getString(1)
+ "\t\t" + cursor.getString(2);
arr.add(s);
//                  Log.e(TAG, s);
} while (cursor.moveToNext());
}
}
listView.setAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, arr));
}

private void delById(int id) {
Uri uri = Uri.parse(Menus.CONTENT_URI + "/" + id);// 定义要操作的uri
int result = cr.delete(uri, null, null);
Toast.makeText(this, result + "项删除完成！", Toast.LENGTH_SHORT).show();
}

private void delAllData() {
int result = cr.delete(Menus.CONTENT_URI, null, null);
Toast.makeText(this, result + "项删除完成！", Toast.LENGTH_SHORT).show();
}

private void addData(String name, int price) {

Menus[] mms = { new Menus(name, price)};

for (Menus m : mms) {
ContentValues cv = new ContentValues();
cv.put(Menus.KEY_NAME, m.getName());
cv.put(Menus.KEY_PRICE, m.getPrice());
Uri uri = cr.insert(Menus.CONTENT_URI, cv); // 最终
// cp.insert(url,values)
Log.d(TAG, "add data:" + uri.toString());
}
}
}