内容提供者

内容提供者：PersonDBProvider:

package com.zhangli.db;import com.zhangli.shujuku.PersonSQlite;import android.content.ContentProvider;import android.content.ContentUris;import android.content.ContentValues;import android.content.UriMatcher;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.net.Uri;public class PersonDBProvider extends ContentProvider {//定义一个uri的匹配器用于匹配uri,如果路径不满足条件返回-1（NO_MATCH）private static UriMatcher matcher=new UriMatcher(UriMatcher.NO_MATCH);private static final int INSERT=1;private static final int DELETE=2;private static final int UPDATE=3;private static final int QUERY=4;private static final int QUERYONE=5;private PersonSQlite personsq; static{//添加一组匹配规则matcher.addURI("com.zhangli.db.personprovider", "insert", INSERT);matcher.addURI("com.zhangli.db.personprovider", "delete", DELETE);matcher.addURI("com.zhangli.db.personprovider", "update", UPDATE);matcher.addURI("com.zhangli.db.personprovider", "query", QUERY);matcher.addURI("com.zhangli.db.personprovider", "query/#", QUERYONE);}//content://com.zhangli.db.personprovider/insert  添加的操作//content://com.zhangli.db.personprovider/delete  删除//content://com.zhangli.db.personprovider/update  更新//content://com.zhangli.db.personprovider/query   查询//当内容提供者被创建的时候调用适合数据的初始化@Overridepublic boolean onCreate() {personsq =new PersonSQlite(getContext());return false;}@Overridepublic Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {if(matcher.match(uri)==QUERY){//返回查询的结果集SQLiteDatabase db=personsq.getReadableDatabase();Cursor cursor=db.query("person", projection, selection,selectionArgs, null, null,sortOrder);return cursor;}else if(matcher.match(uri)==QUERYONE){long id=ContentUris.parseId(uri);SQLiteDatabase db=personsq.getReadableDatabase();Cursor cursor=db.query("person", projection, "id=?",new String[]{id+""}, null, null,sortOrder);return cursor;}else{throw new IllegalArgumentException("路径不匹配，不能执行查询操作");}}@Overridepublic String getType(Uri uri) {if(matcher.match(uri)==QUERY){//返回查询的结果集//返回多条数据return "vnd.android.cursor.dir/persons" ;}else if(matcher.match(uri)==QUERYONE){//返回多条数据return "vnd.android.cursor.item/persons";}return null;}@Overridepublic Uri insert(Uri uri, ContentValues values) {if(matcher.match(uri)==INSERT){//返回添加的结果集SQLiteDatabase db=personsq.getWritableDatabase();db.insert("person", null, values);}else{throw new IllegalArgumentException("路径不匹配，不能执行添加操作");}return null;}@Overridepublic int delete(Uri uri, String selection, String[] selectionArgs) {if(matcher.match(uri)==DELETE){//返回删除的结果集SQLiteDatabase db=personsq.getWritableDatabase();db.delete("person", selection, selectionArgs);}else{throw new IllegalArgumentException("路径不匹配，不能执行删除操作");}return 0;}@Overridepublic int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {if(matcher.match(uri)==UPDATE){//返回修改的结果集SQLiteDatabase db=personsq.getWritableDatabase();db.update("person", values, selection, selectionArgs);}else{throw new IllegalArgumentException("路径不匹配，不能执行修改操作");}return 0;}}

另外创建一个项目

MainAcitivity:

package com.example.other;import android.app.Activity;import android.content.ContentResolver;import android.content.ContentValues;import android.database.Cursor;import android.net.Uri;import android.os.Bundle;import android.view.View;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);}public void click(View view){//得到中间人ContentResolver resolver=getContentResolver();Uri uri=Uri.parse("content://com.zhangli.db.personprovider/query/10");Cursor cursor=resolver.query(uri, null, null, null, null);while(cursor.moveToNext()){String name =cursor.getString(cursor.getColumnIndex("name"));String number=cursor.getString(cursor.getColumnIndex("number"));System.out.print("name:"+name+",number:"+number);}cursor.close();}public void delete(View view){ContentResolver resolver=getContentResolver();Uri uri=Uri.parse("content://com.zhangli.db.personprovider/delete");resolver.delete(uri,"name=?",new String[]{"狂奔的第0奶牛"} );}public void update(View view){ContentResolver resolver=getContentResolver();Uri uri=Uri.parse("content://com.zhangli.db.personprovider/update");ContentValues values=new ContentValues();values.put("number","110");resolver.update(uri, values, "name=?", new String[]{"狂奔的第1奶牛"});}public void insert(View view){ContentResolver resolver=getContentResolver();Uri uri=Uri.parse("content://com.zhangli.db.personprovider/insert");ContentValues values=new ContentValues();values.put("number","99999");values.put("name", "骑着野猪的奶牛");resolver.insert(uri, values);}}

配置清单：

activity_main.xml:

<LinearLayout 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:orientation="vertical"    tools:context="com.example.other.MainActivity" >    <Button        android:onClick="insert"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="添加db数据" />        <Button        android:onClick="delete"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="删除db数据" />        <Button        android:onClick="update"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="修改db数据" />        <Button        android:onClick="click"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="查询db数据" /></LinearLayout>