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
	@Override
	public boolean onCreate() {
		personsq =new PersonSQlite(getContext());
		return false;
	}

	@Override
	public 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");
		}
	}

	@Override
	public 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;
	}

	@Override
	public 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;
	}

	@Override
	public 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;
	}

	@Override
	public 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 {

	@Override
	protected 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>