android_70_content provider

项目一:自定义内容提供者

清单:

 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sg31.sgcontentprovider"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    
    // 单元测试 注意 targetPackage!!!!!!!!!!!  
	<instrumentation android:name="android.test.InstrumentationTestRunner"
    android:targetPackage="com.sg31.sgcontentprovider"
    ></instrumentation>


    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        
        // 单元测试
        <uses-library android:name="android.test.runner"/>
        
        <activity
            android:name=".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>
        
        <provider android:name=".UserProvider"
            android:authorities="com.sg31.contentprovider"
            android:exported="true"
            ></provider>
        
    </application>

</manifest>

 

 

 

 

 

 

自定义内容提供者:

 

package com.sg31.sgcontentprovider;

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 UserProvider extends ContentProvider {

	private SGOpenHelper oh;
	SQLiteDatabase db;

	// 创建uri匹配器对象
	static UriMatcher um = new UriMatcher(UriMatcher.NO_MATCH);
	// 检测其他用户传入的uri与匹配器定义好的uri中，哪条匹配
	static {
		um.addURI("com.sg31.contentprovider", "usertable", 1);// content://com.sg31.contentprovide/usertable
		um.addURI("com.sg31.contentprovider", "girltable", 2);// content://com.sg31.contentprovide/girltable
		um.addURI("com.sg31.contentprovider", "usertable/#", 3);// content://com.sg31.contentprovide/usertable/4
	}

	// 内容提供者创建时调用
	@Override
	public boolean onCreate() {
		oh = new SGOpenHelper(getContext());
		db = oh.getWritableDatabase();
		return false;
	}

	@Override
	public Cursor query(Uri uri, String[] projection, String selection,
			String[] selectionArgs, String sortOrder) {
		Cursor cursor = null;
		if (um.match(uri) == 1) {
			cursor = db.query("usertable", projection, selection, selectionArgs,
					null, null, sortOrder, null);
		} else if (um.match(uri) == 2) {
			cursor = db.query("girltable", projection, selection, selectionArgs,
					null, null, sortOrder, null);
		} else if (um.match(uri) == 3) {
			// 把uri末尾携带的数字取出来
			long id = ContentUris.parseId(uri);
			cursor = db.query("usertable", projection, "_id = ?",
					new String[] { id + "" }, null, null, sortOrder, null);
		} else {
			throw new IllegalArgumentException("uri又有问题哟亲么么哒");
		}
		return cursor;
	}

	@Override
	public String getType(Uri uri) {
		if (um.match(uri) == 1) {
			return "vnd.android.cursor.dir/usertable";
		} else if (um.match(uri) == 3) {
			return "vnd.android.cursor.item/usertable";
		}
		return null;
	}

	// 此方法供其他应用调用，用于往people数据库里插数据
	// values：由其他应用传入，用于封装要插入的数据
	// uri:内容提供者的主机名，也就是地址
	@Override
	public Uri insert(Uri uri, ContentValues values) {
		// 使用uri匹配器匹配传入的uri
		if (um.match(uri) == 1) {
			db.insert("usertable", null, values);

			// 发送数据改变的通知
			// uri:通知发送到哪一个uri上，所有注册在这个uri上的内容观察者都可以收到这个通知
			getContext().getContentResolver().notifyChange(uri, null);
		} else if (um.match(uri) == 2) {
			db.insert("girltable", null, values);

			getContext().getContentResolver().notifyChange(uri, null);
		} else {
			throw new IllegalArgumentException("uri有问题哟亲么么哒");
		}
		return uri;
	}

	@Override
	public int delete(Uri uri, String selection, String[] selectionArgs) {
		// 本来还要根据uri来判断的,但是这儿暂时直接写死
		int i = db.delete("usertable", selection, selectionArgs);
		return i;
	}

	@Override
	public int update(Uri uri, ContentValues values, String selection,
			String[] selectionArgs) {
		int i = db.update("usertable", values, selection, selectionArgs);
		return i;
	}

}

数据库操作类:

 

 

package com.sg31.sgcontentprovider;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class SGOpenHelper extends SQLiteOpenHelper {

	public SGOpenHelper(Context context) {
		super(context, "userdata.db", null, 1);
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		db.execSQL("create table usertable(_id integer primary key autoincrement, name char(10), money integer(20))");

	}

	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
		db.execSQL("create table girltable(_id integer primary key autoincrement, name char(10))");
	}

}

 

 

 

 

 

 

 

测试类:

 

package com.sg31.sgcontentprovider;

import android.test.AndroidTestCase;

public class SGTestCase extends AndroidTestCase {
	// 测计,必须是public的方法!!!  
    public void testAdd() {  
        // 断言
        SGOpenHelper oh = new SGOpenHelper(getContext());
		oh.getWritableDatabase();
    }  
}

 

 

 

 

 

 

 

 

 

项目二:访问内容提供者

 

布局:

 

<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: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="com.sg31.accesscontentprovider.MainActivity" 
    android:orientation="vertical"
    >

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="插入" 
        android:onClick="insertBtnClicked"
        />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="删除" 
        android:onClick="deleteBtnClicked"
        />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="修改" 
        android:onClick="updateBtnClicked"
        />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="查询" 
        android:onClick="selectBtnClicked"
        />

</LinearLayout>

 

 

 

 

 

控制器:

 

package com.sg31.accesscontentprovider;

import android.support.v7.app.ActionBarActivity;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;


public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }


    @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;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
    
    
    
    
    public void insertBtnClicked(View v){
        //通过内容提供者把数据插入另一个app的user数据库
        //拿到contentResolver
        ContentResolver cr = getContentResolver();
        ContentValues values = new ContentValues();
        values.put("name", "beyond");
        //    	values.put("money", "5267");
        //url:内容提供者的主机名
        //values:要插入的数据
        cr.insert(Uri.parse("content://com.sg31.contentprovider/usertable"), values);
        
    }
    
    public void deleteBtnClicked(View v){
        ContentResolver cr = getContentResolver();
        int i = cr.delete(Uri.parse("content://com.sg31.contentprovider"), "name = ?", new String[]{"beyond"});
        System.out.println(i);
    }
    public void updateBtnClicked(View v){
        ContentResolver cr = getContentResolver();
        ContentValues values = new ContentValues();
        values.put("name", "dnoyeb");
        int i = cr.update(Uri.parse("content://com.sg31.contentprovider"), values, "name = ?", new String[]{"beyond"});
        System.out.println(i);
    }
    
    public void selectBtnClicked(View v){
        ContentResolver cr = getContentResolver();
        Cursor cursor = cr.query(Uri.parse("content://com.sg31.contentprovider/usertable/4"), null, null, null, null);
        while(cursor.moveToNext()){
            String name = cursor.getString(1);
            String money = cursor.getString(2);
            System.out.println(name + ";" + money);
        }
    }
    
    
    
}