【黑马Android】(04)数据库的创建和sql语句增删改查/LinearLayout展示列表数据/ListView的使用和BaseAdater/内容提供者创建...-白红宇

【黑马Android】(04)数据库的创建和sql语句增删改查/LinearLayout展示列表数据/ListView的使用和BaseAdater/内容提供者创建...

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发布时间：2019-06-09

本文共 29669 字，大约阅读时间需要 98 分钟。

数据库的创建和sql语句增删改查

1. 载入驱动.

2. 连接数据库.

3. 操作数据库.

创建表:

create table person(

_id integer primary key,

name varchar(20),

age integer

);

加入: insert into person(name, age) values('lisi', 19);

删除: delete from person where _id = 1;

改动: update person set name = '李四' where name = '王五';

查询全部: select * from person;

查询单条: select * from person where name = 'zhangsan';

SQLiteExpert3, pc上的工具软件。

package com.itheima28.sqlitedemo.dao;import java.util.ArrayList;import java.util.List;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import com.itheima28.sqlitedemo.db.PersonSQLiteOpenHelper;import com.itheima28.sqlitedemo.entities.Person;public class PersonDao {	private PersonSQLiteOpenHelper mOpenHelper;	// 数据库的帮助类对象	public PersonDao(Context context) {		mOpenHelper = new PersonSQLiteOpenHelper(context);	}		/**	 * 加入到person表一条数据	 * @param person	 */	public void insert(Person person) {		SQLiteDatabase db = mOpenHelper.getWritableDatabase();		if(db.isOpen()) {	// 假设数据库打开, 运行加入的操作						// 运行加入到数据库的操作			db.execSQL("insert into person(name, age) values(?

, ?);", new Object[]{person.getName(), person.getAge()}); db.close(); // 数据库关闭 } } /** * 更据id删除记录 * @param id */ public void delete(int id) { SQLiteDatabase db = mOpenHelper.getWritableDatabase(); // 获得可写的数据库对象 if(db.isOpen()) { // 假设数据库打开, 运行加入的操作 db.execSQL("delete from person where _id = ?;", new Integer[]{id}); db.close(); // 数据库关闭 } } /** * 依据id找到记录, 而且改动姓名 * @param id * @param name */ public void update(int id, String name) { SQLiteDatabase db = mOpenHelper.getWritableDatabase(); if(db.isOpen()) { // 假设数据库打开, 运行加入的操作 db.execSQL("update person set name = ? where _id = ?;", new Object[]{name, id}); db.close(); // 数据库关闭 } } public List<Person> queryAll() { SQLiteDatabase db = mOpenHelper.getReadableDatabase(); // 获得一个仅仅读的数据库对象 if(db.isOpen()) { Cursor cursor = db.rawQuery("select _id, name, age from person;", null); if(cursor != null && cursor.getCount() > 0) { List<Person> personList = new ArrayList<Person>(); int id; String name; int age; while(cursor.moveToNext()) { id = cursor.getInt(0); // 取第0列的数据 id name = cursor.getString(1); // 取姓名 age = cursor.getInt(2); // 取年龄 personList.add(new Person(id, name, age)); } db.close(); return personList; } db.close(); } return null; } /** * 依据id查询人 * @param id * @return */ public Person queryItem(int id) { SQLiteDatabase db = mOpenHelper.getReadableDatabase(); // 获得一个仅仅读的数据库对象 if(db.isOpen()) { Cursor cursor = db.rawQuery("select _id, name, age from person where _id = ?

;", new String[]{id + ""}); if(cursor != null && cursor.moveToFirst()) { int _id = cursor.getInt(0); String name = cursor.getString(1); int age = cursor.getInt(2); db.close(); return new Person(_id, name, age); } db.close(); } return null; } }

package com.itheima28.sqlitedemo.db;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;import android.util.Log;/** * @author andong * 数据库帮助类, 用于创建和管理数据库的. */public class PersonSQLiteOpenHelper extends SQLiteOpenHelper {	private static final String TAG = "PersonSQLiteOpenHelper";	/**	 * 数据库的构造函数	 * @param context	 * 	 * name 数据库名称	 * factory 游标project	 * version 数据库的版本 不能够小于1	 */	public PersonSQLiteOpenHelper(Context context) {		super(context, "itheima28.db", null, 2);	}	/**	 * 数据库第一次创建时回调此方法.	 * 初始化一些表	 */	@Override	public void onCreate(SQLiteDatabase db) {		// 操作数据库		String sql = "create table person(_id integer primary key, name varchar(20), age integer);";		db.execSQL(sql);		// 创建person表	}	/**	 * 数据库的版本更新时回调此方法,	 * 更新数据库的内容(删除表, 加入表, 改动表)	 */	@Override	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {		if(oldVersion == 1 && newVersion == 2) {			Log.i(TAG, "数据库更新啦");			// 在person表中加入一个剩余金额列balance			db.execSQL("alter table person add balance integer;");		}	}}

package com.itheima28.sqlitedemo.entities;public class Person {	private int id;	private String name;	private int age;	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 getAge() {		return age;	}	public void setAge(int age) {		this.age = age;	}	public Person() {		super();		// TODO Auto-generated constructor stub	}	public Person(int id, String name, int age) {		super();		this.id = id;		this.name = name;		this.age = age;	}	@Override	public String toString() {		return "Person [id=" + id + ", name=" + name + ", age=" + age + "]";	}}

package com.itheima28.sqlitedemo.test;import java.util.List;import com.itheima28.sqlitedemo.dao.PersonDao;import com.itheima28.sqlitedemo.db.PersonSQLiteOpenHelper;import com.itheima28.sqlitedemo.entities.Person;import android.database.SQLException;import android.database.sqlite.SQLiteDatabase;import android.test.AndroidTestCase;import android.util.Log;public class TestCase extends AndroidTestCase {	private static final String TAG = "TestCase";	public void test() {		// 数据库什么时候创建		PersonSQLiteOpenHelper openHelper = new PersonSQLiteOpenHelper(getContext());				// 第一次连接数据库时创建数据库文件. onCreate会被调用		openHelper.getReadableDatabase();	}		public void testInsert() {		PersonDao dao = new PersonDao(getContext());				dao.insert(new Person(0, "冠希", 28));	}		public void testDelete() {		PersonDao dao = new PersonDao(getContext());		dao.delete(1);	}	public void testUpdate() {		PersonDao dao = new PersonDao(getContext());		dao.update(3, "凤姐");	}	public void testQueryAll() {		PersonDao dao = new PersonDao(getContext());		List
     
       personList = dao.queryAll();				for (Person person : personList) {			Log.i(TAG, person.toString());		}	}	public void testQueryItem() {		PersonDao dao = new PersonDao(getContext());		Person person = dao.queryItem(4);		Log.i(TAG, person.toString());	}		public void testTransaction() {		PersonSQLiteOpenHelper openHelper = new PersonSQLiteOpenHelper(getContext());		SQLiteDatabase db = openHelper.getWritableDatabase();				if(db.isOpen()) {						try {				// 开启事务				db.beginTransaction();								// 1. 从张三账户中扣1000块钱				db.execSQL("update person set balance = balance - 1000 where name = 'zhangsan';");								// ATM机, 挂掉了.				// int result = 10 / 0;								// 2. 向李四账户中加1000块钱				db.execSQL("update person set balance = balance + 1000 where name = 'lisi';");								// 标记事务成功				db.setTransactionSuccessful();			} finally {				// 停止事务				db.endTransaction();			}			db.close();		}	}		public void testTransactionInsert() {		PersonSQLiteOpenHelper openHelper = new PersonSQLiteOpenHelper(getContext());		SQLiteDatabase db = openHelper.getWritableDatabase();				if(db.isOpen()) {						// 1. 记住当前的时间			long start = System.currentTimeMillis();						// 2. 開始加入数据			try {				db.beginTransaction();				for (int i = 0; i < 10000; i++) {					db.execSQL("insert into person(name, age, balance) values('wang" + i + "', " + (10 + i) + ", " + (10000 + i) + ")");				}				db.setTransactionSuccessful();			} finally {				db.endTransaction();			}						// 3. 记住结束时间, 计算耗时时间			long end = System.currentTimeMillis();						long diff = end - start;			Log.i(TAG, "耗时: " + diff + "毫秒");						db.close();		}	}}

使用api方式查询数据库和sqlite3工具

adb shell

package com.itheima28.sqlitedemo.dao;import java.util.ArrayList;import java.util.List;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.util.Log;import com.itheima28.sqlitedemo.db.PersonSQLiteOpenHelper;import com.itheima28.sqlitedemo.entities.Person;public class PersonDao2 {	private static final String TAG = "PersonDao2";	private PersonSQLiteOpenHelper mOpenHelper;	// 数据库的帮助类对象	public PersonDao2(Context context) {		mOpenHelper = new PersonSQLiteOpenHelper(context);	}		/**	 * 加入到person表一条数据	 * @param person	 */	public void insert(Person person) {		SQLiteDatabase db = mOpenHelper.getWritableDatabase();		if(db.isOpen()) {	// 假设数据库打开, 运行加入的操作						ContentValues values = new ContentValues();			values.put("name", person.getName());		// key作为要存储的列名, value对象列的值			values.put("age", person.getAge());			long id = db.insert("person", "name", values);			Log.i(TAG, "id: " + id);						db.close();	// 数据库关闭		}	}		/**	 * 更据id删除记录	 * @param id	 */	public void delete(int id) {		SQLiteDatabase db = mOpenHelper.getWritableDatabase();	// 获得可写的数据库对象		if(db.isOpen()) {	// 假设数据库打开, 运行加入的操作						String whereClause = "_id = ?";			String[] whereArgs = {id + ""};			int count = db.delete("person", whereClause, whereArgs);			Log.i(TAG, "删除了: " + count + "行");			db.close();	// 数据库关闭		}	}		/**	 * 依据id找到记录, 而且改动姓名	 * @param id	 * @param name	 */	public void update(int id, String name) {		SQLiteDatabase db = mOpenHelper.getWritableDatabase();		if(db.isOpen()) {	// 假设数据库打开, 运行加入的操作			ContentValues values = new ContentValues();			values.put("name", name);						int count  = db.update("person", values, "_id = ?", new String[]{id + ""});			Log.i(TAG, "改动了: " + count + "行");						db.close();	// 数据库关闭		}	}		public List
     
       queryAll() {		SQLiteDatabase db = mOpenHelper.getReadableDatabase();	// 获得一个仅仅读的数据库对象		if(db.isOpen()) {			String[] columns = {"_id", "name", "age"};	// 须要的列			String selection = null;	// 选择条件, 给null查询全部			String[] selectionArgs = null;	// 选择条件的參数, 会把选择条件中的? 替换成数据中的值			String groupBy = null;	// 分组语句  group by name			String having = null;	// 过滤语句			String orderBy = null;	// 排序						Cursor cursor = db.query("person", columns, selection, selectionArgs, groupBy, having, orderBy);						int id;			String name;			int age;			if(cursor != null && cursor.getCount() > 0) {				List
      
        personList = new ArrayList
       
        ();								while(cursor.moveToNext()) {	// 向下移一位, 知道最后一位, 不能够往下移动了, 停止.					id = cursor.getInt(0);					name = cursor.getString(1);					age = cursor.getInt(2);										personList.add(new Person(id, name, age));				}								db.close();				return personList;			}			db.close();		}		return null;	}		/**	 * 依据id查询人	 * @param id	 * @return	 */	public Person queryItem(int id) {		SQLiteDatabase db = mOpenHelper.getReadableDatabase();	// 获得一个仅仅读的数据库对象		if(db.isOpen()) {			String[] columns = {"_id", "name", "age"};	// 须要的列			String selection = "_id = ?

"; // 选择条件, 给null查询全部 String[] selectionArgs = {id + ""}; // 选择条件的參数, 会把选择条件中的? 替换成数据中的值 String groupBy = null; // 分组语句 group by name String having = null; // 过滤语句 String orderBy = null; // 排序 Cursor cursor = db.query("person", columns, selection, selectionArgs, groupBy, having, orderBy); if(cursor != null && cursor.moveToFirst()) { // cursor对象不为null, 而且能够移动到第一行 int _id = cursor.getInt(0); String name = cursor.getString(1); int age = cursor.getInt(2); db.close(); return new Person(_id, name, age); } db.close(); } return null; } }

package com.itheima28.sqlitedemo.test;import java.util.List;import android.test.AndroidTestCase;import android.util.Log;import com.itheima28.sqlitedemo.dao.PersonDao2;import com.itheima28.sqlitedemo.db.PersonSQLiteOpenHelper;import com.itheima28.sqlitedemo.entities.Person;public class TestCase2 extends AndroidTestCase {	private static final String TAG = "TestCase";	public void test() {		// 数据库什么时候创建		PersonSQLiteOpenHelper openHelper = new PersonSQLiteOpenHelper(getContext());				// 第一次连接数据库时创建数据库文件. onCreate会被调用		openHelper.getReadableDatabase();	}		public void testInsert() {		PersonDao2 dao = new PersonDao2(getContext());		dao.insert(new Person(0, "zhouqi", 88));	}		public void testDelete() {		PersonDao2 dao = new PersonDao2(getContext());		dao.delete(8);	}	public void testUpdate() {		PersonDao2 dao = new PersonDao2(getContext());		dao.update(3, "fengjie");	}	public void testQueryAll() {		PersonDao2 dao = new PersonDao2(getContext());		List
     
       personList = dao.queryAll();				for (Person person : personList) {			Log.i(TAG, person.toString());		}	}	public void testQueryItem() {		PersonDao2 dao = new PersonDao2(getContext());		Person person = dao.queryItem(4);		Log.i(TAG, person.toString());	}}

事务的操作

事务:

update person set balance = balance - 100 where name = 'lisi';

update person set balance = balance + 100 where name = 'zhangsan';

// 开启事务

db.beginTransaction();

// 标记事务成功

db.setTransactionSuccessful();

// 停止事务

db.endTransaction();

public void testTransaction() {		PersonSQLiteOpenHelper openHelper = new PersonSQLiteOpenHelper(getContext());		SQLiteDatabase db = openHelper.getWritableDatabase();				if(db.isOpen()) {						try {				// 开启事务				db.beginTransaction();								// 1. 从张三账户中扣1000块钱				db.execSQL("update person set balance = balance - 1000 where name = 'zhangsan';");								// ATM机, 挂掉了.				// int result = 10 / 0;								// 2. 向李四账户中加1000块钱				db.execSQL("update person set balance = balance + 1000 where name = 'lisi';");								// 标记事务成功				db.setTransactionSuccessful();			} finally {				// 停止事务				db.endTransaction();			}			db.close();		}	}		public void testTransactionInsert() {		PersonSQLiteOpenHelper openHelper = new PersonSQLiteOpenHelper(getContext());		SQLiteDatabase db = openHelper.getWritableDatabase();				if(db.isOpen()) {						// 1. 记住当前的时间			long start = System.currentTimeMillis();						// 2. 開始加入数据			try {				db.beginTransaction();				for (int i = 0; i < 10000; i++) {					db.execSQL("insert into person(name, age, balance) values('wang" + i + "', " + (10 + i) + ", " + (10000 + i) + ")");				}				db.setTransactionSuccessful();			} finally {				db.endTransaction();			}						// 3. 记住结束时间, 计算耗时时间			long end = System.currentTimeMillis();						long diff = end - start;			Log.i(TAG, "耗时: " + diff + "毫秒");						db.close();		}	}

LinearLayout展示列表数据

package com.itheima28.sqlitedemo;import java.util.List;import com.itheima28.sqlitedemo.dao.PersonDao;import com.itheima28.sqlitedemo.entities.Person;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.View;import android.widget.LinearLayout;import android.widget.TextView;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                LinearLayout llList = (LinearLayout) findViewById(R.id.ll_list);                PersonDao dao = new PersonDao(this);        List
     
       personList = dao.queryAll();                if(personList != null) {	        TextView tv;	        for (Person person : personList) {				// 向线性布局中加入一个textview	        	tv = new TextView(this);	        	tv.setText(person.toString());	        	tv.setTextSize(18);	        		        	llList.addView(tv);			}        }    }    @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;    }    }

ListView的使用和BaseAdater

package com.itheima28.sqlitedemo;import java.util.List;import com.itheima28.sqlitedemo.dao.PersonDao;import com.itheima28.sqlitedemo.entities.Person;import android.os.Bundle;import android.app.Activity;import android.util.Log;import android.view.Menu;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.TextView;public class MainActivity extends Activity {    private List
     
       personList;	@Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                ListView mListView = (ListView) findViewById(R.id.listview);                PersonDao dao = new PersonDao(this);        personList = dao.queryAll();                // 把view层对象ListView和控制器BaseAdapter关联起来        mListView.setAdapter(new MyAdapter());    }    /**     * @author andong     * 数据适配器     */    class MyAdapter extends BaseAdapter {    	private static final String TAG = "MyAdapter";		/**    	 * 定义ListView的数据的长度    	 */		@Override		public int getCount() {			return personList.size();		}		@Override		public Object getItem(int position) {			// TODO Auto-generated method stub			return null;		}		@Override		public long getItemId(int position) {			// TODO Auto-generated method stub			return 0;		}		/**		 * 此方法返回的是ListView的列表中某一行的View对象		 * position 当前返回的view的索引位置		 * convertView 缓存对象		 * parent 就是ListView对象		 */		@Override		public View getView(int position, View convertView, ViewGroup parent) {								TextView tv = null;									if(convertView != null) {		// 推断缓存对象是否为null,  不为null时已经缓存了对象				Log.i(TAG, "getView: 复用缓存" + position);				tv = (TextView) convertView;			} else {	// 等于null, 说明第一次显示, 新创建				Log.i(TAG, "getView: 新建" + position);				tv = new TextView(MainActivity.this);			}						tv.setTextSize(25);						Person person = personList.get(position); // 获得指定位置的数据, 进行对TextView的绑定						tv.setText(person.toString());						return tv;		}    	    }}

package com.itheima28.sqlitedemo;import java.util.List;import com.itheima28.sqlitedemo.dao.PersonDao;import com.itheima28.sqlitedemo.entities.Person;import android.os.Bundle;import android.app.Activity;import android.util.Log;import android.view.LayoutInflater;import android.view.Menu;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.TextView;public class MainActivity2 extends Activity {    private List
     
       personList;	@Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                ListView mListView = (ListView) findViewById(R.id.listview);                PersonDao dao = new PersonDao(this);        personList = dao.queryAll();                // 把view层对象ListView和控制器BaseAdapter关联起来        mListView.setAdapter(new MyAdapter());    }    /**     * @author andong     * 数据适配器     */    class MyAdapter extends BaseAdapter {    	private static final String TAG = "MyAdapter";		/**    	 * 定义ListView的数据的长度    	 */		@Override		public int getCount() {			return personList.size();		}		@Override		public Object getItem(int position) {			// TODO Auto-generated method stub			return null;		}		@Override		public long getItemId(int position) {			// TODO Auto-generated method stub			return 0;		}		/**		 * 此方法返回的是ListView的列表中某一行的View对象		 * position 当前返回的view的索引位置		 * convertView 缓存对象		 * parent 就是ListView对象		 */		@Override		public View getView(int position, View convertView, ViewGroup parent) {			View view = null;						if(convertView == null) {				// 布局填充器对象, 用于把xml布局转换成view对象				LayoutInflater inflater = MainActivity2.this.getLayoutInflater();				view = inflater.inflate(R.layout.listview_item, null);			} else {				view = convertView;			}						// 给view中的姓名和年龄赋值			TextView tvName = (TextView) view.findViewById(R.id.tv_listview_item_name);			TextView tvAge = (TextView) view.findViewById(R.id.tv_listview_item_age);						Person person = personList.get(position);						tvName.setText("姓名: " + person.getName());			tvAge.setText("年龄: " + person.getAge());			return view;		}    	    }}

listview_item.xml

其它两种绑定ListView数据的方式

listview_item.xml

package com.itheima28.simpleadapterdemo;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.widget.ArrayAdapter;import android.widget.ListView;import android.widget.SimpleAdapter;public class MainActivity extends Activity {	@Override	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);				ListView mListView = (ListView) findViewById(R.id.listview);				List
      
       > data = new ArrayList
       
        
         >();				Map
         
           map = new HashMap
          
           (); map.put("name", "张三1"); map.put("icon", R.drawable.f007); data.add(map); map = new HashMap
           
            (); map.put("name", "张三2"); map.put("icon", R.drawable.f007); data.add(map); map = new HashMap
            
             (); map.put("name", "张三3"); map.put("icon", R.drawable.f007); data.add(map); map = new HashMap
             
              (); map.put("name", "张三4"); map.put("icon", R.drawable.f007); data.add(map); map = new HashMap
              
               (); map.put("name", "张三5"); map.put("icon", R.drawable.f007); data.add(map); SimpleAdapter adapter = new SimpleAdapter( this, // 上下文 data, // listView绑定的数据 R.layout.listview_item, // listview的子条目的布局的id new String[]{"name", "icon"}, // data数据中的map集合里的key new int[]{R.id.tv_name, R.id.iv_icon}); // resource 中的id mListView.setAdapter(adapter); } @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; }}

内容提供者创建

package com.itheima28.sqlitedemo.providers;import com.itheima28.sqlitedemo.db.PersonSQLiteOpenHelper;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 PersonContentProvider extends ContentProvider {		private static final String AUTHORITY = "com.itheima28.sqlitedemo.providers.PersonContentProvider";	private static final int PRESON_INSERT_CODE = 0;	// 操作person表加入的操作的uri匹配码	private static final int PERSON_DELETE_CODE = 1;	private static final int PERSON_UPDATE_CODE = 2;	private static final int PERSON_QUERY_ALL_CODE = 3;	private static final int PERSON_QUERY_ITEM_CODE = 4;		private static UriMatcher uriMatcher;	private PersonSQLiteOpenHelper mOpenHelper;		// person表的数据库帮助对象		static {		uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);				// 加入一些uri(分机号)				// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/insert		uriMatcher.addURI(AUTHORITY, "person/insert", PRESON_INSERT_CODE);				// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/delete		uriMatcher.addURI(AUTHORITY, "person/delete", PERSON_DELETE_CODE);		// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/update		uriMatcher.addURI(AUTHORITY, "person/update", PERSON_UPDATE_CODE);				// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/queryAll		uriMatcher.addURI(AUTHORITY, "person/queryAll", PERSON_QUERY_ALL_CODE);				// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/query/#		uriMatcher.addURI(AUTHORITY, "person/query/#", PERSON_QUERY_ITEM_CODE);	}	@Override	public boolean onCreate() {		mOpenHelper = new PersonSQLiteOpenHelper(getContext());		return true;	}	@Override	public Cursor query(Uri uri, String[] projection, String selection,			String[] selectionArgs, String sortOrder) {		SQLiteDatabase db = mOpenHelper.getReadableDatabase();		switch (uriMatcher.match(uri)) {		case PERSON_QUERY_ALL_CODE:  // 查询全部人的uri			if(db.isOpen()) {				Cursor cursor = db.query("person", projection, selection, selectionArgs, null, null, sortOrder);				return cursor;				// db.close(); 返回cursor结果集时, 不能够关闭数据库			}			break;		case PERSON_QUERY_ITEM_CODE:		// 查询的是单条数据, uri末尾出有一个id			if(db.isOpen()) {								long id = ContentUris.parseId(uri);								Cursor cursor = db.query("person", projection, "_id = ?", new String[]{id + ""}, null, null, sortOrder);				return cursor;			}			break;		default:			throw new IllegalArgumentException("uri不匹配: " + uri);		}		return null;	}	@Override	public String getType(Uri uri) {		switch (uriMatcher.match(uri)) {		case PERSON_QUERY_ALL_CODE: // 返回多条的MIME-type			return "vnd.android.cursor.dir/person";		case PERSON_QUERY_ITEM_CODE: // 返回单条的MIME-TYPE			return "vnd.android.cursor.item/person";		default:			break;		}		return null;	}	@Override	public Uri insert(Uri uri, ContentValues values) {				switch (uriMatcher.match(uri)) {		case PRESON_INSERT_CODE:	// 加入人到person表中			SQLiteDatabase db = mOpenHelper.getWritableDatabase();						if(db.isOpen()) {								long id = db.insert("person", null, values);								db.close();								return ContentUris.withAppendedId(uri, id);			}			break;		default:			throw new IllegalArgumentException("uri不匹配: " + uri);		}		return null;	}	@Override	public int delete(Uri uri, String selection, String[] selectionArgs) {		switch (uriMatcher.match(uri)) {		case PERSON_DELETE_CODE:	// 在person表中删除数据的操作			SQLiteDatabase db = mOpenHelper.getWritableDatabase();			if(db.isOpen()) {				int count = db.delete("person", selection, selectionArgs);				db.close();				return count;			}			break;		default:			throw new IllegalArgumentException("uri不匹配: " + uri);		}		return 0;	}	@Override	public int update(Uri uri, ContentValues values, String selection,			String[] selectionArgs) {		switch (uriMatcher.match(uri)) {		case PERSON_UPDATE_CODE: // 更新person表的操作			SQLiteDatabase db = mOpenHelper.getWritableDatabase();			if(db.isOpen()) {				int count = db.update("person", values, selection, selectionArgs);				db.close();				return count;			}			break;		default:			throw new IllegalArgumentException("uri不匹配: " + uri);		}		return 0;	}}

内容提供者訪问和权限

xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.itheima28.othercontentprovider" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="17" /> <instrumentation android:name="android.test.InstrumentationTestRunner" android:targetPackage="com.itheima28.othercontentprovider" > </instrumentation> <uses-permission android:name="aa.bb.cc.read"/> <uses-permission android:name="aa.bb.cc.write"/> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <uses-library android:name="android.test.runner" /> <activity android:name="com.itheima28.othercontentprovider.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>

package com.itheima28.othercontentprovider;import android.content.ContentResolver;import android.content.ContentUris;import android.content.ContentValues;import android.database.Cursor;import android.net.Uri;import android.test.AndroidTestCase;import android.util.Log;public class TextCase extends AndroidTestCase {	private static final String TAG = "TextCase";	public void testInsert() {		Uri uri = Uri.parse("content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/insert");				// 内容提供者訪问对象		ContentResolver resolver = getContext().getContentResolver();				ContentValues values = new ContentValues();		values.put("name", "fengjie");		values.put("age", 90);				uri = resolver.insert(uri, values);		Log.i(TAG, "uri: " + uri);		long id = ContentUris.parseId(uri);		Log.i(TAG, "加入到: " + id);	}		public void testDelete() {		Uri uri = Uri.parse("content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/delete");				// 内容提供者訪问对象		ContentResolver resolver = getContext().getContentResolver();				String where = "_id = ?

"; String[] selectionArgs = {"21"}; int count = resolver.delete(uri, where, selectionArgs); Log.i(TAG, "删除行: " + count); } public void testUpdate() { Uri uri = Uri.parse("content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/update"); // 内容提供者訪问对象 ContentResolver resolver = getContext().getContentResolver(); ContentValues values = new ContentValues(); values.put("name", "lisi"); int count = resolver.update(uri, values, "_id = ?", new String[]{"20"}); Log.i(TAG, "更新行: " + count); } public void testQueryAll() { Uri uri = Uri.parse("content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/queryAll"); // 内容提供者訪问对象 ContentResolver resolver = getContext().getContentResolver(); Cursor cursor = resolver.query(uri, new String[]{"_id", "name", "age"}, null, null, "_id desc"); if(cursor != null && cursor.getCount() > 0) { int id; String name; int age; while(cursor.moveToNext()) { id = cursor.getInt(0); name = cursor.getString(1); age = cursor.getInt(2); Log.i(TAG, "id: " + id + ", name: " + name + ", age: " + age); } cursor.close(); } } public void testQuerySingleItem() { Uri uri = Uri.parse("content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/query/#"); // 在uri的末尾加入一个id content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/query/20 uri = ContentUris.withAppendedId(uri, 20); // 内容提供者訪问对象 ContentResolver resolver = getContext().getContentResolver(); Cursor cursor = resolver.query(uri, new String[]{"_id", "name", "age"}, null, null, null); if(cursor != null && cursor.moveToFirst()) { int id = cursor.getInt(0); String name = cursor.getString(1); int age = cursor.getInt(2); cursor.close(); Log.i(TAG, "id: " + id + ", name: " + name + ", age: " + age); } } }

转载于:https://www.cnblogs.com/liguangsunls/p/7293877.html

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