每天进步一点----- 内容提供者ContentProvider

package com.example.contactstest;

import java.util.ArrayList;
import java.util.List;

import android.os.Bundle;
import android.provider.ContactsContract;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.app.Activity;
import android.database.Cursor;

public class MainActivity extends Activity {

    ListView contactsView;

    ArrayAdapter<String> adapter;

    List<String> contactsList = new ArrayList<String>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        contactsView = (ListView) findViewById(R.id.contacts_view);
        adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, contactsList);
        contactsView.setAdapter(adapter);
        readContacts();
    }

    private void readContacts() {
        Cursor cursor = null;
        try {
            cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                    null, null, null, null);
            while (cursor.moveToNext()) {
                String displayName = cursor.getString(cursor
                        .getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
                String number = cursor.getString(cursor
                        .getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                contactsList.add(displayName + "\n" + number);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
    }

}

package com.example.databasetest;

import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;

public class DatabaseProvider extends ContentProvider {

    public static final int BOOK_DIR = 0;

    public static final int BOOK_ITEM = 1;

    public static final int CATEGORY_DIR = 2;

    public static final int CATEGORY_ITEM = 3;

    public static final String AUTHORITY = "com.example.databasetest.provider";

    private static UriMatcher uriMatcher;

    private MyDatabaseHelper dbHelper;

    static {
        uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
        uriMatcher.addURI(AUTHORITY, "book", BOOK_DIR);
        uriMatcher.addURI(AUTHORITY, "book/#", BOOK_ITEM);
        uriMatcher.addURI(AUTHORITY, "category", CATEGORY_DIR);
        uriMatcher.addURI(AUTHORITY, "category/#", CATEGORY_ITEM);
    }

    @Override
    public boolean onCreate() {
        dbHelper = new MyDatabaseHelper(getContext(), "BookStore.db", null, 2);
        return true;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
            String sortOrder) {
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        Cursor cursor = null;
        switch (uriMatcher.match(uri)) {
        case BOOK_DIR:
            cursor = db.query("Book", projection, selection, selectionArgs, null, null, sortOrder);
            break;
        case BOOK_ITEM:
            String bookId = uri.getPathSegments().get(1);
            cursor = db.query("Book", projection, "id = ?", new String[] { bookId }, null, null,
                    sortOrder);
            break;
        case CATEGORY_DIR:
            cursor = db.query("Category", projection, selection, selectionArgs, null, null,
                    sortOrder);
            break;
        case CATEGORY_ITEM:
            String categoryId = uri.getPathSegments().get(1);
            cursor = db.query("Category", projection, "id = ?", new String[] { categoryId }, null,
                    null, sortOrder);
            break;
        default:
            break;
        }
        return cursor;
    }

    @Override
    public Uri insert(Uri uri, ContentValues values) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        Uri uriReturn = null;
        switch (uriMatcher.match(uri)) {
        case BOOK_DIR:
        case BOOK_ITEM:
            long newBookId = db.insert("Book", null, values);
            uriReturn = Uri.parse("content://" + AUTHORITY + "/book/" + newBookId);
            break;
        case CATEGORY_DIR:
        case CATEGORY_ITEM:
            long newCategoryId = db.insert("Category", null, values);
            uriReturn = Uri.parse("content://" + AUTHORITY + "/category/" + newCategoryId);
            break;
        default:
            break;
        }
        return uriReturn;
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        int updatedRows = 0;
        switch (uriMatcher.match(uri)) {
        case BOOK_DIR:
            updatedRows = db.update("Book", values, selection, selectionArgs);
            break;
        case BOOK_ITEM:
            String bookId = uri.getPathSegments().get(1);
            updatedRows = db.update("Book", values, "id = ?", new String[] { bookId });
            break;
        case CATEGORY_DIR:
            updatedRows = db.update("Category", values, selection, selectionArgs);
            break;
        case CATEGORY_ITEM:
            String categoryId = uri.getPathSegments().get(1);
            updatedRows = db.update("Category", values, "id = ?", new String[] { categoryId });
            break;
        default:
            break;
        }
        return updatedRows;
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        int deletedRows = 0;
        switch (uriMatcher.match(uri)) {
        case BOOK_DIR:
            deletedRows = db.delete("Book", selection, selectionArgs);
            break;
        case BOOK_ITEM:
            String bookId = uri.getPathSegments().get(1);
            deletedRows = db.delete("Book", "id = ?", new String[] { bookId });
            break;
        case CATEGORY_DIR:
            deletedRows = db.delete("Category", selection, selectionArgs);
            break;
        case CATEGORY_ITEM:
            String categoryId = uri.getPathSegments().get(1);
            deletedRows = db.delete("Category", "id = ?", new String[] { categoryId });
            break;
        default:
            break;
        }
        return deletedRows;
    }

    @Override
    public String getType(Uri uri) {
        switch (uriMatcher.match(uri)) {
        case BOOK_DIR:
            return "vnd.android.cursor.dir/vnd.com.example.databasetest.provider.book";
        case BOOK_ITEM:
            return "vnd.android.cursor.item/vnd.com.example.databasetest.provider.book";
        case CATEGORY_DIR:
            return "vnd.android.cursor.dir/vnd.com.example.databasetest.provider.category";
        case CATEGORY_ITEM:
            return "vnd.android.cursor.item/vnd.com.example.databasetest.provider.category";
        }
        return null;
    }

}

package com.example.databasetest;

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

public class MyDatabaseHelper extends SQLiteOpenHelper {

    public static final String CREATE_BOOK = "create table Book ("
            + "id integer primary key autoincrement, " 
            + "author text, "
            + "price real, " 
            + "pages integer, " 
            + "name text)";
    
    public static final String CREATE_CATEGORY = "create table Category ("
            + "id integer primary key autoincrement, "
            + "category_name text, "
            + "category_code integer)";

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_BOOK);
        db.execSQL(CREATE_CATEGORY);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("drop table if exists Book");
        db.execSQL("drop table if exists Category");
        onCreate(db);
    }

}

package com.example.providertest;

import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    
    private String newId;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button addData = (Button) findViewById(R.id.add_data);
        addData.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Uri uri = Uri
                        .parse("content://com.example.databasetest.provider/book");
                ContentValues values = new ContentValues();
                values.put("name", "A Clash of Kings");
                values.put("author", "George Martin");
                values.put("pages", 1040);
                values.put("price", 55.55);
                Uri newUri = getContentResolver().insert(uri, values);
                newId = newUri.getPathSegments().get(1);
            }
        });
        Button queryData = (Button) findViewById(R.id.query_data);
        queryData.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Uri uri = Uri
                        .parse("content://com.example.databasetest.provider/book");
                Cursor cursor = getContentResolver().query(uri, null, null,
                        null, null);
                if (cursor != null) {
                    while (cursor.moveToNext()) {
                        String name = cursor.getString(cursor
                                .getColumnIndex("name"));
                        String author = cursor.getString(cursor
                                .getColumnIndex("author"));
                        int pages = cursor.getInt(cursor
                                .getColumnIndex("pages"));
                        double price = cursor.getDouble(cursor
                                .getColumnIndex("price"));
                        Log.d("MainActivity", "book name is " + name);
                        Log.d("MainActivity", "book author is " + author);
                        Log.d("MainActivity", "book pages is " + pages);
                        Log.d("MainActivity", "book price is " + price);
                    }
                    cursor.close();
                }
            }
        });
        Button updateData = (Button) findViewById(R.id.update_data);
        updateData.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Uri uri = Uri
                        .parse("content://com.example.databasetest.provider/book/" + newId);
                ContentValues values = new ContentValues();
                values.put("name", "A Storm of Swords");
                values.put("pages", 1216);
                values.put("price", 24.05);
                getContentResolver().update(uri, values, null, null);
            }
        });
        Button deleteData = (Button) findViewById(R.id.delete_data);
        deleteData.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Uri uri = Uri
                        .parse("content://com.example.databasetest.provider/book/" + newId);
                getContentResolver().delete(uri, null, null);
            }
        }); 
    }

}