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  • 17 一个ContentProvider的例子

    服务端(ContentProvider)

    • 目录结构图:
      这里写图片描述

    • MainActivity.java:

      package com.qf.day17_contentprovider_words_demo2;

import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;

import com.qf.day17_contentprovider_words_demo2.db.MyOpenHelper;

public class MainActivity extends Activity {

    private EditText etWord,etChina;
    private ListView lv;


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

        etWord  = (EditText) findViewById(R.id.et_word);
        etChina  = (EditText) findViewById(R.id.et_china);
        lv = (ListView) findViewById(R.id.lv);

        helper = new MyOpenHelper(MainActivity.this);

        getData();
    }

    //点击事件  提交按钮
    public void MyClick(View v){

        String strWord = etWord.getText().toString().trim();
        String strChina= etChina.getText().toString().trim();
        String sql = "insert into tb_words(word,detail)values(?,?)";
        helper.execData(sql, new String[]{strWord,strChina});

        getData();

    }

    public void getData(){

        String sql = "select * from tb_words";
        Cursor cursor = helper.queryData(sql, null);

        SimpleCursorAdapter adapter = new SimpleCursorAdapter(MainActivity.this,
                R.layout.item, cursor, 
                new String[]{"word","detail"}, 
                new int[]{R.id.tv_word,R.id.tv_china}, SimpleCursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);

        lv.setAdapter(adapter);
    }




}

    • MyOpenHelper.java(数据库类):

      package com.qf.day17_contentprovider_words_demo2.db;

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

public class MyOpenHelper extends SQLiteOpenHelper {

    private static final String NAME = "db_words.db";
    private static final int VERSION = 1;

    private SQLiteDatabase db;

    public MyOpenHelper(Context context, String name, CursorFactory factory,
            int version) {
        super(context, name, factory, version);
        // TODO Auto-generated constructor stub
    }
    public MyOpenHelper(Context context) {
        super(context, NAME, null, VERSION);
        // TODO Auto-generated constructor stub
        db = getReadableDatabase();
    }


    /**
     * 查询
     * @param sql
     * @param selectionArgs
     * @return
     */
    public Cursor queryData(String sql, String[] selectionArgs){

        Cursor cursor = db.rawQuery(sql, selectionArgs);
        return cursor;

    }

    /**
     * 增加  修改  删除
     * @param sql
     * @param bindArgs
     */
    public  boolean execData(String sql,Object[] bindArgs){
        try {
            if(bindArgs ==null){
                db.execSQL(sql);
            }else{
                db.execSQL(sql, bindArgs);
            }

            return true;

        } catch (Exception e) {
            // TODO: handle exception
        }
        return false;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        String sql ="create table if not exists tb_words(_id integer primary key autoincrement,word,detail)";
        //此表无作用只作为一个示范
        String sql1 ="create table if not exists tb_newwords(_id integer primary key autoincrement,word,detail)";
        db.execSQL(sql);
        db.execSQL(sql1);

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub

    }

}

    • MyContentProvider 

      package com.qf.day17_contentprovider_words_demo2;

import com.qf.day17_contentprovider_words_demo2.db.MyOpenHelper;

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 MyContentProvider extends ContentProvider{


    private MyOpenHelper helper;
    private SQLiteDatabase db;

    //com.qf.contentprovider_words.mycontentprovider 用于匹配意图的uri 
    private static UriMatcher uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);

    static{

        /**第一个参数 :意图 和清单文件中的authorities 相同
         * 第二个参数 :路径 
         * 第三个参数:对应uri对应编码
         *  通配符 : * 任意文本  #数字
         *  
         * 例子uriMatcher.addURI("aa.bb","cc/#",1)
         * 例子uriMatcher.addURI("aa.bb","cc/*",2)
         * 
         * 如果 在ContentResolver 的意图uri为  aa.bb.cc/3 那么跳转uriMatcher.addURI("aa.bb","cc/#",1)
         * 
         */
        //在内容解析器中只需要 填写 uri即可 例子 ： com.qf.contentprovider_words.mycontentprovider/words/123
        //content://com.qf.contentprovider_words.mycontentprovider/words/h
        uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "words", 1);
        uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "newwords", 2);
        uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "words/*", 3);//*匹配任意文本
        uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "words_id/#", 4);//*匹配任意数字
        uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "words_zh/*", 5);//*匹配任意中文

    }


    @Override
    public boolean onCreate() {
        // TODO Auto-generated method stub
        helper =  new MyOpenHelper(getContext());
        db  = helper.getReadableDatabase();
        return false;
    }



    @Override
    public String getType(Uri uri) {
        // TODO Auto-generated method stub
        return null;
    }


    @Override
    public Cursor query(Uri uri, String[] projection, String selection,
            String[] selectionArgs, String sortOrder) {
        // TODO Auto-generated method stub

        Cursor cursor =null;

        switch (uriMatcher.match(uri)) {
        case 1:
            //tb_words表中所有数据
            cursor = db.query("tb_words", projection, selection, selectionArgs, null, null, sortOrder);

            break;
        case 2:
            //tb_newwords表中所有数据
            cursor = db.query("tb_newwords", projection, selection, selectionArgs, null, null, sortOrder);

            break;
        case 3:
            //tb_words表中符合条件  word
            String data = uri.getLastPathSegment();//获取Uri最后的参数
            cursor = db.query("tb_words", projection, "word like ?", new String[]{data+"%"}, null, null, sortOrder);

            break;
        case 4:
            //tb_words表中符合条件 _id
            String data1 = uri.getLastPathSegment();//获取Uri最后的参数
            cursor = db.query("tb_words", projection, "_id = ?", new String[]{data1+""}, null, null, sortOrder);

            break;
        case 5:

            //tb_words表中符合条件 detail
            String data2 = uri.getLastPathSegment();//获取Uri最后的参数
            cursor = db.query("tb_words", projection, "detail like ?", new String[]{data2+"%"}, null, null, sortOrder);

            break;

        default:
            break;
        }

        return cursor;
    }

    @Override
    public Uri insert(Uri uri, ContentValues values) {
        // TODO Auto-generated method stub

        Uri resultUri = null;
        switch (uriMatcher.match(uri)) {
        case 1:

            long l = db.insert("tb_words", null, values);
            /**
             * 两种皆可返回正确id
             */
//          resultUri = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/words/"+l);
            resultUri = ContentUris.withAppendedId(uri, l);
            break;
        case 2:
            long l1 = db.insert("tb_newwords", null, values);
            /**
             * 两种皆可返回正确id
             */
//          resultUri = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/newwords/"+l1);
            resultUri = ContentUris.withAppendedId(uri, l1);
            break;

        default:
            break;
        }
        return resultUri;
    }




    @Override
    public int update(Uri uri, ContentValues values, String selection,
            String[] selectionArgs) {
        // TODO Auto-generated method stub
        int num =0;
        switch (uriMatcher.match(uri)) {
        case 1:
            num = db.update("tb_words", values, selection, selectionArgs);
            break;
        case 2:
            num = db.update("tb_newwords", values, selection, selectionArgs);
            break;

        default:
            break;
        }
        return num;
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        // TODO Auto-generated method stub
        int num =0;
        switch (uriMatcher.match(uri)) {
        case 1:
            num = db.delete("tb_words", selection, selectionArgs);
            break;
        case 2:
            num = db.delete("tb_newwords", selection, selectionArgs);
            break;

        default:
            break;
        }
        return num;
    }

}

    • layout布局文件：
      item

      <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView 
        android:id="@+id/tv_word"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#f00"
        android:textSize="20sp"
        android:text="hello"
        />
    <TextView 
        android:id="@+id/tv_china"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#00f"
        android:textSize="16sp"
        android:text="word"
        />


</LinearLayout>

      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=".MainActivity" >



    <EditText
        android:id="@+id/et_word"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入英文单词" />
    <EditText
        android:id="@+id/et_china"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入对应的意思" />

    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:text="提交"
        android:onClick="MyClick"
        />

    <TextView 
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#999900"
        android:text="以下显示单词列表"
        />

    <ListView 
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="#f00"
        android:dividerHeight="1dp"
        ></ListView>

</LinearLayout>

    客户端

    • 结构目录:
      这里写图片描述

    • MainActivity.java:

      package com.qf.day17_contentprovider_wordc_demo2;

import java.util.regex.Pattern;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;

public class MainActivity extends Activity {

    // //content://com.qf.contentprovider_words.mycontentprovider/words/
    // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
    // "words", 1);
    // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
    // "newwords", 2);
    // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
    // "words/*", 3);//*匹配任意文本
    // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
    // "words_id/#", 4);//*匹配任意数字
    // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
    // "words_zh/*", 5);//*匹配任意中文
    //

    private EditText etSearch;
    private ListView lv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        etSearch = (EditText) findViewById(R.id.et_search);
        lv = (ListView) findViewById(R.id.lv);
    }

    public void MyClick(View v) {
        // 根据输入文本进行查询
        String strdata = etSearch.getText().toString().trim();

        getData(strdata);

    }



    // 查询方法
    public void getData(String strdata) {

        ContentResolver resolver = getContentResolver();
        Uri uriWords = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/words");
        Uri uriWordsId = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/words_id");
        Uri uriWordsZh = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/words_zh");
        Cursor cursor = null;
        if (TextUtils.isEmpty(strdata)) {// 什么也没输入 直接查询所有
            cursor = resolver.query(uriWords, null, null, null, null);
        } else {
            if (isNumber(strdata)) {// 输入的数据 是否是数值
                // content://com.qf.contentprovider_words.mycontentprovider/words_id/45
                // 拼接id 123
                uriWordsId = ContentUris.withAppendedId(uriWordsId, Long.parseLong(strdata));
                cursor = resolver.query(uriWordsId, null, null, null, null);
            } else {
                if (isChina(strdata)) {// 是否是汉字
                    // 拼接中文 张
                    uriWordsZh = Uri.withAppendedPath(uriWordsZh, strdata);
                    cursor = resolver.query(uriWordsZh, null, null, null, null);
                } else {
                    // 拼接英文字符串 
                    uriWords = Uri.withAppendedPath(uriWords, strdata);
                    cursor = resolver.query(uriWords, null, null, null, null);
                }

            }
        }

        SimpleCursorAdapter adapter = new SimpleCursorAdapter(MainActivity.this, R.layout.item, cursor,
                new String[] { "word", "detail" }, new int[] { R.id.tv_word, R.id.tv_china },
                SimpleCursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);

        lv.setAdapter(adapter);

    }

    // 判断是否是数字
    public boolean isNumber(String data) {
        Pattern pattern = Pattern.compile("[0-9]+");
        return pattern.matcher(data).matches();

    }

    // 判断是否是中文
    public boolean isChina(String data) {
        Pattern pattern = Pattern.compile("[u4e00-u9fa5]+");
        return pattern.matcher(data).matches();

    }

}

    • layout布局:
      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=".MainActivity" >

    <EditText
        android:id="@+id/et_search"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入查询内容" />

    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="提交"
        android:onClick="MyClick"
        />

    <TextView 
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="以下展示查询内容"
        android:background="#999900"
        />
    <ListView 
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        ></ListView>

</LinearLayout>

      item.xml

      <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView 
        android:id="@+id/tv_word"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#f00"
        android:textSize="20sp"
        android:text="hello"
        />
    <TextView 
        android:id="@+id/tv_china"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#00f"
        android:textSize="16sp"
        android:text="word"
        />


</LinearLayout>
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  • 原文地址：https://www.cnblogs.com/muyuge/p/6152240.html
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