ContentResovler取得音乐通讯录等系统相关数据

一、多媒体数据库与ContentResovler：

Android提供的多媒体数据库MediaStore保存了音频、视频、图片的全部基本信息，
保存在/data/data/com.android.providers.media/databases下的external.db数据库
事实上以下URI是ContentProvider给我们封装了用来访问系统数据库的入口

二、ContentResobler相关类比

1. ContentProvider相当于服务器，将系统的数据库访问接口URI给我们；

• ContentResolver相当于浏览器，输入URI和相应的条件，就可以访问数据；
• 每个URI都对应着一个相关数据表，使用ContentResolver相关方法进行表查询；

4. ContentResolver更像是SQLiteDatebase类,有查询，删除等相关方法；

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三、一些常用的URI(表)：

• 音乐URI(表)
  MediaStore.Audio.Media.EXTERNAL_CONTENT_URI=content://media/external/audio/media
• 专辑URI(表)
  MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI=//content://media/external/audio/albums
• 图片URI(表)
  MediaStore.Images.Media.EXTERNAL_CONTENT_URI=content://media/external/images/media
• 视频URI(表)
  MediaStore.Video.Media.EXTERNAL_CONTENT_URI=content://media/external/video/media
  除了媒体库，访问通讯录时，使用通讯录数据库
• 通讯录URI(表)
  ContactsContract.Contacts.CONTENT_URI=content://com.android.contacts/contacts
• 电话URI(表) 取得电话号
  ContactsContract.CommonDataKinds.Phone.CONTENT_URI=content://com.android.contacts/data/phones

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在Activity中获取ContentResolver对象，并在AndroidManifest.xml加上访问外部数据库权限

ContentResolver resolver=getContentResolver()

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

四、对URI操作，取数据

以下java代码都在Activity中书写，含有View对象参数的为Button的Click点击事件

(一)、访问sd卡的图片

获取图片相关信息,使用存放图片的URI(表)存放

 public void getImage(View view){
        ContentResolver resolver=getContentResolver();
        Uri imageUri=MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
        String imageName=MediaStore.Images.Media.DISPLAY_NAME;
        String path=MediaStore.Images.Media.DATA;
        String dirName= MediaStore.Images.Media.BUCKET_DISPLAY_NAME;//存储文件夹的名字
        String id=MediaStore.Images.Media._ID;
        Cursor cursor=resolver.query(imageUri,new String[]{imageName,path,dirName,id},null,null,null,null);
        while(cursor.moveToNext()){
            Log.i("dayang","imageName:"+cursor.getString(cursor.getColumnIndex(imageName)));
            Log.i("dayang","path:"+cursor.getString(cursor.getColumnIndex(path)));
            Log.i("dayang","dirName:"+cursor.getString(cursor.getColumnIndex(dirName)));
            String image_id=cursor.getString(cursor.getColumnIndex(id));
            Log.i("dayang","id:"+image_id);
            Log.i("dayang","缩略图存放路径path:"+getThumbnail(image_id));
        }
    }

获取图片缩略图相关信息，使用图片缩略图的URI(表)

private String getThumbnail(String id){
        ContentResolver resolver=getContentResolver();
        Uri imageUri=MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI;
        String path=MediaStore.Images.Thumbnails.DATA;
        String image_id=MediaStore.Images.Thumbnails.IMAGE_ID;
        Cursor cursor=resolver.query(imageUri,new String[]{path},image_id+"=?",new String[]{id},null);
        String str;
        while(cursor.moveToNext()){
            str=cursor.getString(cursor.getColumnIndex(path));
            return str;
        }
        return null;
    }

(二)、访问sd卡的音频

获取音乐的相关信息，使用音乐URI(表)

public  void getMusic(View view){
        ContentResolver resolver=getContentResolver();
        Uri musicUri=MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        String musicName=MediaStore.Audio.Media.TITLE;
        String musicFileName=MediaStore.Audio.Media.DISPLAY_NAME;
        String artist=MediaStore.Audio.Media.ARTIST;
        String album=MediaStore.Audio.Media.ALBUM;
        String path=MediaStore.Audio.Media.DATA;
        String album_id=MediaStore.Audio.Media.ALBUM_ID;
        Cursor cursor=resolver.query(musicUri,new String[]{musicFileName,musicName,artist,album,path,album_id},null,null,null,null);
        while(cursor.moveToNext()){
            Log.i("dayang","带文件后缀，musicFileName:"+cursor.getString(cursor.getColumnIndex(musicFileName)));
            Log.i("dayang","musicName:"+cursor.getString(cursor.getColumnIndex(musicName)));
            Log.i("dayang","artist:"+cursor.getString(cursor.getColumnIndex(album)));
            Log.i("dayang","path:"+cursor.getString(cursor.getColumnIndex(path)));
            Log.i("dayang","album:"+cursor.getString(cursor.getColumnIndex(album)));
            String id=cursor.getString(cursor.getColumnIndex(album_id));
            Log.i("dayang","album_id"+id);
            Log.i("dayang","album_thumbnial"+getAlbumThumbnail(id));//获取缩略图
        }
    }

获取专辑缩略图，使用专辑URI(表)

     /**
     * 得到专辑缩略图
     * @return
     */
    public String getAlbumThumbnail(String album_id){
        ContentResolver resolver=getContentResolver();
        Uri albumUri=MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI;
        String thumbnail=MediaStore.Audio.Albums.ALBUM_ART;
        String id=MediaStore.Audio.Albums._ID;
        String str=null;
        Cursor cursor=resolver.query(albumUri,new String[]{thumbnail},id+"=?",new String[]{album_id},null);
        while(cursor.moveToNext()){
            str=cursor.getString(cursor.getColumnIndex(thumbnail));
        }
        return str;
    }

(三)、访问sd卡的视频，使用视频URI(表)

public void getVideo(View view){
        ContentResolver resolver=getContentResolver();
        Uri videoUri=MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
        String videoName=MediaStore.Video.Media.DISPLAY_NAME;
        String videoArtist=MediaStore.Video.Media.ARTIST;
        String path=MediaStore.Video.Media.DATA;
        String parentFile=MediaStore.Video.Media.BUCKET_DISPLAY_NAME;
        Cursor cursor=resolver.query(videoUri,new String[]{videoName,videoArtist,path,parentFile},null,null,null);
        while(cursor.moveToNext()){
            Log.i("dayang","videoName"+cursor.getString(cursor.getColumnIndex(videoName)));
            Log.i("dayang","path"+cursor.getString(cursor.getColumnIndex(videoArtist)));
            Log.i("dayang","parentFile"+cursor.getString(cursor.getColumnIndex(parentFile)));
            Log.i("dayang","videoArtist"+cursor.getString(cursor.getColumnIndex(videoArtist)));
        }
    }

(四)、获取通讯录，使用通讯录URI(表)

访问通讯录数据库，在AndroidManifest.xml加上访问通讯录权限

<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_CONTACTS"/>

获取通讯录中联系人名字，相应id

public void getContact(View view){
        ContentResolver resolver=getContentResolver();
        Uri contactUri= ContactsContract.Contacts.CONTENT_URI;
        String name=ContactsContract.Contacts.DISPLAY_NAME;
        String id=ContactsContract.Contacts._ID;
        Cursor cursor=resolver.query(contactUri,new String[]{name,id},null,null,null,null);
        while(cursor.moveToNext()){
            Log.i("dayang","name:"+cursor.getString(cursor.getColumnIndex(name)));
            String contact_id=cursor.getString(cursor.getColumnIndex(id));
            Log.i("dayang","id:"+contact_id);
            Log.i("dayang","number:"+getNumber(contact_id));//调用getNumber方法
        }
    }

获取通讯录中联系人电话号

public String getNumber(String id){
        ContentResolver resolver=getContentResolver();
        Uri numberUri=ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
        Log.i("dayang",numberUri+"");
        String number=ContactsContract.CommonDataKinds.Phone.NUMBER;
        String nickname=ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME;
        String contact_id=ContactsContract.CommonDataKinds.Phone.CONTACT_ID;
        Cursor cursor=resolver.query(numberUri,new String[]{number,nickname},contact_id+"=?",new String[]{id},null);
        String str=null;
        while(cursor.moveToNext()){
            str=cursor.getString(cursor.getColumnIndex(number));
            Log.i("dayang","nickname"+cursor.getString(cursor.getColumnIndex(nickname)));
            return str;
        }
        return str;
    }