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ContentProvider，是自身APP開(kāi)放給第三方APP的，用于訪問(wèn)自身數(shù)據(jù)庫(kù)數(shù)據(jù)的接口。
第三方APP可以通過(guò)該接口，對(duì)指定的數(shù)據(jù)進(jìn)行增刪改查。
那么如何定義自身的ContentProvider接口呢？
在回答問(wèn)題之前，先來(lái)關(guān)注一下Uri。
原因在于，uri是ContentProvider解析外部請(qǐng)求（或者說(shuō)是，第三方訪問(wèn)自身數(shù)據(jù)庫(kù)）的關(guān)鍵參數(shù)。
Uri的字符串格式如下
content://package/table/id
例如
content://com.breakloop.sqlitehelperdemo/hero/1
從上方Uri示例中，可以獲取到以下信息。
第三方APP想要
訪問(wèn)com.breakloop.sqlitehelperdemo的數(shù)據(jù)庫(kù)。至于哪個(gè)，由contentProvider內(nèi)部映射指定。
訪問(wèn)表hero。至于表名是不是真為hero，也由contentProvider說(shuō)了算。
訪問(wèn)id為1的數(shù)據(jù)。至于是不是id代表的具體含義，解釋權(quán)也歸contentProvider。
那么，第三方APP將Uri傳入后，ContentProvider如何將其map為具體的數(shù)據(jù)庫(kù)操作呢？
這便有了UriMatcher工具類(lèi)的引入。
該工具類(lèi)，可以將Uri映射為int類(lèi)型的行為代碼。行為代碼，可以看做是ContentProvider自定義的枚舉類(lèi)型。而不同的行為代碼，綁定不同的數(shù)據(jù)庫(kù)操作。
我們先來(lái)看一下，Uri與行為代碼的映射關(guān)系
????public?final?static?String?AUTHORITY="com.breakloop.contentproviderdemo1";????public?final?static?int?BY_NAME=1;????public?final?static?int?BY_AGE=2;????public?final?static?int?BY_SEX=3;????public?final?static?int?BY_NONE=0;????public?final?static?String?PATH_BY_NAME=DBConst.TABLE_PERSON+"/ByName/*";????public?final?static?String?PATH_BY_AGE=DBConst.TABLE_PERSON+"/ByAge/#";????public?final?static?String?PATH_BY_SEX=DBConst.TABLE_PERSON+"/BySex/*"; }
static?{
????matcher=new?UriMatcher(UriMatcher.NO_MATCH);
????matcher.addURI(MatcherConst.AUTHORITY,MatcherConst.PATH_BY_NAME,MatcherConst.BY_NAME);
????matcher.addURI(MatcherConst.AUTHORITY,MatcherConst.PATH_BY_AGE,MatcherConst.BY_AGE);
????matcher.addURI(MatcherConst.AUTHORITY,MatcherConst.PATH_BY_SEX,MatcherConst.BY_SEX);
????matcher.addURI(MatcherConst.AUTHORITY,DBConst.TABLE_PERSON,MatcherConst.BY_NONE);
}在上面的示例中，UriMatch綁定了四個(gè)Uri，并將各個(gè)Uri映射為四個(gè)行為代碼。
其中，用到了轉(zhuǎn)義符。#代表任意數(shù)字，*代表任意字母。
那么如何將行為代碼映射為具體的數(shù)據(jù)庫(kù)操作呢？，換句話(huà)說(shuō)，在哪兒使用UriMatcher呢？當(dāng)然是ContentProvider中?。?！在ContentProvider中的增刪改查方法中，完成操作映射。
我們來(lái)看一下，ContentProvider的創(chuàng)建。
先用Android Studio 創(chuàng)建一個(gè)ContentProvider.
創(chuàng)建過(guò)程中，需要提供AUTHORITY,
ContentProvider生成后，Android Studio將自動(dòng)幫助ContentProvider在Manifest中進(jìn)行注冊(cè)。
接下來(lái)，我們看看ContentProvider的結(jié)構(gòu)。
import?android.content.ContentProvider;import?android.content.ContentValues;import?android.content.UriMatcher;import?android.database.Cursor;import?android.net.Uri;public?class?MyContentProvider?extends?ContentProvider?{????public?MyContentProvider()?{
????}????@Override
????public?int?delete(Uri?uri,?String?selection,?String[]?selectionArgs)?{????????//?Implement?this?to?handle?requests?to?delete?one?or?more?rows.
????????throw?new?UnsupportedOperationException("Not?yet?implemented");
????}????@Override
????public?String?getType(Uri?uri)?{????????//?TODO:?Implement?this?to?handle?requests?for?the?MIME?type?of?the?data
????????//?at?the?given?URI.
????????throw?new?UnsupportedOperationException("Not?yet?implemented");
????}????@Override
????public?Uri?insert(Uri?uri,?ContentValues?values)?{????????//?TODO:?Implement?this?to?handle?requests?to?insert?a?new?row.
????????throw?new?UnsupportedOperationException("Not?yet?implemented");
????}????@Override
????public?boolean?onCreate()?{????????//?TODO:?Implement?this?to?initialize?your?content?provider?on?startup.
????????return?false;
????}????@Override
????public?Cursor?query(Uri?uri,?String[]?projection,?String?selection,
????????????????????????String[]?selectionArgs,?String?sortOrder)?{????????//?TODO:?Implement?this?to?handle?query?requests?from?clients.
????????throw?new?UnsupportedOperationException("Not?yet?implemented");
????}????@Override
????public?int?update(Uri?uri,?ContentValues?values,?String?selection,
??????????????????????String[]?selectionArgs)?{????????//?TODO:?Implement?this?to?handle?requests?to?update?one?or?more?rows.
????????throw?new?UnsupportedOperationException("Not?yet?implemented");
????}
}一共七個(gè)方法。包括一個(gè)構(gòu)造方法，四個(gè)數(shù)據(jù)庫(kù)方法（增刪改查），一個(gè)初始化方法（onCreate）,還有一個(gè)getType。
關(guān)于getType，我們之后解釋。
關(guān)于構(gòu)造方法，沒(méi)什么可解釋的。
關(guān)于初始化方法，當(dāng)返回true時(shí)，表明初始化成功，否則，失敗。由于我們要對(duì)數(shù)據(jù)庫(kù)進(jìn)行操作，因此，需要獲取sqlite數(shù)據(jù)庫(kù)對(duì)象。
public?boolean?onCreate()?{
????helper=new?mySqliteHelper(getContext(),DBConst.DB_NAME,null,1);????return?true;
}關(guān)于數(shù)據(jù)庫(kù)方法，我們看到傳參中存在Uri，因此，這里需要用到UirMatcher了。我們將剛才的UriMatcher代碼段，加入MyContentProvider.這樣，我們就可以在各個(gè)數(shù)據(jù)庫(kù)方法中，解析Uri了。同時(shí)，由于sqlite數(shù)據(jù)庫(kù)對(duì)象的存在，進(jìn)而可以對(duì)數(shù)據(jù)庫(kù)進(jìn)行相應(yīng)操作。
我們先看一下最簡(jiǎn)單的插入操作。
????public?Uri?insert(Uri?uri,?ContentValues?values)?{
????????Uri?returnUri=null;
????????SQLiteDatabase?db=helper.getWritableDatabase();????????switch?(matcher.match(uri)){????????????case?MatcherConst.BY_NONE:????????????????long?recordID=db.insert(DBConst.TABLE_PERSON,null,values);
????????????????returnUri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/"+recordID);????????????????break;????????????default:????????????????break;
????????}????????return?returnUri;
????}再來(lái)看一下稍微復(fù)雜的查詢(xún)。
????public?Cursor?query(Uri?uri,?String[]?projection,?String?selection,????????????????????????String[]?selectionArgs,?String?sortOrder)?{
????????Cursor?cursor=null;
????????SQLiteDatabase?db=helper.getReadableDatabase();????????switch?(matcher.match(uri)){????????????case?MatcherConst.BY_NONE:
????????????????cursor=db.query(DBConst.TABLE_PERSON,projection,selection,selectionArgs,null,null,sortOrder);????????????????break;????????????case?MatcherConst.BY_AGE:
????????????????cursor=db.query(DBConst.TABLE_PERSON,projection,DBConst.COLUMN_AGE+"=?",new?String[]{uri.getPathSegments().get(2)},null,null,sortOrder);????????????????break;????????????case?MatcherConst.BY_SEX:
????????????????cursor=db.query(DBConst.TABLE_PERSON,projection,DBConst.COLUMN_SEX+"=?",new?String[]{uri.getPathSegments().get(2)},null,null,sortOrder);????????????????break;????????????case?MatcherConst.BY_NAME:
????????????????cursor=db.query(DBConst.TABLE_PERSON,projection,DBConst.COLUMN_NAME+"=?",new?String[]{uri.getPathSegments().get(2)},null,null,sortOrder);????????????????break;????????????default:????????????????break;
????????}????????return?cursor;
????}這里需要注意的是，如何取Uri中的傳入數(shù)據(jù)。使用的獲取方法是uri.getPathSegments().get(index)。該方法獲取的是AUTHORITY后面的String部分。
然后，以”/”為分隔符，生成String[]。
接著是更新操作。
?@Override
????public?int?update(Uri?uri,?ContentValues?values,?String?selection,
??????????????????????String[]?selectionArgs)?{????????int?recordID=0;
????????SQLiteDatabase?db=helper.getWritableDatabase();????????switch?(matcher.match(uri)){????????????case?MatcherConst.BY_NONE:
????????????????recordID=db.update(DBConst.TABLE_PERSON,values,null,null);????????????????break;????????????case?MatcherConst.BY_AGE:
????????????????recordID=db.update(DBConst.TABLE_PERSON,values,DBConst.COLUMN_AGE+"=?",new?String[]{uri.getPathSegments().get(2)});????????????????break;????????????case?MatcherConst.BY_SEX:
????????????????recordID=db.update(DBConst.TABLE_PERSON,values,DBConst.COLUMN_SEX+"=?",new?String[]{uri.getPathSegments().get(2)});????????????????break;????????????case?MatcherConst.BY_NAME:
????????????????recordID=db.update(DBConst.TABLE_PERSON,values,DBConst.COLUMN_NAME+"=?",new?String[]{uri.getPathSegments().get(2)});????????????????break;????????????default:????????????????break;
????????}????????return?recordID;
????}還有刪除。
????public?int?delete(Uri?uri,?String?selection,?String[]?selectionArgs)?{????????int?recordID=0;
????????SQLiteDatabase?db=helper.getWritableDatabase();????????switch?(matcher.match(uri)){????????????case?MatcherConst.BY_NONE:
????????????????recordID=db.delete(DBConst.TABLE_PERSON,null,null);????????????????break;????????????case?MatcherConst.BY_AGE:
????????????????recordID=db.delete(DBConst.TABLE_PERSON,DBConst.COLUMN_AGE+"=?",new?String[]{uri.getPathSegments().get(2)});????????????????break;????????????case?MatcherConst.BY_SEX:
????????????????recordID=db.delete(DBConst.TABLE_PERSON,DBConst.COLUMN_SEX+"=?",new?String[]{uri.getPathSegments().get(2)});????????????????break;????????????case?MatcherConst.BY_NAME:
????????????????recordID=db.delete(DBConst.TABLE_PERSON,DBConst.COLUMN_NAME+"=?",new?String[]{uri.getPathSegments().get(2)});????????????????break;????????????default:????????????????break;
????????}????????return?recordID;
????}那么，第三方如何調(diào)用ContentProvider呢？
這里，我們新建一個(gè)工程contentproviderdemo2，在必要的位置使用方法
public ContentResolver getContentResolver()
獲取ContentProvider實(shí)例，之后便可傳入U(xiǎn)ri，調(diào)用數(shù)據(jù)庫(kù)相關(guān)方法了。
例如，我們插入四條記錄。
????????Uri?returnUri=null;
????????ContentResolver?resolver=getContentResolver();
????????Uri?uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);
????????ContentValues?values=new?ContentValues();
????????values.put(DBConst.COLUMN_NAME,"A");
????????values.put(DBConst.COLUMN_AGE,10);
????????values.put(DBConst.COLUMN_SEX,"Male");
????????returnUri=resolver.insert(uri,values);????????if(returnUri!=null)
????????Log.i(TAG,?"return?Uri?=?"+returnUri.toString());
????????values.put(DBConst.COLUMN_NAME,"B");
????????values.put(DBConst.COLUMN_AGE,11);
????????values.put(DBConst.COLUMN_SEX,"Male");
????????returnUri=resolver.insert(uri,values);????????if(returnUri!=null)
????????Log.i(TAG,?"return?Uri?=?"+returnUri.toString());
????????values.put(DBConst.COLUMN_NAME,"C");
????????values.put(DBConst.COLUMN_AGE,12);
????????values.put(DBConst.COLUMN_SEX,"Female");
????????returnUri=resolver.insert(uri,values);????????if(returnUri!=null)
????????Log.i(TAG,?"return?Uri?=?"+returnUri.toString());
????????values.put(DBConst.COLUMN_NAME,"D");
????????values.put(DBConst.COLUMN_AGE,13);
????????values.put(DBConst.COLUMN_SEX,"Female");
????????returnUri=resolver.insert(uri,values);????????if(returnUri!=null)
????????Log.i(TAG,?"return?Uri?=?"+returnUri.toString());我們看一下輸出結(jié)果。
I/com.breakloop.contentproviderdemo2.MainActivity:?return?Uri?=?content://com.breakloop.contentproviderdemo1/PERSON/1I/com.breakloop.contentproviderdemo2.MainActivity:?return?Uri?=?content://com.breakloop.contentproviderdemo1/PERSON/2I/com.breakloop.contentproviderdemo2.MainActivity:?return?Uri?=?content://com.breakloop.contentproviderdemo1/PERSON/3I/com.breakloop.contentproviderdemo2.MainActivity:?return?Uri?=?content://com.breakloop.contentproviderdemo1/PERSON/4
既然，寫(xiě)入成功，那我們查詢(xún)一下。
????public?void?selectRecord(){
????????Uri?uri;
????????String?name="A";????????int?age=11;
????????String?sex="Male";
????????Log.i(TAG,?"Select?by?Name");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/ByName/"+name);
????????selectRecord(uri);
????????Log.i(TAG,?"Select?by?Age");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/ByAge/"+age);
????????selectRecord(uri);
????????Log.i(TAG,?"Select?by?Sex");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/BySex/"+sex);
????????selectRecord(uri);
????????Log.i(TAG,?"Select?All");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);
????????selectRecord(uri);
????}????private?void?selectRecord(Uri?uri){
????????Cursor?cursor;
????????cursor=resolver.query(uri,new?String[]{DBConst.COLUMN_AGE,?DBConst.COLUMN_NAME,?DBConst.COLUMN_SEX},null,null,null);????????if(cursor!=null){????????????while(cursor.moveToNext()){
????????????????Log.i(TAG,?"name?=?"+cursor.getString(1)+?"?age?=?"+cursor.getInt(0)?+"?"+cursor.getString(2));
????????????}
????????}
????}輸出結(jié)果如下
I/com.breakloop.contentproviderdemo2.MainActivity:?Select?by?Name I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?A?age?=?10?Male I/com.breakloop.contentproviderdemo2.MainActivity:?Select?by?Age I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?B?age?=?11?Male I/com.breakloop.contentproviderdemo2.MainActivity:?Select?by?Sex I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?A?age?=?10?Male I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?B?age?=?11?Male I/com.breakloop.contentproviderdemo2.MainActivity:?Select?All I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?A?age?=?10?Male I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?B?age?=?11?Male I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?C?age?=?12?Female I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?D?age?=?13?Female
我們?cè)賮?lái)更新一下。
????public?void?updateRecord(){
????????Uri?uri;
????????String?name="A";????????int?age=11;
????????String?sex="Female";
????????ContentValues?values=new?ContentValues();
????????Log.i(TAG,?"Update?by?Name");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/ByName/"+name);
????????values.put(DBConst.COLUMN_NAME,name+name);
????????update(uri,values);
????????Log.i(TAG,?"Update?by?Age");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/ByAge/"+age);
????????values.clear();
????????values.put(DBConst.COLUMN_AGE,14);
????????update(uri,values);
????????Log.i(TAG,?"Update?by?Sex");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/BySex/"+sex);
????????values.clear();
????????values.put(DBConst.COLUMN_AGE,15);
????????update(uri,values);
????????Log.i(TAG,?"Update?All");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);
????????values.put(DBConst.COLUMN_SEX,"Male");
????????update(uri,values);
????????Log.i(TAG,?"Select?All");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);
????????selectRecord(uri);
????}????private?void?update(Uri?uri,ContentValues?values){????????int?count;
????????count=resolver.update(uri,values,null,null);
????????Log.i(TAG,?"update?"+count+"?record");
????}結(jié)果如下
I/com.breakloop.contentproviderdemo2.MainActivity:?Update?by?Name I/com.breakloop.contentproviderdemo2.MainActivity:?update?1?record I/com.breakloop.contentproviderdemo2.MainActivity:?Update?by?Age I/com.breakloop.contentproviderdemo2.MainActivity:?update?1?record I/com.breakloop.contentproviderdemo2.MainActivity:?Update?by?Sex I/com.breakloop.contentproviderdemo2.MainActivity:?update?2?record I/com.breakloop.contentproviderdemo2.MainActivity:?Update?All I/com.breakloop.contentproviderdemo2.MainActivity:?update?4?record I/com.breakloop.contentproviderdemo2.MainActivity:?Select?All I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?AA?age?=?15?Male I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?B?age?=?15?Male I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?C?age?=?15?Male I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?D?age?=?15?Male
都不要了，刪除?。ㄟ@里是對(duì)更新前的數(shù)據(jù)庫(kù)進(jìn)行的操作）
????public?void?deleteRecord(){
????????Uri?uri;
????????String?name="A";????????int?age=11;
????????String?sex="Female";
????????Log.i(TAG,?"Delete?by?Name");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/ByName/"+name);????????delete(uri);
????????Log.i(TAG,?"Select?All");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);
????????selectRecord(uri);
????????Log.i(TAG,?"Delete?by?Age");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/ByAge/"+age);????????delete(uri);
????????Log.i(TAG,?"Select?All");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);
????????selectRecord(uri);
????????Log.i(TAG,?"Delete?by?Sex");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON+"/BySex/"+sex);????????delete(uri);
????????Log.i(TAG,?"Select?All");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);
????????selectRecord(uri);
????????Log.i(TAG,?"Delete?All");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);????????delete(uri);
????????Log.i(TAG,?"Select?All");
????????uri=Uri.parse("content://"+MatcherConst.AUTHORITY+"/"+DBConst.TABLE_PERSON);
????????selectRecord(uri);
????}????private?void?delete(Uri?uri){????????int?count;
????????count=resolver.delete(uri,null,null);
????????Log.i(TAG,?"delete?"+count+"?record");
????}結(jié)果如下
I/com.breakloop.contentproviderdemo2.MainActivity:?delete?1?record I/com.breakloop.contentproviderdemo2.MainActivity:?Select?All I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?B?age?=?11?Male I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?C?age?=?12?Female I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?D?age?=?13?Female I/com.breakloop.contentproviderdemo2.MainActivity:?Delete?by?Age I/com.breakloop.contentproviderdemo2.MainActivity:?delete?1?record I/com.breakloop.contentproviderdemo2.MainActivity:?Select?All I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?C?age?=?12?Female I/com.breakloop.contentproviderdemo2.MainActivity:?name?=?D?age?=?13?Female I/com.breakloop.contentproviderdemo2.MainActivity:?Delete?by?Sex I/com.breakloop.contentproviderdemo2.MainActivity:?delete?2?record I/com.breakloop.contentproviderdemo2.MainActivity:?Select?All I/com.breakloop.contentproviderdemo2.MainActivity:?Delete?All I/com.breakloop.contentproviderdemo2.MainActivity:?delete?0?record I/com.breakloop.contentproviderdemo2.MainActivity:?Select?All
至此，ContentProvider的創(chuàng)建和使用便介紹完了。
如果，只是為了使用，可以只看到這里就好了！
之后的部分，本文還未找到答案！因此，只是記錄！
如果有知道的朋友，還望指點(diǎn)。
那么，還有什么？
還記得ContentProvider中的getType嗎？
到目前為止，我們并沒(méi)有實(shí)現(xiàn)getType方法。而這并沒(méi)有對(duì)ContentProvider的使用造成任何影響。那么問(wèn)題來(lái)了。getType干嘛用的？什么時(shí)候用？
對(duì)于getType的解釋?zhuān)W(wǎng)上有兩種。
1. 用于對(duì)返回?cái)?shù)據(jù)的解析。判斷是一條數(shù)據(jù)，還是多條數(shù)據(jù)。若getType方法被實(shí)現(xiàn)，則按照實(shí)現(xiàn)方法解析，提高了工作效率。否則，系統(tǒng)自動(dòng)解析。
2. 避免new Intent(String action, Uri uri)方式無(wú)法啟動(dòng)activity。
對(duì)于解釋1，并未從找到官方的出處。而對(duì)于解釋2，不太明白！我用ContentProvider礙activity何事？
關(guān)于getType方法的實(shí)現(xiàn)，其原型注釋給出了答案。
方法返回的是MIME類(lèi)型的String形式。根據(jù)Uri的結(jié)尾不同，輸出也不同。
若Uri以Path結(jié)尾，則返回格式為
vnd.android.cursor.dir/vnd.<authority>.<path>
若Uri以id結(jié)尾，則返回格式為
vnd.android.cursor.item/vnd.<authority>.<path>
因此，我們實(shí)例中的getType()實(shí)現(xiàn)為
????@Override
????public?String?getType(Uri?uri)?{
????????Log.i(TAG,?"getType:?");????????String?authorityAndPath=MatcherConst.AUTHORITY+"."+DBConst.TABLE_PERSON;????????String?handerPath="vnd.android.cursor.dir/vnd.";????????String?handerID="vnd.android.cursor.item/vnd.";????????switch?(matcher.match(uri)){????????????case?MatcherConst.BY_NONE:????????????????return?handerPath+authorityAndPath;????????????case?MatcherConst.BY_AGE:????????????case?MatcherConst.BY_SEX:????????????case?MatcherConst.BY_NAME:????????????????return?handerID+authorityAndPath;????????????default:????????????????return?null;
????????}
????}本文主要介紹了Android中四大組件的ContentProvider的一些知識(shí)，覺(jué)得文章不錯(cuò)的喜歡的小伙伴可以關(guān)注加分享，也歡迎大家前來(lái)探討交流。
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