您需要在自己的应用程序中实现ContentProvider。如下所示,Content Provider管理应用程序内部和外部之间共享数据的访问:
首先,创建一个类来实现Content Provider:
public class MyContentProvider extends ContentProvider {
public static final Uri CONTENT_URI = Uri.parse("content://com.example.myapp.provider/data");
private static final int DATA_LIST = 1;
private static final int DATA_ITEM = 2;
private static final UriMatcher uriMatcher;
static {
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI("com.example.myapp.provider", "data", DATA_LIST);
uriMatcher.addURI("com.example.myapp.provider", "data/#", DATA_ITEM);
}
@Override
public boolean onCreate() {
// initialize your database or files here
return true;
}
@Override
public String getType(Uri uri) {
switch (uriMatcher.match(uri)) {
case DATA_LIST:
return "vnd.android.cursor.dir/vnd.com.example.myapp.provider.data";
case DATA_ITEM:
return "vnd.android.cursor.item/vnd.com.example.myapp.provider.data";
default:
throw new IllegalArgumentException("Unsupported URI: " + uri);
}
}
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
Cursor cursor = null;
switch (uriMatcher.match(uri)) {
case DATA_LIST:
cursor = // query the database or files here and return the cursor
break;
case DATA_ITEM:
// handle single item query here
break;
default:
throw new IllegalArgumentException("Unsupported URI: " + uri);
}
return cursor;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
long id = // insert data into database or files here
return ContentUris.withAppendedId(CONTENT_URI, id);
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
int count = // update data in database or files here
return count;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
int count = // delete data from database or files here
return count;
}
}
然后,在AndroidManifest.xml文件中添加以下内容:
这会向Android系统注册ContentProvider。最后,在您的