本文介绍了Android DBFlow和CursorLoader的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
任何人都知道如何在DBFlow中使用cursorLoader吗?我看到了这个问题，但这没有添加到DBFlow中.
Anyone knows how to use cursorLoader with DBFlow ? I seen this issue but this is not added to DBFlow.
谢谢.
推荐答案
您可以找到官方文档此处，或者您也可以按照我的方式实现
You can find official docs here or you can implement it the way i have
DBFlow已使用3
DBFlow ver used 3
//我已经编辑了答案&为
//I have edited my answer & provided easier way for content provider part below
将此添加到应用程序内部清单
add this to manifest inside application
<provider
android:authorities="com.hashx19.pristinekashmir.mycontentprovider"
android:exported="false"
android:name=".MyContentProvider"/>
创建名为MyContentProvider&的Java文件.复制下面的代码&根据您的项目替换AUTHORITY，ENDPOINT，AppDatabase(您的数据库名称)，TableClassName.
Create java file named MyContentProvider & copy below code in it& replace AUTHORITY ,ENDPOINT, AppDatabase(Your database name) ,TableClassName as per you project.
import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.CursorIndexOutOfBoundsException;
import android.net.Uri;
import com.hashx19.pristinekashmir.MySQLiteHelper;
import com.raizlabs.android.dbflow.annotation.ConflictAction;
import com.raizlabs.android.dbflow.config.FlowManager;
import com.raizlabs.android.dbflow.structure.ModelAdapter;
import java.util.Arrays;
import java.util.HashSet;
/**
* Created by Filu on 8/25/2016.
*/
public class MyContentProvider extends ContentProvider {
public static final String AUTHORITY = "com.hashx19.pristinekashmir.mycontentprovider";
private static final String ENDPOOINT = "feeds";
// @ContentUri(path = ENDPOOINT, type = ContentUri.ContentType.VND_MULTIPLE + ENDPOOINT)
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY
+ "/" + ENDPOOINT);
private static final int feeds_CONTENT_URI = 0;
private static final UriMatcher MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
static {
MATCHER.addURI(AUTHORITY, ENDPOOINT, feeds_CONTENT_URI);
}
;
@Override
public final String getType(Uri uri) {
String type = null;
switch(MATCHER.match(uri)) {
case feeds_CONTENT_URI: {
type = "vnd.android.cursor.dir/" +ENDPOINT;
break;
}
default: {
throw new IllegalArgumentException("Unknown URI" + uri);
}
}
return type;
}
@Override
public boolean onCreate() {
return false;
}
@Override
public final Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
android.database.Cursor cursor = null;
switch(MATCHER.match(uri)) {
case feeds_CONTENT_URI: {
cursor = FlowManager.getDatabase("AppDatabase").getWritableDatabase().query("TableClassName", projection, selection, selectionArgs, null, null, sortOrder);
break;
}
}
if (cursor != null) {
cursor.setNotificationUri(getContext().getContentResolver(), uri);
}
return cursor;
}
@Override
public final Uri insert(Uri uri, ContentValues values) {
switch(MATCHER.match(uri)) {
case feeds_CONTENT_URI: {
ModelAdapter adapter = FlowManager.getModelAdapter(FlowManager.getTableClassForName("AppDatabase", "TableClassName"));
final long id = FlowManager.getDatabase("AppDatabase").getWritableDatabase().insertWithOnConflict("TableClassName", null, values, ConflictAction.getSQLiteDatabaseAlgorithmInt(adapter.getInsertOnConflictAction()));
getContext().getContentResolver().notifyChange(uri, null);
return ContentUris.withAppendedId(uri, id);
}
default: {
throw new IllegalStateException("Unknown Uri" + uri);
}
}
}
@Override
public final int delete(Uri uri, String selection, String[] selectionArgs) {
switch(MATCHER.match(uri)) {
case feeds_CONTENT_URI: {
long count = FlowManager.getDatabase("AppDatabase").getWritableDatabase().delete("TableClassName", selection, selectionArgs);
if (count > 0) {
getContext().getContentResolver().notifyChange(uri, null);
}
return (int) count;
}
default: {
throw new IllegalArgumentException("Unknown URI" + uri);
}
}
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
switch(MATCHER.match(uri)) {
case feeds_CONTENT_URI: {
ModelAdapter adapter = FlowManager.getModelAdapter(FlowManager.getTableClassForName("AppDatabase", "TableClassName"));
long count = FlowManager.getDatabase("AppDatabase").getWritableDatabase().updateWithOnConflict("TableClassName", values, selection, selectionArgs, ConflictAction.getSQLiteDatabaseAlgorithmInt(adapter.getUpdateOnConflictAction()));
if (count > 0) {
getContext().getContentResolver().notifyChange(uri, null);
}
return (int) count;
}
default: {
throw new IllegalStateException("Unknown Uri" + uri);
}
}
}
}
然后，当重写Loader方法时，会执行类似的操作
then when overriding Loader methods do something like this
getLoaderManager().initLoader(1, null, this);
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
String selection, sortOrder;
String[] selectionArgs, projection;
selection = ...;
selectionArgs = ...;
sortOrder = ...;
projection= new String[]{"id","date", "link","title","content","excerpt","author",};
CursorLoader cursorLoader = new CursorLoader(getContext(),MyContentProvider.CONTENT_URI, projection,null,null,null);
return cursorLoader;
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
TableClass post = new TableClass();
while (!cursor.isAfterLast()) {
try{
post.setId(cursor.getInt(cursor.getColumnIndex("id")));
}catch (NullPointerException e){
e.printStackTrace();
}catch (CursorIndexOutOfBoundsException c){
c.printStackTrace();
}
}
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
}
已编辑
想出了实现内容提供者的简便方法.
Figured out easier way to implement content provider .
-
将此添加到清单中/或如果已经添加了提供者代码，则可以通过这种方式进行修改.
add this to your manifest / or modify this way if you already have added Provider code .
将您的AppDatabase类修改为
modify your AppDatabase Class as
@ContentProvider(authority = AppDatabase.AUTHORITY,
database = AppDatabase.class,
baseContentUri = AppDatabase.BASE_CONTENT_URI)
@Database(name = AppDatabase.NAME, version = AppDatabase.VERSION)
public class AppDatabase {
public static final String NAME = "AppDatabase"; // we will add the .db extension
public static final int VERSION = 2;
public static final String AUTHORITY = "com.hashx19.pristinekashmir.dbflowcontentprovider";
public static final String BASE_CONTENT_URI = "content://"; }
将要用作提供程序的每个表修改为
modify each table you want to use as provider as
@TableEndpoint(name = PostData.ENDPOINT, contentProvider = AppDatabase.class)
@Table(database = AppDatabase.class ,allFields = true ,name = PostData.ENDPOINT)
public class PostData extends BaseModel {
public static final String ENDPOINT = "PostData";
@ContentUri(path = ENDPOINT, type = ContentUri.ContentType.VND_MULTIPLE + ENDPOINT)
public static final Uri CONTENT_URI = Uri.parse(AppDatabase.BASE_CONTENT_URI + AppDatabase.AUTHORITY
+ "/" + ENDPOINT);
@PrimaryKey
public int id;
public String image;
}
要像在Cursor Loader中一样使用Content provider，请在这种情况下使用TableName.CONTENT_URI
For using Content provider as in Cursor Loader use TableName.CONTENT_URI as in this case
CursorLoader cursorLoader = new CursorLoader(getContext(),PostData.CONTENT_URI,projection,null,null,null);
这篇关于Android DBFlow和CursorLoader的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！