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这是我的第一个内容提供者， 我被卡住了，因为我无法删除一行。由于我仍然无法使用Junit测试，因此我试图设置内容提供者每次传递一条指令。 我不明白为什么不工作，谢谢内容提供者无法删除SQLite中的行
以方便后续的热点：从FragmentAsList类的方法onContextItemSelected我打电话的ContentResolver的进入提供者类调用合同值和删除的平均值连接到数据库并返回一个int
我也使用CRUD方法附加了数据库类，请注意，在我从ContentResolver执行的删除调用中，有一个getAllRows方法，它连接到Db类，而不是由内容提供者，所以代码可能会出现混淆，但我目前无法使用JUNIT。
FragmentAsList
package ivano.android.com.ucanote;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.text.format.Time;
import android.util.Log;
import android.view.ContextMenu;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import ivano.android.com.ucanote.ivano.android.com.ucanote.db.Db;
import ivano.android.com.ucanote.ivano.android.com.ucanote.db.UcanContentProvider;
import ivano.android.com.ucanote.ivano.android.com.ucanote.db.UcanContract;
/**
* Created by ivano on 3/25/2015.
*/
public class FragmentAsList extends Fragment implements View.OnCreateContextMenuListener {
private SimpleCursorAdapter myCursorAdapter;
private ArrayAdapter<String> mValues;
//brought out from OnCreateView, have to be in all the class
List<String> tasks = new ArrayList<String>();
ListView listView;
Time today = new Time(Time.getCurrentTimezone());
Db myDb;
EditText etTasks;
public FragmentAsList() {
super();
}
public void populateView(){
Cursor cursor = myDb.getallRows();
String[] fromFieldNames = new String[]{UcanContract.Tasks._ID,};
int[] toViewId = new int[]{R.id.text_view};
//SimpleCursorAdapter myCursorAdapter;
myCursorAdapter = new SimpleCursorAdapter(getActivity(), R.layout.textview_pretty_cool, cursor, fromFieldNames,
toViewId, 0);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Add this line in order for this fragment to handle menu events.
setHasOptionsMenu(true);
//open Database
myDb = new Db(getActivity());
myDb.open();
}
@Override
public String toString() {
return super.toString();
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.menu_fragmentaslist, menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
// item + " " + item.getItemId());
switch (id) {
case R.id.add:
intent_comunicate.putExtra(getActivity().getPackageName(), "CIao Cipollino");
startActivityForResult(intent_comunicate, 123);
break;
case R.id.delete_all:
myDb.deleteAll();
Cursor cursor = myDb.getallRows();
String[] fromFieldNames = new String[]{UcanContract.Tasks.COLUMN_TASKS};
int[] toViewId = new int[]{R.id.text_view};
SimpleCursorAdapter myCursorAdapter;
myCursorAdapter = new SimpleCursorAdapter(getActivity(), R.layout.textview_pretty_cool, cursor, fromFieldNames, toViewId, 0);
listView.setAdapter(myCursorAdapter);
}
return super.onOptionsItemSelected(item);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 123) {
String string = data.getExtras().getString(getActivity().getPackageName());
Log.d("FragmentAsList", "stringa dall altra activity: " + string);
Toast.makeText(getActivity(), string, Toast.LENGTH_LONG).show();
///database insert
today.setToNow();
String timeCurrent = today.format("%Y-%m-%d %H:%M:%S");
myDb.insertRow(string, timeCurrent, null, null);
//database query
Cursor cursor = myDb.getallRows();
String[] fromFieldNames = new String[]{UcanContract.Tasks.COLUMN_TASKS};
int[] toViewId = new int[]{R.id.text_view};
SimpleCursorAdapter myCursorAdapter;
myCursorAdapter = new SimpleCursorAdapter(getActivity(), R.layout.textview_pretty_cool, cursor, fromFieldNames, toViewId, 0);
listView.setAdapter(myCursorAdapter);
}
}
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View hiddenList = inflater.inflate(R.layout.fragment_as_list, container, false);
// Get a reference to the ListView, and attach this adapter to it.
listView = (ListView) hiddenList.findViewById(R.id.list_hidden);
registerForContextMenu(listView);
populateView();
listView.setAdapter(myCursorAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// Intent explicitIntent =new Intent(getActivity(),DetailNote.class);
// startActivity(explicitIntent);
}
});
return hiddenList;
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
MenuInflater mi = getActivity().getMenuInflater();
mi.inflate(R.menu.context_menu, menu);
}
@Override
public boolean onContextItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.delete:
//TODO delete
registerForContextMenu(listView);
AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
int index = info.position;
String indexToString=Integer.toString(index);
long b=info.id;
Uri uri = Uri.parse(UcanContentProvider.CONTENT_URI + "/"
+ info.id);
getActivity().getContentResolver().delete(uri, indexToString, null);
//String indexString = Integer.toString(index);
Log.d("ivano.android.com.ucanote.FragmentAsList", "onContextItemSelected (line 160): the position is " + index);
// myDb.deleteRow(b);
//database query
Cursor cursor = myDb.getallRows();
String[] fromFieldNames = new String[]{UcanContract.Tasks.COLUMN_TASKS};
int[] toViewId = new int[]{R.id.text_view};
SimpleCursorAdapter myCursorAdapter;
myCursorAdapter = new SimpleCursorAdapter(getActivity(), R.layout.textview_pretty_cool, cursor,
fromFieldNames, toViewId, 0);
// SimpleCursorAdapter myCursorAdapter;
// myCursorAdapter = new SimpleCursorAdapter(getActivity(), R.layout.textview_pretty_cool, cursor, fromFieldNames, toViewId, 0);
listView.setAdapter(myCursorAdapter);
break;
case R.id.edit:
break;
case R.id.share:
break;
}
return super.onContextItemSelected(item);
}
}
的ContentProvider
package ivano.android.com.ucanote.ivano.android.com.ucanote.db;
import android.content.ContentProvider;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
public class UcanContentProvider extends ContentProvider {
public Db.DatabaseHelper myDBHelper;
public static final String AUTHORITY = "ivano.android.com.ucanote.db.UcanContentProvider";
public static final String PATH_TASKS="tasks";
public static final Uri BASE_CONTENT_URI = Uri.parse("content://" + AUTHORITY);
public static final Uri CONTENT_URI =BASE_CONTENT_URI.buildUpon().appendPath(PATH_TASKS).build();
@Override
public boolean onCreate() {
//TODO not sure i need it see Android for busy programmers page 979, I have it already as constructor in Db.java that has the Helper
//as inner class
myDBHelper = new Db.DatabaseHelper(getContext());
return false;
}
//
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
//Using SQLiteQueryBuilder instead of query() method
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables(UcanContract.Tasks.DATABASE_TABLE);
Cursor cursor = qb.query(myDBHelper.getReadableDatabase(), projection, selection, selectionArgs, null, null, sortOrder);
cursor.setNotificationUri(getContext().getContentResolver(), uri);
return cursor;
}
@Override
public String getType(Uri uri) {
return null;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
return null;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
int count = myDBHelper.getWritableDatabase().delete(UcanContract.Tasks.DATABASE_TABLE,
UcanContract.Tasks._ID + " = " + selection, selectionArgs);
getContext().getContentResolver().notifyChange(uri, null);
return count;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
return 0;
}
}
合同类
package ivano.android.com.ucanote.ivano.android.com.ucanote.db;
import android.provider.BaseColumns;
public class UcanContract{
public static final class Tasks implements BaseColumns{
public static final String COLUMN_TASKS = "task";
public static final String COLUMN_DATE = "date";
public static final String COLUMN_URGENCY = "urgency";
public static final String COLUMN_TAG = "tag";
public static final String[] ALL_ROWS=new String[]{_ID, COLUMN_TASKS, COLUMN_DATE, COLUMN_URGENCY, COLUMN_TAG};
public static final String DATABASE_TABLE="table1";
}
}
最后DB
package ivano.android.com.ucanote.ivano.android.com.ucanote.db;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
/**
* Created by ivano on 4/8/2015.
*/
public class Db {
private static final String TAG="Db";
//TODO check if all the fields are used,
// expecially TAG, ALL KEYS and columns, and what is the function of DB info?
//fields
//DB info
public static final String DATABASE_NAME = "db";
//always remember to change this if I are going to update the DB!
public static final int DATABASE_VERSION=1;
//create
private static final String DATABASE_CREATE_SQL=
"CREATE TABLE " + UcanContract.Tasks.DATABASE_TABLE
+ " (" + UcanContract.Tasks._ID+ " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ UcanContract.Tasks.COLUMN_TASKS + " TEXT NOT NULL, "
+ UcanContract.Tasks.COLUMN_DATE + " TEXT, "
+ UcanContract.Tasks.COLUMN_URGENCY +" TEXT, "
+ UcanContract.Tasks.COLUMN_TAG +" TEXT " +
");";
private final Context context;
public DatabaseHelper myDBHelper;
private SQLiteDatabase db;
public Db (Context ctx) {
this.context = ctx;
myDBHelper=new DatabaseHelper(context);
}
public Db open() {
db= myDBHelper.getWritableDatabase();
return this;
}
public void close(){
myDBHelper.close();
}
public long insertRow (String task,String date, String urgency, String tag) {
ContentValues initialValues = new ContentValues();
initialValues.put(UcanContract.Tasks.COLUMN_TASKS, task);
initialValues.put(UcanContract.Tasks.COLUMN_DATE, date);
initialValues.put(UcanContract.Tasks.COLUMN_URGENCY, urgency);
initialValues.put(UcanContract.Tasks.COLUMN_TAG, tag);
return db.insert(UcanContract.Tasks.DATABASE_TABLE,null,initialValues);
}
//delete a row from the db by _id
public boolean deleteRow(long rowId) {
String where = UcanContract.Tasks._ID + "=" + rowId;
//db.delete(DATABASE_TABLE, where, null) ;
return db.delete(UcanContract.Tasks.DATABASE_TABLE, where, null) != 0;
}
public void deleteAll(){
Cursor c=getallRows();
long rowId=c.getColumnIndex(UcanContract.Tasks._ID);
if (c.moveToFirst()) {
do {
deleteRow(c.getLong((int) rowId));
}
while (c.moveToNext());
}
c.close();
}
public Cursor getallRows(){
String where=null;
Cursor c=db.query(true, UcanContract.Tasks.DATABASE_TABLE, UcanContract.Tasks.ALL_ROWS,where,null,null,null,null,null);
if (c!= null){
c.moveToFirst();
}
return c;
}
public Cursor getRow(long rowId){
String where =UcanContract.Tasks._ID+"=" +rowId;
Cursor c=db.query(true, UcanContract.Tasks.DATABASE_TABLE, UcanContract.Tasks.ALL_ROWS,where,null,null,null,null,null);
if(c!= null){
c.moveToFirst();
}
return c;
}
public boolean updateRow(long rowId,String task,String date, String urgency,String tag){
String where =UcanContract.Tasks._ID+"="+rowId;
ContentValues newValues =new ContentValues();
newValues.put(UcanContract.Tasks.COLUMN_TASKS,task);
newValues.put(UcanContract.Tasks.COLUMN_DATE, date);
newValues.put(UcanContract.Tasks.COLUMN_URGENCY, urgency);
newValues.put(UcanContract.Tasks.COLUMN_TAG, tag);
return db.update(UcanContract.Tasks.DATABASE_TABLE,newValues,where,null)!=0;
}
public static class DatabaseHelper extends SQLiteOpenHelper{
DatabaseHelper(Context context){
super (context,DATABASE_NAME,null,DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE_SQL);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG,"Upgrading application's database from version"
+oldVersion+ " to "+newVersion+
" ,which will destroy all the old data!");
db.execSQL("DROP TABLE IF EXISTS "+ UcanContract.Tasks.DATABASE_TABLE);
onCreate(db);
}
}
}