小贝子编程

每次更新数据库时从游标获取值



我有两个活动。一个是从edittext更新数据库中的值，在第二个活动中，我想把数据库中的这个值放到textview中。当我第一次更新值时，一切都很顺利，但第二次无法更新textview，我在textview值中看到了"0"。当我给出断点时，我发现我的光标不想第二次取值。有什么建议我该怎么办吗？这是活动生命周期的问题还是什么？这是我的密码。任何例子或建议对我都很有帮助。

public class DzienPierwszy extends AppCompatActivity {
Button button;
OpenHelper1 mDb;
TextView pp1,pp2,pp3,s1,s2,s3,p1,p2,p3,pn,sr,pt,nd;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.dzien_treningu);
p1 = (TextView) findViewById(R.id.p1);
p2 = (TextView) findViewById(R.id.p2);
p3 = (TextView) findViewById(R.id.p3);
s1 = (TextView) findViewById(R.id.s1);
s2 = (TextView) findViewById(R.id.s2);
s3 = (TextView) findViewById(R.id.s3);
pp1 = (TextView) findViewById(R.id.pp1);
pp2 = (TextView) findViewById(R.id.pp2);
pp3 = (TextView) findViewById(R.id.pp3);
pn = (TextView) findViewById(R.id.pn);
sr = (TextView) findViewById(R.id.sr);
pt = (TextView) findViewById(R.id.pt);
nd = (TextView) findViewById(R.id.nd);

Intent i = getIntent();
final String product = i.getStringExtra("cwiczenie ");
int lol1=0;
mDb = new OpenHelper1(this);
mDb.open();
// fetch data about 1 row in database table
Cursor test = mDb.fetchOneCwiczenie(product);
mDb.close();
if( test != null && test.moveToFirst() ){
//get value from column
lol1 = test.getInt(test.getColumnIndex("score"));
test.close();
}

p1.setText(String.valueOf(Math.round(lol1*0.55)));
p2.setText(String.valueOf(Math.round(lol1*0.79)));
p3.setText(String.valueOf(Math.round(lol1*0.67)));
s1.setText(String.valueOf(Math.round(lol1*0.67)));
s2.setText(String.valueOf(Math.round(lol1*0.91)));
s3.setText(String.valueOf(Math.round(lol1*0.79)));
pp1.setText(String.valueOf(Math.round(lol1*0.79)));
pp2.setText(String.valueOf(Math.round(lol1*1.03)));
pp3.setText(String.valueOf(Math.round(lol1*0.91)));
}
public void open(View view) {
Intent intent = new Intent(getApplicationContext(),TestActivity.class);
startActivity(intent);
}
}


public class OpenHelper1{

private static final String TAG = "TreningDbAdapter";
public DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private final ContentResolver resolver =null;
private final Context mCtx;
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "menadzerCwiczen1";
public static final String TABLE_CWICZENIA = "cwiczenia";
public static final String KEY_ID = "_id";
public static final String KEY_NAME = "name";
public static final String KEY_KIND = "kind";
public static final String KEY_URL = "url";
public static final String KEY_SCORE = "score";
public static final String KEY_SERIES = "series";
static final String PROVIDER_NAME = "com.example.jacek.gympartner.SQLite";
static final String URL = "content://" + PROVIDER_NAME + "/cwiczenia";
static final Uri CONTENT_URI = Uri.parse(URL);
private static HashMap<String, String> CWICZENIA_PROJECTION_MAP;
static final int CWICZENIA = 1;
static final int CWICZENIE_ID = 2;
static final UriMatcher uriMatcher;
static{
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI(PROVIDER_NAME, "cwiczenie", CWICZENIA);
uriMatcher.addURI(PROVIDER_NAME, "cwiczenia/#", CWICZENIE_ID);
}

private static final String DATABASE_CREATE =
"CREATE TABLE if not exists " + TABLE_CWICZENIA + " (" +
KEY_ID + " integer PRIMARY KEY autoincrement," +
KEY_NAME + " TEXT," +
KEY_KIND + " TEXT," +
KEY_URL + " TEXT," +
KEY_SCORE + " TEXT," +
KEY_SERIES + " integer" +
");";
/*
@Override
public boolean onCreate() {
Context context = getContext();
DatabaseHelper dbHelper = new DatabaseHelper(context);

mDb = dbHelper.getWritableDatabase();
return (mDb == null)? false:true;
}
@Nullable
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
return null;
}
@Nullable
@Override
public String getType(Uri uri) {
return null;
}
@Nullable
@Override
public Uri insert(Uri uri, ContentValues values) {
return null;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
return 0;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
return 0;
}
*/
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
Log.w(TAG, DATABASE_CREATE);


db.execSQL(DATABASE_CREATE);
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Pompki','Klatka piersiowa','https://www.youtube.com/watch?v=bwnidT3CB_Q',0,3)");
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Pompki na poręczach','Triceps','https://www.youtube.com/watch?v=Cufsu3IHhCo',0,3)");
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Odwrotne wiosłowanie','Plecy','https://www.youtube.com/watch?v=8qCn76yKhro',0,3)");
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Spięcia brzucha leżąc','Górna część mięśni brzucha','https://www.youtube.com/watch?v=VVcm4LdmIwM',0,3)");
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Unoszenie kolan','Dolna część mięśni brzucha','https://www.youtube.com/watch?v=Htx9Z8ZkiCg',0,3)");
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Skręty tułowia','Mięśnie skośne brzucha','https://www.youtube.com/watch?v=i7smKA3mgBU',0,3)");
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Przysiady','Uda','https://www.youtube.com/watch?v=NEduXlZ8zSk&t',0,3)");
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Wspięcia na palce','Mięśnie łydek','https://www.youtube.com/watch?v=Wri0VppFWCY',0,3)");
db.execSQL("INSERT INTO "+TABLE_CWICZENIA+"("+KEY_NAME+","+KEY_KIND+","+KEY_URL+","+KEY_SCORE+","+KEY_SCORE+") VALUES('Podciąganie na drążku','Mięśnie łydek','https://www.youtube.com/watch?v=7hM1iriAxx8',0,3)");

}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CWICZENIA);
onCreate(db);
}

}
public  OpenHelper1(Context ctx) {
this.mCtx = ctx;
}
public OpenHelper1 open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public OpenHelper1 read() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getReadableDatabase();
return this;
}
public void close() {
if (mDbHelper != null) {
mDbHelper.close();
}
}
public long createCwiczenie(String name,
String kind,
String url,
int score,
int series) {
mDbHelper.getWritableDatabase();
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, name);
initialValues.put(KEY_KIND, kind);
initialValues.put(KEY_URL, url);
initialValues.put(KEY_SCORE, score);
initialValues.put(KEY_SERIES, series);
return mDb.insert(TABLE_CWICZENIA, null, initialValues);
}

public void deleteCwiczenie(String name) {
mDb.execSQL("DELETE FROM " + TABLE_CWICZENIA + " WHERE " + KEY_NAME + "="" + name + "";" );
}

public void updateScore1(Uri uri,String name, int wynik) {
String str = "UPDATE "+TABLE_CWICZENIA+" SET "+KEY_SCORE+" = "+wynik+" WHERE "+KEY_NAME+" = '"+name+"'";
mDb.execSQL(str);
}

public void updateScore(String name, int wynik) {
String str = "UPDATE "+TABLE_CWICZENIA+" SET "+KEY_SCORE+" = "+wynik+" WHERE "+KEY_NAME+" = '"+name+"'";
mDb.execSQL(str);
}
public boolean deleteAllCwiczenia() {
int doneDelete = 0;
doneDelete = mDb.delete(TABLE_CWICZENIA, null , null);
Log.w(TAG, Integer.toString(doneDelete));
return doneDelete > 0;
}
public Cursor fetchCwiczeniaByName(String inputText) throws SQLException {
Log.w(TAG, inputText);
Cursor mCursor = null;
if (inputText == null  ||  inputText.length () == 0)  {
mCursor = mDb.query(TABLE_CWICZENIA, new String[] {KEY_ID,
KEY_NAME, KEY_KIND, KEY_URL, KEY_SCORE, KEY_SERIES},
null, null, null, null, null);
}
else {
mCursor = mDb.query(true, TABLE_CWICZENIA, new String[] {KEY_ID,
KEY_NAME, KEY_KIND, KEY_URL, KEY_SCORE, KEY_SERIES},
KEY_NAME + " like '%" + inputText + "%'", null,
null, null, null, null);
}
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public Cursor fetchAllcwiczenia() {
Cursor mCursor = mDb.query(TABLE_CWICZENIA, new String[] {KEY_ID,
KEY_NAME, KEY_KIND, KEY_URL, KEY_SCORE, KEY_SERIES},
null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public Cursor fetchOneCwiczenie(String name) {
String query = "SELECT * FROM " + TABLE_CWICZENIA + " WHERE name='"+name+"'";
Cursor c = mDb.rawQuery(query,null);

if(c != null) {
c.moveToFirst();
}
return c;
}
public Cursor fetchOneCwiczenie1(Uri uri,String name) {
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables(TABLE_CWICZENIA);

String query = "SELECT * FROM " + TABLE_CWICZENIA + " WHERE name='"+name+"'";
Cursor c = mDb.rawQuery(query,null);

if (c != null) {
// c.setNotificationUri(getContext().getContentResolver(), ContactsContract.AUTHORITY_URI);
}
return c;
}


public void insertSomeCwiczenia() {
createCwiczenie("Pompki","Klatka piersiowa","https://www.youtube.com/watch?v=bwnidT3CB_Q",20,3);
createCwiczenie("Pompki na poręczach","Triceps","https://www.youtube.com/watch?v=Cufsu3IHhCo",0,3);
createCwiczenie("Odwrotne wiosłowanie","Plecy","https://www.youtube.com/watch?v=8qCn76yKhro",0,3);
createCwiczenie("Spięcia brzucha leżąc","Górna część mięśni brzucha","https://www.youtube.com/watch?v=VVcm4LdmIwM",0,3);
createCwiczenie("Unoszenie kolan","Dolna część mięśni brzucha","https://www.youtube.com/watch?v=Htx9Z8ZkiCg",0,3);
createCwiczenie("Skręty tułowia","Mięśnie skośne brzucha","https://www.youtube.com/watch?v=i7smKA3mgBU",0,3);
createCwiczenie("Przysiady","Uda","https://www.youtube.com/watch?v=NEduXlZ8zSk&t",0,3);
createCwiczenie("Wspięcia na palce","Mięśnie łydek","https://www.youtube.com/watch?v=Wri0VppFWCY",0,3);
createCwiczenie("Podciąganie na drążku","Mięśnie łydek","https://www.youtube.com/watch?v=7hM1iriAxx8",0,3);
}

}
public class TestActivity extends AppCompatActivity {
TextView textView;
EditText editText;
Button button,button1;
OpenHelper1 mDb;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.test_layout);
textView = (TextView) findViewById(R.id.polecenie);
editText = (EditText) findViewById(R.id.wartosc);
button = (Button) findViewById(R.id.treningactivity);
button1 = (Button) findViewById(R.id.zapisz);
//button2 = (Button) findViewById(R.id.button);

mDb = new OpenHelper1(this);

Intent i = getIntent();
// getting attached intent data
final String product = i.getStringExtra("cwiczenie ");

button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int wynik = Integer.parseInt(editText.getText().toString());
mDb.open();
mDb.updateScore(product,wynik);

mDb.close();

}
});
/*
button2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mDb.open();
Cursor t = mDb.fetchOneCwiczenie(product);
int c = t.getInt(t.getColumnIndex("score"));
String k = Integer.toString(c);
textView1.setText(k);
mDb.close();
}
});
*/
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext().getApplicationContext(), DzienPierwszy.class);
i.putExtra("cwiczenie ", product);
startActivity(i);
}
});

}
}

您需要做的事情不止几件-

  1. 在您的内容提供商中，在将游标返回到客户端(在本例中为"活动")之前，您需要附加一个通知Uri。代码看起来像这样(这里需要根据您的提供商更改Authority URI)-

if (c != null) { c.setNotificationUri(getContext().getContentResolver(),ContactsContract.AUTHORITY_URI); } return c;

  1. 每次数据更新时，都需要调用以下行-

getContext().getContentResolver().notifyChange(ContactsContract.AUTHORITY_URI, null, syncToNetwork);

基本上什么点1&2的作用是通知底层数据层当前有一个具有活动游标的客户端，并且如果底层数据发生更改，则需要通知该客户端。如果你正在使用安卓系统中的任何内置数据提供商，如ContactsProvider/SmsProvider来读取联系人/SMS数据，点1&2会得到照顾的。

联系人提供商

  1. 在您的活动代码上，您需要执行以下操作cursor.registerContentObserver(mChangeObserver)。如果您改为使用一个封装在光标周围的Cursor适配器，那么这将得到解决。看看游标适配器的源代码-

CursorAdapter示例

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